memo

__memo

###
PERSONAL COLLECTION OF MEMO
by https://github.com/niainaLens
###

_certifications

## DevOps
+ LPIC DevOps Tools Engineer

## Cloud
+ GCP
+ AWS
+ AZURE

## Linux
+ LPIC 1, 2, 3

## Network
+ CISCO

_cloud_provider

--- GCP

## Container
  + Kubernetes                              |Borg

  + Istio
      Service Mesh

## Database
  + BigQuery
  + BigTable    |Hbase
  + CloudSQL
  + CloudSpanner
  + MemoryStore

## Serverless
  + CloudFunction

--- AWS

--- AZURE

_glossary

A
*A/B Testing                                            |Release management, Delivery, Marketing
  delivery of 2 versions of products
APM: Application Performance Monitoring                 |Monitoring, Elastic, AppDynamics, Dynatrace
*AT-LEAST ONCE:                                         |Message delivery, Queue, Message broke
  message will be delivered at least one time, but there may be duplicates
*AT-MOST ONCE:                                          |Message delivery, Queue, Message broker
  message is delivered at most one time, with the possibility of not being delivered at all
*ATOMIC DESIGN: reusable action & workflow              |Development, DevOps, Design

B
BAFO: Best And Final Offer                              |Management, Project
BCP: Business Continuity Plan (*PCA)                    |Management, Agile

C
CAB: Change Advisory Board                              |Deployment
*CC-BY-NC-SA: Licence Creative Commons                  |Licence
*Canary Release                                         |Release Management, Delivery
  delivery to restricted users before production
CDN: Content Delivery Network                           |Dev, Network, Infrastructure
*Circuit Breaker:                                       |Resilience, Design pattern
  autostop failed service to prevent cascading failures in a distributed system
CPU: Central Processing Unit                            |Machine
*CUTOVER PLAN:                                          |Agile
  actions plan for a big change of old technology to a new one (go-live, go-prod)
D
DAN: Do Anything Now                                    |AI
*Dark Launch                                            |Deployment, Release Management
  release feature to limited users/environments
DoD: Definition Of Done                                 |Agile, Scrum
DBT: Data Build Tools                                   |DBT, Data, Analytics
DLQ: Dead Letter Queue                                  |Queue
*Dilbert Principle (*Peter Principle):                  |Management
  companies tend to promote incompetent employees to management to minimize their ability to harm productivity
DRP: Disaster Recovery Plan                             |Cloud
*DRY-RUN:                                               |Testing, CI/CD
  run without applying
*Dunbar Number:                                         |Management, Agile
  theory that limit to number of people we can maintain stable social relationships at once
DX: Developer eXperience                                |Development


E
*EXACTLY ONCE:                                          |Message delivery, Queue, Message broker
  message is delivered exactly one time, without duplicates/omissions, then disappear
*EXPONENTIAL BACKOFF:                                   |Network, Algorithm
  progressively increases the time between successive retries
F
*FACILITY MANAGEMENT:                                   |Management, Agile
  management supporting people, ensures the functionality, comfort, safety, sustainability and efficiency of the built environment
FAIR: Findable, Accessible, Interoperable, Reusable     |Data
*FALLBACK:                                              |Security, DevOps
  alternative option used when the primary plan is not successful/unavailable
FTT: Failure To Tolerate                                |Security, Cloud

G
*Gemba:                                                 |Management, Agile, Lean
  process to Go, Look and See, how the work is done
GPO: Group POlicy                                       |Security
GPU: Graphical Processing Unit                          |Machine

H
HPC: High Performance Computing
*HUSHLOGIN: message on login banner in Linux for individual user (suppress MOTD)   |Linux

I
*Ikigai                                                 |Personal Development
  Japanese concept for perso dev
*Iron Triangle:                                         |Project management
  Project management triangle with triple constraints: Cost, Scope, Price
*ISO 26000:
  Norm RSE                                              |RSE
*ISO 27001:                                             |Security
  international standard for information systems security to define the Information Security Management System (ISMS)
ISMS: Information Security Management System            |Security
I&A: Inspect & Adapt                                    |Agile, SAFe

J

K
KB: Knowledge Base                                      |Agile, Doc
KISS: Keep It Simple Stupid                             |Agile

L
*LIFT AND SHIFT (*REHOSTING/ REPLATFORMING):            |Cloud, Migration
  Move server to cloud as it is, without redesign
*LIVENESS PROBE                                         |Kubernetes, Probe, Healthcheck
  determine if the application is running and responsive (not accept traffic yet, see Readiness Probe)
LUKS: Linux Unified Key Setup                           |Linux

M
MEAT: Most Economically Advantageous Tender             |Management, Project
MTBF: Mean Time Before Failure                          |Infrastructure, Metric
MTTA: Mean Time To Acknowledge                          |Infrastructure, Metric
MTTF: Mean Time To Failure                              |Infrastructure, Metric
MTTR: Mean Time To Recovery                             |Infrastructure, Metric
MVP: Minimum Viable Product                             |Development, Agile

N

O
ORM: Object-Relational Mapping                          |Database
*OCKHAM'S RAZOR:                                         |Agile, Principle, DevOps
  less is better, eliminate all unlikely hypothesis, parsimony principle
  -> https://www.linkedin.com/posts/jeanbaptistemusso_rasoir-dockham-wikip%C3%A9dia-activity-7019270010028052480-txnE?utm_source=share&utm_medium=member_desktop

P
*PETER PRINCIPLE: (*Dilbert Principle)                  |Management
  employees are promoted based on success until they attain their "level of incompetence" and are no longer successful
PCA: Plan de Continuité d'Activité (*BCP)          |Management, Agile
PCI-DSS: Payment Card Industry Data Security Standard   |Security, RGPD
PDCA: Plan Do Check Adjust                              |Agile
PoLP: PRINCIPLE of LESS PRIVILEGE                       |Security
*PORT-KNOCKING:                                         |Network, Security, Firewall
  open closed ports by sending network packets containing special information
PQQ: Pre-Qualification Questionnaire                    |Management, Project

Q
*QUORUM:                                                |Management
  minimum number of people needed to hold meetings or make decisions during certain company meetings

R
RACI: Responsible, Accountable, Consulted, Informed     |Management
RAT: Riskiest Assumption Test                           |Development, Agile, Test
RCU: Référentiel Client Unique (*SCV)                   |Database, Marketing
*READINESS PROBE                                        |Kubernetes, Probe, Healthcheck
  determine if a container is ready to accept traffic and to be plugged to the system (after Liveness Probe OK)
*REHOSTING (*LIFT AND SHIFT/ REPLATFORMING):            |Cloud, Migration
  Move server to cloud as it is, without redesign
REPL: Read-Eval-Print Loop                              |Programming
*REPLATFORMING (*LIFT AND SHIFT/ REHOSTING):            |Cloud, Migration
  Move server to cloud as it is, without redesign
*RESILIENCE:                                            |Security
  adaptation to crash, I crash Others not
RETEX: Retour d'Experience                              |Management, Agile
RFI: Request For Information                            |Management, Project
RFP: Request For Proposal                               |Management, Project
RFQ: Request For Quotation                              |Management, Project
ROAM: Resolved Owned Accepted Mitigated                 |Management, Agile, SAFe, Risk management
RPO: Recovery Point Objective                           |Management, Agile
RTE: Release Train Engineer                             |Management, Agile, SAFe
RTO: Recovery Time Objective                            |Management, Agile

S
SAST: Static Application Security Testing               |Security
SCIM: System for Cross-domain Identity Management       |IAM, Identity, Cloud
SCV: Single Client View (*RCU)                          |Database, Marketing
SKU: Stock Keeping Units                                |Azure, Cloud, Microsoft
SLA: Service Level Agreement                            |Agile, Project management, Support service
SLC: Simple Lovable Complete                            |Agile, Project management
*SLASHDOT EFFECT/ SLASDOTTING                           |Security
  temporary surge in traffic to a website
SLO: Service Level Objectives                           |Agile, Project management
SNS: Simple Notification Service                        |AWS
SSS: Shamir's Secret Sharing                            |Vault, Security, Encryption

T
*Tensor                                                 |Machine Learning
  Multi-dimensional matrix
TDD: Test Driven Development                            |Agile, Principle, Dev
TPU: Tensor Processing Unit                             |Machine, Machine Learning
Two-SV: Two-Steps Verification (*2-SV)                  |Security, Cloud

U
DX: User eXperience                               |Development

V

W
*Wideband Delphi                                  |Management
  Estimation method, diverge-converge
WAF: Web Application Firewall                           |Infrastructure
*Watermelon Metrics                                     |Agile, Marketing
  vanity metrics, hype but not representative metrics
WSJF: Weighted Shortest Job First                  |Agile, SAFe

X

Y
YAGNI: You Ain’t Gonna Need It                      |Agile, Principle, DevOps

Z
*Zero Trust                                               |Security
  strict access controls and not trusting anyone by default, continuous validation on every stage of interaction

0

1

2
2-SV: 2-Steps Verification (Two-SV)                         |Security, Cloud

3

4

5

6

7

8

9

_issues

--- DOCKER

## docker in wsl/wsl2
  "failed to start daemon: Error initializing network controller ... iptable"
  --> https://github.com/microsoft/WSL/issues/6655
    $ sudo update-alternatives --set iptables /usr/sbin/iptables-legacy
    $ sudo update-alternatives --set ip6tables /usr/sbin/ip6tables-legacy
    $ sudo dockerd &
    or
    $ sudo dockerd --debug --iptables=false &

_middleware_saas

--> https://github.com/awesome-selfhosted/awesome-selfhosted
--> https://github.com/awesome-selfhosted/awesome-selfhosted/blob/master/non-free.md


====================
==   MIDDLEWARE   ==
====================

--- ARCHITECTURE

  - OPEX

--- INFRA AS CODE

## Configuration management
  - ANSIBLE
  - chef
  - puppet

## Infrastructure build
  - TERRAFORM
  - Cloud Formation

## Image build
  - PACKER
  - DOCKER

## Containerization
  - DOCKER
  - Cri-o

## Container orchestrator
  - DOCKER-COMPOSE
  - KUBERNETES

--- DEV

## SCM
  - Git
  - Mercurial

## SCM GUI
  - BitBucket                           |CI/CD
  - Github                              |CI/CD
  - GITLAB                              |CI/CD

## Code quality review
  - SONARQUBE
  - Selenium

--- CODE COLLABORATION/REVIEW

  - GITLAB
  - Gerrit
  - Gitea

--- CI/CD

  - GITLAB-CI
  - Jenkins
  - Rundeck

--- CMDB

  - Git (YAML)
  - Insight (JIRA)

--- SECURITY

## Vault
  - ansible-vault
  - VAULT (hashicorp)

## WAF
  - Wordfence (wordpress plugin)

--- DATABASE

## RDBMS
  - MySQL
  - PostgreSQL
  - OracleDB
  - CLOUDSQL

## NoSQL
  - MongoDB

## Database config management
  - Liquibase
  - SonarQube

## Time series
  - influxDB

--- SECURITY

## Static application security testing (SAST)
  - Gitleaks

--- TEST

## load/performance testing
  - Apache JMeter
  - NeoLoad

--- IDE/TOOLS

## FOR DOCKER
  - Portainer

## FOR KUBERNETES
  - Lens

## IDE
  - VSCode

--- IDENTITY MANAGEMENT

  - LDAP
  - Keycloak
  - Auth0
  - Authentik

--- PROJECT MANAGEMENT

## ITIL
  - Redmine

## AGILE
  - JIRA                        |Ticketing

--- TICKETING/ HELPDESK

  - GLPI
  - JIRA

--- MONITORING

## Cloud provider
    - GCP: Stackdriver
    - AWS:
    - Azure:

## Container monitor
  - cadvisor
  - telegraf

## Data
    - Datadog
    - Splunk

## Observability
    - Kibana
    - Grafana
    - Dynatrace

--- INVENTORY

  - GLPI                          |Ticketing
  - OCS Inventory

--- DOCUMENTATION

  - Wiki
      - DokuWiki
      - Wiki.js
  - Alfresco
  - ReadTheDocs

  /SaaS/
  - Confluence (JIRA)
  - SharePoint

--- COMMUNICATION

  - Slack
  - Discord
  - Teams

--- MAIL

  - Postfix
  - Zimbra                            |Zimbra Cloud

--- OPEN/PROPRIETARY

## Container
  Kubernetes --> Borg                  |GKE, EKS, AKS

## Database
  HBase                                 |GCP BigTable

====================
==      SAAS      ==
====================

--- AGILE

  - Klaxoon
  - Gather town

--- Code collaboration

  - GITLAB
  - Github
  - BitBucket

--- CI/CD

  - GITLAB-CI
  - Github Action
  - Azure DevOps

--- CMDB

  - Gitlab/Github
  - Insight (JIRA)

--- IDENTITY MANAGEMENT

## Single-Sign-On
  - Auth0
  - Office365

--- REGISTRY

## Container/Image registry
  - Amazon ECR (Elastic Container Registry)     |AWS
  - Azure Container Registry                    |Azure
  - Dockerhub
  - Google Artifact Registry                    |GCP
  - ttl.sh

--- SHIPPING

  - UPS
  - Chronopost
  - Mondial Relay

--- PAYMENT

  - Paypal
  - Payline
  - Adyen

--- TAX

  - Avalara

--- TICKETING

## ITIL
  - ServiceNow

## AGILE
  - JIRA
  - Trello

--- DNS REGISTRAR

  - Akamai
  - Gandi
  - GoDaddy
  - LWS

--- MAIL

## Mail service
  - MS Office365
  - Google Workspace
  - Zimbra Cloud

## Mail marketing
  - Google Workspace
  - SFMC (SalesForce Marketing Cloud)
  - Mailjet
  - Mailchimp
  - Sendgrid

--- DOCUMENTATION

  - Confluence (JIRA)
  - SharePoint
  - ReadTheDocs

--- MISC

  - Bazzarvoice
      rating & opinion to e-commerce product

_misc

--- naming convention

TYPE_SOMETHING_NUMBER
  ex: - a mailing list for group of mail
        [email protected]
      - a bucket in google storage
        gs_PROJECT_LOCATION_NUMBER -> gs_project_ew1_1
      - a server compute engine
        cmp_PROJECT_LOCATION_NUMBER -> cp_project_ew1_1

## resources naming pattern
-> https://stepan.wtf/cloud-naming-convention/
[prefix/org]-[resource_type]-[project]-[env]-[location]-[short_description]-[suffix/number]

--- MIGRATION

## cloud migration strategies
  https://bluexp.netapp.com/blog/aws-cvo-blg-strategies-for-aws-migration-the-new-7th-r-explained
  https://drive.google.com/file/d/16TcsxMpjL0Uda_IUj6UF0RS55Q9bW0XG/view?usp=sharing
  
  + Gartner’s 5 Rs Model
    - Rehost (lift-and-shift)
        Move apps to the cloud without major changes.
        Use Case: Quick migration with minimal effort, suitable for apps compatible with cloud infrastructure (cloud native apps)
    - Refactor (re-architecting)
        Modify existing apps to better fit the cloud environment.
        Use Case: Necessary for apps needing significant changes to leverage cloud benefits fully.
    - Revise
        Partially modify and optimize apps for the cloud, including some redesign efforts.
        Use Case: apps requiring enhancements but not a complete overhaul.
    - Rebuild
        Recreate apps from scratch using cloud-native technologies.
        Use Case: Ideal for achieving maximum performance, scalability, and agility using cloud-native features.
    - Replace
        Swap out existing apps with new, often SaaS-based, solutions.
        Use Case: Best for outdated apps where a suitable cloud-based alternative exists.

  + AWS 6 Rs Model
    - Rehosting (Lift-and-Shift)
        Move apps to the cloud without significant changes.
        Use Case: Quick and straightforward migration for compatible apps.
    - Replatforming (Lift, Tinker, and Shift)
        Make minor optimizations for the cloud without changing the core architecture.
        Use Case: apps that can benefit from cloud services with minimal adjustments.
    - Repurchasing (Drop-and-Shop)
        Replace existing apps with cloud-based alternatives (SaaS).
        Use Case: When suitable cloud solutions are available, reducing custom development needs.
    - Refactoring / Re-architecting
        Reimagine and modify apps to fully leverage cloud capabilities.
        Use Case: apps needing significant changes to meet new business requirements.
    - Retire
        Shut down unnecessary apps.
        Use Case: Legacy apps that are no longer useful, saving costs and resources.
    - Retain (Revisit)
        Keep certain apps on-premises due to specific needs or constraints.
        Use Case: apps that must remain on-premises for various reasons, such as regulatory requirements.

  + AWS 7 Rs Model
    - Rehosting (Lift-and-Shift)
        Move apps to the cloud without significant changes.
        Use Case: Quick and straightforward migration for compatible apps.
    - Replatforming (Lift, Tinker, and Shift)
        Make minor optimizations for the cloud without changing the core architecture.
        Use Case: apps that can benefit from cloud services with minimal adjustments.
    - Repurchasing (Drop-and-Shop)
        Replace existing apps with cloud-based alternatives (SaaS).
        Use Case: When suitable cloud solutions are available, reducing custom development needs.
    - Refactoring / Re-architecting
        Reimagine and modify apps to fully leverage cloud capabilities.
        Use Case: apps needing significant changes to meet new business requirements.
    - Retire
        Shut down unnecessary apps.
        Use Case: Legacy apps that are no longer useful, saving costs and resources.
    - Retain (Revisit)
        Keep certain apps on-premises due to specific needs or constraints.
        Use Case: apps that must remain on-premises for various reasons, such as regulatory requirements.
    - Relocate
        Move entire data centers or large portions of infrastructure to the cloud with minimal changes, often involving virtual machines.
        Use Case: When large-scale infrastructure migration is required without modifying individual apps.

_pc_app

--- SYSTEM VARS
  ARCH=$(dpkg --print-architecture)
  KERNEL_NAME=$(uname -s)
  KERNEL_RELEASE=$(uname -r)
  LSB_RELEASE_OS=$(lsb_release -is)
  LSB_RELEASE_VERSION=$(lsb_release -rs)
  LSB_RELEASE_CODENAME=$(lsb_release -cs)
  DIR_KEYRING="/etc/apt/keyrings"
  DIR_GPG="/etc/apt/trusted.gpg.d"

--- APP

## dependencies
+ apt package
  - apt-transport-https   |code, gcloud, helm, kubectl, sublime-text
  - bash-completion     |bash, kubectl
  - build-essential
  - ca-certificates   |docker, gcloud, kubetcl
  - curl    |docker, kubectl, teams
  - file
  - git
  - gpg   |code
  - gnupg   |gcloud
  - gnome-keyring   |VSCode* (https://code.visualstudio.com/docs/editor/settings-sync#_troubleshooting-keychain-issues)
  - gnupg   |docker
  - lsb-release   |docker
  - procps
  - python3   |ansible
  - python3-pip   |ansible
  - vim
  - wget    |code

+ pip package
  - openai>=0.18.1    |codex-cli
  - psutil>=5.9.0     |codex-cli

## package manager
+ apt key (root:root 644)
  - ansible
      $ apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 93C4A3FD7BB9C367
  - brave
      $ curl -fsSLo ${DIR_KEYRING}/brave-browser.gpg https://brave-browser-apt-release.s3.brave.com/brave-browser-archive-keyring.gpg
  - docker
      $ curl -fsSL https://download.docker.com/linux/debian/gpg | sudo gpg --dearmor -o ${DIR_KEYRING}/docker.gpg
  - hashicorp (terraform, vault, consul, packer)
      $ wget -O- https://apt.releases.hashicorp.com/gpg | gpg --dearmor | sudo tee ${DIR_KEYRING}/hashicorp.gpg
  - helm
      $ curl https://baltocdn.com/helm/signing.asc | sudo gpg --dearmor -o ${DIR_KEYRING}/helm.gpg
  - gcloud
      $
  - google-cloud (gcloud, kubernetes)
      $ curl -fsSLo ${DIR_KEYRING}/google-cloud.gpg https://packages.cloud.google.com/apt/doc/apt-key.gpg
  - microsoft (code, teams)
      $ curl -fsSL https://packages.microsoft.com/keys/microsoft.asc | sudo gpg --dearmor -o ${DIR_KEYRING}/packages.microsoft.gpg
  - sublimetext
      $ wget -qO - https://download.sublimetext.com/sublimehq-pub.gpg | sudo gpg --dearmor -o ${DIR_GPG}/sublimehq-archive.gpg

+ sources.list.d (*.list)
  - ansible
      deb http://ppa.launchpad.net/ansible/ansible/ubuntu focal main
  - brave-browser
      deb [signed-by=${DIR_KEYRING}/brave-browser.gpg] https://brave-browser-apt-release.s3.brave.com/ stable main
  - chrome
      deb [arch=${ARCH}] https://dl.google.com/linux/chrome/deb/ stable main
  - code
      deb [arch=${ARCH} signed-by=${DIR_KEYRING}/microsoft.gpg] http://packages.microsoft.com/repos/code stable main
  - docker
      deb [arch=${ARCH} signed-by=${DIR_KEYRING}/docker.gpg] https://download.docker.com/linux/debian ${LSB_RELEASE_CODENAME} stable
  - hashicorp (terraform, packer, vault, consul)
      deb [signed-by=${DIR_KEYRING}/hashicorp.gpg] https://apt.releases.hashicorp.com ${LSB_RELEASE_CODENAME} main
  - helm
      deb [arch=${ARCH} signed-by=${DIR_KEYRING}/helm.gpg] https://baltocdn.com/helm/stable/debian/ all main
  - gcloud
      deb [signed-by=${DIR_KEYRING}/google-cloud.gpg] https://packages.cloud.google.com/apt cloud-sdk main
  - kubernetes
      deb [signed-by=${DIR_KEYRING}/kubernetes.gpg] https://apt.kubernetes.io/ kubernetes-xenial main
  - sublimetext
      deb https://download.sublimetext.com/ apt/stable/
  - teams
      deb [signed-by=${DIR_KEYRING}/microsoft.gpg] https://packages.microsoft.com/repos/ms-teams stable main

+ package
  - ansible
  - brave-browser
  - code
  - docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
  - docker-compose
  - google-chrome-stable
  - helm
  - jq
  - kubectl
  - shellcheck
  - snap
  - sublimetext
  - teams
  - terraform

## deb
  - wps

## snap
  - skype

## git repo
  - brew
      $ /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
  - codex-cli
      https://github.com/microsoft/Codex-CLI/blob/main/Installation.md
  - yq
      $ wget https://github.com/mikefarah/yq/releases/latest/download/yq_linux_amd64 -O /usr/bin/yq &&\
    chmod +x /usr/bin/yq

--- CONFIG

_pc_install

--- ACER ASPIRE 5 A514-55-51XE

OS: Debian 11
Default kernel: 5.10
DE: KDE Plasma

## ISSUES
+ with KDE Plasme DE, black screen on startup login screen, no DE
+ log
  $ dmesg --level=err
[    0.337937] pci 0000:00:07.0: DPC: RP PIO log size 0 is invalid
[    1.544938] integrity: Problem loading X.509 certificate -65
[    1.544948] integrity: Problem loading X.509 certificate -65
[    2.267560] i915 0000:00:02.0: firmware: failed to load i915/adlp_dmc_ver2_16.bin (-2)
[    2.267563] firmware_class: See https://wiki.debian.org/Firmware for information about missing firmware
[    2.267567] i915 0000:00:02.0: firmware: failed to load i915/adlp_dmc_ver2_16.bin (-2)
[    2.277183] i915 0000:00:02.0: firmware: failed to load i915/adlp_guc_70.1.1.bin (-2)
[    2.277189] i915 0000:00:02.0: firmware: failed to load i915/adlp_guc_70.1.1.bin (-2)
[    2.277194] i915 0000:00:02.0: firmware: failed to load i915/adlp_guc_69.0.3.bin (-2)
[    2.277199] i915 0000:00:02.0: firmware: failed to load i915/adlp_guc_69.0.3.bin (-2)
[    2.277200] i915 0000:00:02.0: GuC firmware i915/adlp_guc_70.1.1.bin: fetch failed with error -2
[    2.368614] i915 0000:00:02.0: GuC initialization failed -2
[    2.368616] i915 0000:00:02.0: Enabling uc failed (-5)
[    2.368617] i915 0000:00:02.0: Failed to initialize GPU, declaring it wedged!
[    6.918799] uvcvideo 1-7:1.1: Failed to query (129) UVC probe control : 26 (exp. 48).
[    6.918833] uvcvideo 1-7:1.1: Failed to initialize the device (-5).
[    7.257953] bluetooth hci0: firmware: failed to load rtl_bt/rtl8852bu_fw.bin (-2)
[    7.257990] bluetooth hci0: firmware: failed to load rtl_bt/rtl8852bu_fw.bin (-2)
[    7.258014] Bluetooth: hci0: RTL: firmware file rtl_bt/rtl8852bu_fw.bin not found
[    7.507427] sof-audio-pci-intel-tgl 0000:00:1f.3: firmware: failed to load intel/sof/sof-adl.ri (-2)
[    7.507471] sof-audio-pci-intel-tgl 0000:00:1f.3: firmware: failed to load intel/sof/sof-adl.ri (-2)
[    7.507506] sof-audio-pci-intel-tgl 0000:00:1f.3: error: sof firmware file is missing, you might need to
[    7.507538] sof-audio-pci-intel-tgl 0000:00:1f.3:        download it from https://github.com/thesofproject/sof-bin/
[    7.507557] sof-audio-pci-intel-tgl 0000:00:1f.3: error: failed to load DSP firmware -2
[    7.507965] sof-audio-pci-intel-tgl 0000:00:1f.3: error: sof_probe_work failed err: -2
[   11.372617] r8169 0000:2b:00.0: firmware: failed to load rtl_nic/rtl8168h-2.fw (-2)
[   11.373357] r8169 0000:2b:00.0: firmware: failed to load rtl_nic/rtl8168h-2.fw (-2)
[   11.373912] r8169 0000:2b:00.0: Unable to load firmware rtl_nic/rtl8168h-2.fw (-2)

## KERNEL UPGRADE
+ add backport repo to sources.list
    deb http://deb.debian.org/debian bullseye-backports main contrib non-free
    deb-src http://deb.debian.org/debian bullseye-backports main contrib non-free
+ upgrade kernel
  $ apt update
  $ apt-cache policy linux-image-amd64
  $ apt install linux-image-amd64=6.0.12-1~bpo11+1 linux-headers-6.0.0-0.deb11.6-amd64
  $ reboot

## INSTALL DEVICES DRIVERS   
    REQUIREMENTS
      // install firmwares from Backports
        $ apt install -t bullseye-backports firmware-linux firmware-linux-free firmware-linux-nonfree firmware-sof-signed firmware-intel-sound firmware-misc-nonfree firmware-realtek
      // download latest firmware from kernel git repo
        $ git clone https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git /opt/linux-firmware
    
    (Backup existing firmware files if needed)
    
    VGA (Intel Iris Xe Graphics)
    --> Intel Corporation Device 46a8 (rev 0c)
    --> i915
      $ mv /lib/firmware/i915 /lib/firmware/i915_ORIG
      $ cp -avr /opt/linux-firmware/i915 /lib/firmware/
      
    BLUETOOTH (Realtek)
    --> Realtek Bluetooth Radio
    --> rtl_bt
      $ mv /lib/firmware/rtl_bt /lib/firmware/rtl_bt__ORIG
      $ cp -avr /opt/linux-firmware/rtl_bt /lib/firmware/
    
    AUDIO (Intel)
    --> Intel Corporation Device 51c8 (rev 01)
    --> SOF Project
        // Download the SOF firmware project binaries from repo
      $ wget https://github.com/thesofproject/sof-bin/releases/download/v2.2.4/sof-bin-v2.2.4.tar.gz -O - |tar -xz -C /opt/
      $ mv /lib/firmware/intel/sof /lib/firmware/intel/sof_ORIG
      $ mv /lib/firmware/intel/sof-tplg /lib/firmware/intel/sof-tplg_ORIG
      $ mv /lib/firmware/intel/sof-tplg-v1.7 /lib/firmware/intel/sof-tplg-v1.7_ORIG
      $ cd /opt/sof-bin-v2.2.4 && ./install.sh v2.2.4
    
    ETHERNET (Realtek)
    --> Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 15)
    --> r8168
       ... NO ISSUE ...
    
    WIFI (Realtek)
    --> Realtek Semiconductor Co., Ltd. Device b852Realtek Bluetooth Radio
    --> rtw89
      // install requirements
        $ apt install make gcc linux-headers-$(uname -r) build-essential git
      // Download Realtek rtlwifi codes from project repo
          - kernel <6.0 : https://github.com/HRex39/rtl8852be
          - kernel >=6.0 : https://github.com/lwfinger/rtw89
        $ git clone https://github.com/lwfinger/rtw89.git /opt/rtw89
        $ cd /opt/rtw89
        $ make
        $ make install
       // copy new firmwares files from kernel repo
        $ mv /lib/firmware/rtw89 /lib/firmware/rtw89_ORIG
        $ cp -avr linux-firmware/rtw89 /lib/firmware/rtw89
       // unload/reload kernel modules
        $ modprobe -rv rtw_8852ae
        $ modprobe -rv rtw_core
        $ modprobe -v rtw_8852ae
  
    THUNDERBOLT USB (Intel)
    --> Intel Corporation Device 463e (rev 04) (thunderbolt)
    --> thunderbolt
      ... NO ISSUE ..
  
    WEBCAM (ACER)
    --> ACER HD User Facing
      ###
      ### BIG PROBLEM
      ###
      https://www.mail-archive.com/[email protected]/msg494663.html
  // reload kernel config
  $ update-initramfs -u -k all
  $ reboot

_poc

## ELK
+ apm + fleetserver

_principle

‎‎​

_service_saas

## PAYMENT
  - Stripe
  - Adyen

## SHIPPING
  - Chronopost
  - UPS

## TAX
  - Avalara

## MONITORING
  + Data
    - Datadog
  + APM
    - AppDynamics

_to_know

--- MISC
+ eBPF, Cilium
+ observability

--- DATA
+ DBT (Data Build Tools)

--- TERRAFORM
+ workspace

--- ANSIBLE
+ collection

--- GCP
+ service mesh
+ GKE Dataplane V2

--- PROMETHEUS
+ node exporter

agile

I&A: Inspect & Adapt
MMP: Minimum Marketable Product
MVP: Minimum Viable Product
PDCA: Plan Do Check Adjust
ROAM: Resolved Owned Accepted Mitigated
RPO: Recovery Point Objective
RTE: Release Train Engineer
RTO: Recovery Time Objective
WSJF: Weighted Shortest Job First

## retro
  KISS: Keep Improve Start Stop

## Story/stress Points
-> abstract estimation
+ take in account
  - difficulty
  - effort
  - risks
  - doubts/incertitudes
  - inter-dependancies
+ how to use
  - use fibonacci sequence: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233
      >8 -> to cut
  - use t-shirt size: XS, S, M, L, XL, XXL
      >XL -> to cut
  - days/man: 1/2d, 1d, 2d, 3d, 4d, 5d, 6d
      >5d -> to cut

## Planning Poker
-> product backlog refinement (grooming), take story points

## Grooming/refinement --> Product Backlog Refinement
-> review of team's backlog (backlog refinement)

## Extreme Quotation

## Burndown chart

## Cut-Over planning
  Actions planning for a big change of an old technology to a new one


--- MEETING

## DSM (<=15m)
  - what you've done, what you are doing/ will do, if there is an issue?
  - turn by turn
  - no debate, no problem resolution
  - can tell if there is issues/problems -> debate after
(2h Ceremony)

## REVIEW
  + Sprint (<=1h20m)

## PLANNING
  + PI
  + Sprint (<=30m)

## RETRO
  + Sprint (<=10m)

ansible

--- MISC ---

## suppress output of a task
  - task
    no_log: True

--- SPECIAL ENV VARS

ANSIBLE_VERBOSITY=[1-5]
ANSIBLE_DEBUG=[1|0]
    
--- ISSUE ---

## SHORT-SHA miss-interpreted
https://stackoverflow.com/questions/59066160/issue-deploying-to-appengine-flex-from-cloud-build

--- PLUGINS ---

## gcp plugin for ansible

  --> inventory.gcp.yml
plugin: gcp_compute
projects:
  - gcp_project
auth_kind: serviceaccount
service_account_file: '/path/to/service-account.json'

  --> ansible.cfg
[inventory]
enable_plugins = gcp_compute

--- BLOCK ---

- name: Multiple task in a block
  block:
  - name: 1st task
    module:
      param: value
  - name: 2nd task
    module:
      param: value

--- SERVICES ----

- name: Get service facts & check if a service exist
  block:
  - name: Get services facts
    service_facts:
  - name: Check if my_service is installed
    fail:
      msg: my_service is not installed, install it before
    when: ansible_facts.services["my_service.service"] is not defined
    
--- COLLECTION ---

## install collection
  $ ansible-galaxy collection install --collections-path ~/.ansible/collections ansible.posix

  requirements.yml
  ```
    collections:
      - community.general
      - ansible.posix
  ```
  $ ansible-galaxy collection install --force --collections-path /root/.ansible/collections -r requirements.yml

apache

## disable directory listing

  <Directory /var/www/public_html>
      Options -Indexes
  </Directory>
  
 ## force redirect non-www to https://wwww

    RewriteEngine On
    RewriteCond %{HTTP_HOST} !^www\. [NC]
    RewriteRule ^(.*)$ https://www.%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
    
## force redirect http|www|non-www to https|non-www
    RewriteEngine On
    RewriteCond %{SERVER_NAME} =DOMAIN.COM [OR]
    RewriteCond %{SERVER_NAME} =WWW.DOMAIN.COM
    RewriteRule ^ https://DOMAIN.COM%{REQUEST_URI} [END,NE,R=permanent]

architecture

Domain Driven Design (DDD)
Loose coupling and API-driven architecture
Cloud-native architecture
Microservices and containerization
Serverless architecture
Strangler pattern

cloud

## Move to cloud strategies

  - Rehost/ Lift and Shift (IaaS)
      rehost application in another hardware environment without changing architecture.
  - Refactor (PaaS)
      move apps on a cloud infrastructure
  - Rebuild
      throw out the code for an existing app and rearchitect it
  - Replace (SaaS)
      discard existing application set and adopt commercial software delivered as a service

devOps

--- deployment 

## deployment pattern
+ canary
+ dark launch
+ blue/green

dns

## reverse lookup
  $ dig -x IP_ADDRESS

docker

--- BUILD ---

## build image
    $ docker build -t IMAGE_NAME:TAG .
    $ docker build -t IMAGE_NAME:TAG -f /PATH/TO/DOCKERFILE

--- DOCKER-COMPOSE ---

## ERROR: Error creating container: UnixHTTPConnectionPool(host='localhost', port=None): Read timed out. (read timeout=60)
    increase timeout
  $ COMPOSE_HTTP_TIMEOUT=200 docker-compose up

--- FILE ---

## copy file
+ host to container
    $ docker cp FILE_ON_HOST CONTAINER_ID:FILE
+ container to host
    $ docker cp CONTAINER_ID:FILE FILE_ON_HOST

--- IMAGE ---

## rename image
    $ docker tag CURRENT_IMAGE_NAME:TAG NEW_IMAGE_NAME:TAG
    
--- RUN ---

## run container
    $ docker run --name CONTAINER_NAME -p LOCAL_PORT:CONTAINER_PORT -e ENV_VAR=VALUE IMAGE:TAG

ftp

--- pure-ftpd ---

## Change password
  $ sudo pure-pw passwd FTP_USER
  $ sudo pure-pw mkdb

gcp

--- HISTORY ---

Basic principle:
  - collect data
  - stock data
  - process data with compute power

Main type of compute power:
  - network
  - storage
  - compute engine

 ## Google technology timeline
 2002: GFS (Filesystem/ OpenSource: HDFS)
 2004: MapReduce (Filesystem over datacenter)
 2006: BigTable (NoSQL/ OpenSource: HBase)
 2006: Borg (Container orchestrator/ OpenSource: Kubernetes)
 2008: Dremel (Datawarehouse/ Origin of BigQuery)
 2010: Colossus
 2012: Flumejava
 2013: Spanner
 2015: Kubernetes
 2016: Tensorflow

## GCP products categories
  + Large public, devices & productivity/collaboration/communication
      -> Gmail, Drive, Android
  + Legacy integrations (expose API, connect business platform)
      -> front app, apigee, vision/language API
  + Core apps (accelerate app delivery)
      -> app dev & management, AppEngine, ContainerEngine
  + Data in silos (EDW, Hadoop)
      -> Data analysis, ML, BigQuery, Dataflow
  + Private data center (Virtualization) (full managed operations)
      -> infrastructure, compute/container, storage, network

## Cloud computing services
---
  + Compute
      - Compute Engine            |Virtual server
      - Kubernetes Engine         |Container orchestrator cluster
      - Cloud Run                 |Container serverless
      - App Engine                |Application runner
      - Cloud Functions           |Simple code runner
  + Networking
      - Cloud Virtual Network
      - Cloud interconnect
      - Cloud DNS
      - Load Balancing
      - Cloud CDN
  + Big Data
      - BigQuery                  |stock large data in database
      - Cloud Pub/Sub             |async messaging bus, ~Kafka
      - Cloud Dataflow            |transform large data
      - Cloud Dataproc            |data science
      - Cloud Datalab             |data science
  + Machine Learning
      - Cloud Machine Learning    |TPU
      - Vision API
      - Speech API
      - Translate API
      - Natural Language API
  + Storage
      - Cloud Storage             |large object storage
      - Cloud SQL                 |relational database
      - Cloud Spanner             |globally distributed/scalable sql/transaction db
      - Cloud Datastore           |NoSQL database
      - Cloud Bigtable            |high-performance NoSQL database (for ML)
  + Database
  + Analytics
  + AI
----
  + Security
  + Tooling
  + API

--- MISC ---

## filter

  Get only a value
  -> internal IP
    $ gcloud compute instances list --filter="name~'${NAME}' status=RUNNING" --format="value(networkInterfaces[0].networkIP)"
  -> public IP
    $ gcloud compute instances list --filter="name~'${NAME}' status=RUNNING" --format="value(networkInterfaces[0].accessConfigs[0].natIP)"

  In a formatted table (box) with sort
    $ gcloud compute instances list --format="table[box](name,creationTimestamp:sort=1,status,metadata.items.version,metadata.items.sha1,INTERNAL_IP)" --filter="name~'hylo' status=RUNNING"

  Get according to datetime (creationTimestamp)
  --> https://cloud.google.com/sdk/gcloud/reference/topic/datetimes
    $ gcloud *** list --filter="creationTimestamp<=-pXyYmZdAm"
    -p: beyond
    +p: from now

## get startupscript log via instance serial port
  $ gcloud compute instances get-serial-port-output INSTANCE --zone=ZONE  |awk '/GCEMetadataScripts/{print substr($0, index($0, $9))}'

--- ENVIRONMENT VARIABLE

Region:               $REGION
Project ID:           $PROJECT_ID
Project number:       $PROJECT_NUMBER
Zone:                 $ZONE
Service Account:      $SERVICE_ACCOUNT
Service Account mail: $SERVICE_ACCOUNT_EMAIL

--- PROJECT ---

## usage
  + Global ressources collection/organization
      - track resource/quota usage
      - enable/disable service/API
      - control permissions/credentials
      - set billing account (can be associated with one/more projects)
      - any services is associated with one and only project
  + isolation between ressources
      - explicit trust across project can be created

## GCP ressources hierarchy level
--> https://cloud.google.com/blog/products/gcp/mapping-your-organization-with-the-Google-Cloud-Platform-resource-hierarchy
[ORG]
                    {Company}
[FOLDERS]
          (Dept1)               (Dept2)   (SharedInfra)
    <TeamA>      <TeamB>
            "Product1"   "Product2"
[PROJECTS]
        'ProjectA' 'Project2'
[RESSOURCES]
        -VM -storage

## set default region/zone
  $ gcloud compute project-info add-metadata --metadata google-compute-default-region=REGION,google-compute-default-zone=ZONE

--- IAM ---

## get role/permissions of a service account
  $ gcloud projects get-iam-policy PROJECT_ID --flatten="bindings[].members" --format='table(bindings.role)' --filter="bindings.members:SERVICE_ACCOUNT_EMAIL"
  $ gcloud asset search-all-iam-policies --query='policy:"serviceAccount:SERVICE_ACCOUNT_EMAIL"'

## get Cloud Storage service agent account
  $ gcloud storage service-agent --project=PROJECT_ID
  or
  $ gsutil kms serviceaccount -p PROJECT_ID

## List of all default Service Accounts
  - App Engine: [email protected]
  - Compute Engine: [email protected]
  - Cloud Functions: [email protected]
  - Cloud Run (fully managed): [email protected]
  - Cloud Build: [email protected]
  - Google Kubernetes Engine (GKE): [email protected]
  - AI Platform: [email protected]
  - Dataprep: [email protected]
  - Dataflow: PROJECT_NUMBER@dataflow-service-producer-prod.iam.gserviceaccount.com
  - BigQuery Data Transfer: [email protected]
  - Pub/Sub: [email protected]

--- SECRET MANAGER ---

## show secret
  $ gcloud secrets versions access latest --secret SECRET_NAME --project PROJECT_NAME

--- GOOGLE STORAGE ---

## mount bucket to instance dir
  $ gcsfuse -o allow_other,nonempty --file-mode 755 --dir-mode 755 --gid XYZ --uid XYZ --key-file /PATH/TO/KEY.json BUCKET_NAME /MOUNT/POINT

  in fstab:
  BBUCKET_NAME /MOUNT/POINT gcsfuse rw,noauto,user,key_file=/PATH/TO/KEY.json

  unmount:
  $ fusermount -u /MOUNT/POINT
  or
  $ sudo umount /MOUNT/POINT

git

--- MISC ---

## execute dry-run command
  $ git cmd --dry-run

## remove tracked dir/file on remote but keep on local
  $ git rm --cached <file-name>
  $ git rm -r --cached <folder-name>git checkout -b subbranch_of_b1 branch1

## prevent git from detecting changes in some files
  $ git update-index --assume-unchanged

## get branch name via cmd
  $ LONG_SHA=$(git rev-parse HEAD)
  $ BRANCH_NAME=$(sed -nE "/$LONG_SHA/s/.*refs\/heads\/(.*)/\1/p" <<< "$(git ls-remote -q)")

## set remote URL
  SSH
  $ git remote set-url origin git@DOMAIN:PROJECT/REPOSITORY.git
  HTTPS
  $ git remote set-url origin https://DOMAIN/PROJECT/REPOSITORY.git

## set pre-commit
  -> https://github.com/pre-commit/pre-commit
  
## BISECT: debug commit by commit
  $ git bisect start
      if bad
        $ git bisect bad
      if good
        $ git bisect good
   $ git bisect run
   $ git bisect log
   $ git bisect skip
   
--- ISSUE

## Gitlab Token changed, reload local repo with new token
"remote: HTTP Basic: Access denied. The provided password or token is incorrect or your account has 2FA enabled and you must use a personal access token instead of a password. See https://gitlabee.dt.renault.com/help/topics/git/troubleshooting_git#error-on-git-fetch-http-basic-access-denied
fatal: Authentication failed for..."
  $ git remote set-url origin https://USER:GITLAB_TOKEN@GITLAB_URL/REPO.git

--- CONFIG ---

## enable color
  $ git config --global color.ui true

--- COMMIT ---

## verify and select commits
  $ git add -p

## undo git add
  $ git reset

## ammend to the previous commit
  
  Commit without edit message 
  $ git commit --amend --no-edit
  
  Change commit message in previous commits
  $ git rebase -i HEAD~n
  --> reword SHA1
  $ git commit --ammend -m "NEW MESSAGE"

## change author of commit
  Set the correct author for current Git repo then
  $ git rebase SRC_BRANCH --exec "git commit --amend --reset-author --no-edit"
  or
  $ git rebase --onto HEAD~N --exec "git commit --amend --reset-author --no-edit" HEAD~N

## revert file to a state from other branch
  $ git checkout BRANCH -- PATH/TO/FILE

## get long sha1 of head
  $ git rev-parse HEAD

## look for branches containing a commit
  $ git branch (--remote) --contains COMMIT_SHA

## commit format
  + Default format
      TYPE(SCOPE): SUBJECT
      OPTIONAL BODY
      OPTIONAL FOOTER
  + Merge commit
      Merge branch 'BRANCH_NAME'
  + Type
      - feat: adds a new feature
      - fix: fixes a bug
      - refactor: rewrite/restructure code, however does not change any behaviour
      - perf: special refactor commits, that improve performance
      - style: do not affect the meaning (white-space, formatting, missing semi-colons, etc)
      - test: add missing tests or correcting existing tests
      - docs: affect documentation only
      - build: affect build components like build tool, ci pipeline, dependencies, project version, ...
      - ops: affect operational components like infrastructure, deployment, backup, recovery, ...
      - chore: miscellaneous commits e.g. modifying .gitignore
  + Breaking Changes Indicator "!"
      TYPE(SCOPE)!: SUBJECT

--- TAG ---

$ git tag TAG BRANCH
$ git push origin TAG

## merge tag to branch
  $ git checkout BRANCH
  $ git merge vTAG

--- FIXUP ---

## fixup anterior commit
  $ git commit --fixup=SHA1
  $ git rebase -i --autosquash SHA1~1

--- BRANCH ---

## create branch from another branch
  $ git checkout branch_orig
  $ git checkout -b feature/branch_dest branch_orig

## diff/compare branches
  $ git diff BRANCHE1..BRANCHE2

## rename branch
  $ git branch -m NEW_NAME
  $ git push origin :OLD_NAME NEW_NAME
  $ git push origin -u NEW_NAME

--- REBASE ---

## rebase feat branch from an origin branch
  $ git rebase -i master

--- RESTORE ---

## restore file to a commit
  $ git checkout COMMID_ID -- FILE

## restore file to a branch
  $ git restore --source origin/BRANCH FILE

--- CHERRY-PICK ---

## cherry pick commit from other branch
  $ git checkout TARGET_BRANCH
  $ git cherry-pick SHA1

--- LOG ---

## log of single file
  $ git glog --follow -p PATH/TO/FILE

## log overiew of all commits and changes
  $ git log --patch
  
## REFLOG (reference logger) log all commands
  $ git reglog show BRANCH

--- MERGE ---

## manual merge local/origin branch to master
  Fetch and check out the branch (create it on local if not exist)
    $ git fetch origin
    $ git checkout -b "feat/MY_BRNACH" "origin/feat/MY_BRANCH"
  Review the changes locally
  Merge the branch and fix any conflicts that come up
    $ git fetch origin
    $ git checkout "master"
    $ git merge --no-ff "feat/MY_BRANCH"
  Push
    $ git push origin "master"

--- RESET ---

## reset to origin branch
  $ git reset --hard origin/BRANCH

--- STASH ----

## stash workflow
  Save
  $ git stash save
  or
  git stash save "WIP MESSAGE"

  Include untracked files
  $ git stash save --include-untracked

  List
  $ git stash list

  Show desc
  $ git stash show stash@{0}

  Get stashed work (and delete ref)
  $ git stash pop
  or
  $ git stash pop stash@{0}

  Get but don't delete ref
  $ git stash apply

--- CLEAN ---

## clean repo directory, remove untracked files
  $ git clean
    -n: dry-run
    -f: force
    -i: interactive
    -d: directory+files

gitlab

------ GITLAB-CI ------

## scheduled job
  ---
  JOB:on-schedule:
  stage: STAGE
  variables:
    VARS: VALUE
  script:
    - CMD
  only:
    - schedules
  ---
    
## templating bloc
  ---
  .TEMPLATE_NAME
    bloc:
      key: value
      
  JOB:
    extend:
      - .TEMPLATE_NAME
  ---

http_status_code

## 1xx INFORMATIONAL
    100 - Continue - Client should continue with request.
    101 - Switching Protocols - Server is switching protocols.
    102 - Processing - Server has received and is processing the request.
    103 - Processing - Server has received and is processing the request.
    122 - Request-uri too long - URI is longer than a maximum of 2083 characters.

## 2xx SUCCESS
    200 - Ok - The request was fulfilled.
    201 - Created - Following a POST command, this indicates success, but the textual part of the response line indicates the URI by which the newly created document should be known.
    202 - Accepted - The request has been accepted for processing, but the processing has not been completed. The request may or may not eventually be acted upon, as it may be disallowed when processing actually takes place. there is no facility for status returns from asynchronous operations such as this.
    203 - Partial Information - When received in the response to a GET command, this indicates that the returned metainformation is not a definitive set of the object from a server with a copy of the object, but is from a private overlaid web. This may include annotation information about the object, for example.
    204 - No Response - Server has received the request but there is no information to send back, and the client should stay in the same document view. This is mainly to allow input for scripts without changing the document at the same time.
    205 - Reset Content - Request processed, no content returned, reset document view.
    206 - Partial Content - partial resource return due to request header.
    207 - Multi-Status - XML, can contain multiple separate responses.
    208 - Already Reported - results previously returned.
    226 - Im Used - request fulfilled, reponse is instance-manipulations.

## 3xx REDIRECTION
    301 - Moved - The data requested has been assigned a new URI, the change is permanent. (N.B. this is an optimisation, which must, pragmatically, be included in this definition. Browsers with link editing capabiliy should automatically relink to the new reference, where possible)
    302 - Found - The data requested actually resides under a different URL, however, the redirection may be altered on occasion (when making links to these kinds of document, the browser should default to using the Udi of the redirection document, but have the option of linking to the final document) as for "Forward".
    303 - Method - Like the found response, this suggests that the client go try another network address. In this case, a different method may be used too, rather than GET.
    304 - Not Modified - If the client has done a conditional GET and access is allowed, but the document has not been modified since the date and time specified in If-Modified-Since field, the server responds with a 304 status code and does not send the document body to the client.
    305 - Use Proxy - Content located elsewhere, retrieve from there.
    306 - Switch Proxy - Subsequent requests should use the specified proxy.
    307 - Temporary Redirect - Connect again to different URI as provided.
    308 - Permanent Redirect - Connect again to a different URI using the same method.

## 4xx CLIENT SIDE ERRORS
    400 - Bad Request - The request had bad syntax or was inherently impossible to be satisfied.
    401 - Unauthorized - The parameter to this message gives a specification of authorization schemes which are acceptable. The client should retry the request with a suitable Authorization header.
    402 - Payment Required - The parameter to this message gives a specification of charging schemes acceptable. The client may retry the request with a suitable ChargeTo header.
    403 - Forbidden - The request is for something forbidden. Authorization will not help.
    404 - Not Found - The server has not found anything matching the URI given.
    405 - Method Not Allowed - Request method not supported by that resource.
    406 - Not Acceptable - Content not acceptable according to the Accept headers.
    407 - Proxy Authentication Required - Client must first authenticate itself with the proxy.
    408 - Request Timeout - Server timed out waiting for the request.
    409 - Conflict - Request could not be processed because of conflict.
    410 - Gone - Resource is no longer available and will not be available again.
    411 - Length Required - Request did not specify the length of its content.
    412 - Precondition Failed - Server does not meet request preconditions.
    413 - Request Entity Too Large - Request is larger than the server is willing or able to process.
    414 - Request URI Too Large - URI provided was too long for the server to process.
    415 - Unsupported Media Type - Server does not support media type.
    416 - Requested Rage Not Satisfiable - Client has asked for unprovidable portion of the file.
    417 - Expectation Failed - Server cannot meet requirements of Expect request-header field.
    418 - I'm a teapot - I'm a teapot.
    420 - Enhance Your Calm - Twitter rate limiting.
    421 - Misdirected Request - Server is not able to produce a response.
    422 - Unprocessable Entity - Request unable to be followed due to semantic errors.
    423 - Locked - Resource that is being accessed is locked.
    424 - Failed Dependency - Request failed due to failure of a previous request.
    426 - Upgrade Required - Client should switch to a different protocol.
    428 - Precondition Required - Origin server requires the request to be conditional.
    429 - Too Many Requests - User has sent too many requests in a given amount of time.
    431 - Request Header Fields Too Large - Server is unwilling to process the request.
    444 - No Response - Server returns no information and closes the connection.
    449 - Retry With - Request should be retried after performing action.
    450 - Blocked By Windows Parental Controls - Windows Parental Controls blocking access to webpage.
    451 - Wrong Exchange Server - The server cannot reach the client's mailbox.
    499 - Client Closed Request - Connection closed by client while HTTP server is processing.

## 5xx SERVER SIDE ERROR
    500 - Internal Error - The server encountered an unexpected condition which prevented it from fulfilling the request.
    501 - Not Implemented - The server does not support the facility required.
    502 - Service temporarily overloaded - The server cannot process the request due to a high load (whether HTTP servicing or other requests). The implication is that this is a temporary condition which maybe alleviated at other times.
    503 - Gateway timeout - This is equivalent to Internal Error 500, but in the case of a server which is in turn accessing some other service, this indicates that the respose from the other service did not return within a time that the gateway was prepared to wait. As from the point of view of the clientand the HTTP transaction the other service is hidden within the server, this maybe treated identically to Internal error 500, but has more diagnostic value.
    504 - Gateway Timeout - Gateway did not receive response from upstream server.
    505 - Http Version Not Supported - Server does not support the HTTP protocol version.
    506 - Variant Also Negotiates - Content negotiation for the request results in a circular reference.
    507 - Insufficient Storage - Server is unable to store the representation.
    508 - Loop Detected - Server detected an infinite loop while processing the request.
    509 - Bandwidth Limit Exceeded - Bandwidth limit exceeded.
    510 - Not Extended - Further extensions to the request are required.
    511 - Network Authentication Required - Client needs to authenticate to gain network access.
    598 - Network Read Timeout Error - Network read timeout behind the proxy.
    599 - Network Connect Timeout Error - Network connect timeout behind the proxy.

jinja

--> https://jinja.palletsprojects.com/en/3.0.x/templates/#jinja-filters.indent

## condition
  {% if VAR == VALUE %} or {% if VAR is defined %}
  PUT THIS
  {% endif %}

## indent multiline var
   vars:
    level_1:
      level_2: |
        - list_1
        - list_2
    ---
    main:
    - this_is_a_list:
        {{ level_1.level_2 | indent( width=4, first=False) }}
    ---
    
  

kubernetes

--- DOC ---

+ node: physical/virtual server where run k8s (master, workers)
+ pod: instance, set of containers
+ service: make pod communication
    clusterIP
    nodePort
+ volume: stockage for pods, shared by containers
    persistent
    nonPersistent
+ deployment: manage deployment
+ namespace: subset of cluster, isolating set of service


--- MISC ---

## run shell on container
  $ kubectl exec --stdin --tty CONTAINER -- /bin/bash

## restart an workload/deployment
  $ kubectl rollout restart deployment DEPLOYMENT
  
--- SECRET ----

## declaration
apiVersion: v1
kind: Secret
metadata:
  name: SECRET-NAME
Data:
  KEY1: VALUE
  KEY2: VALUE

## usage
spec:
  containers:
    - name: NAME
      image: IMAGE
      env:
        - name: VAR_NAME
          valueFrom:
            secretKeyRef:
              name: SECRET-NAME
              key: KEY_NAME


## type
  - Data: base64
  - stringData: plain text
  
--- ISSUE ---

## pv stuck terminating
  $ kubectl patch pv PV_NAME -p '{"metadata":{"finalizers":null}}'
  or
  $ kubectl edit pv PV_NAME
    DELETE -> finalizers: - kubernetes.io/pv-protection
  
  $ kubectl delete pv PV_NAME --grace-period=0 --force 

licences

--- OPEN SOURCE ---

## Apache

## Artistic License

## BSD

## Common Development and Distribution License (CDDL)

## CREATIVE COMMONS (CC)
  Licenses offering creators flexibility in sharing their work with the world while allowing them to choose the level of control they want over how their work is used, attributed, and shared
  https://creativecommons.org/share-your-work/cclicenses/

  + CC BY (Attribution):
      allows others to distribute, remix, adapt, and build upon your work, even for commercial purposes, as long as they give you appropriate credit.
      This is the most permissive CC license.
  + CC BY-SA (Attribution-ShareAlike):
      Similar to CC BY but requires any derivative works to be licensed under the same terms,
      ensuring that subsequent creations remain open and shareable.
  + CC BY-NC (Attribution-NonCommercial):
      permits others to use and modify your work for non-commercial purposes, as long as they provide proper attribution.
      Commercial use is not allowed.
  + CC BY-ND (Attribution-NoDerivatives):
      others can reuse your work for any purpose, even commercially, but they can't make any modifications or derivative works.
      They must credit you as the creator.
  + CC BY-NC-SA (Attribution-NonCommercial-ShareAlike):
      combines the requirements of CC BY-NC and CC BY-SA,
      allowing for non-commercial use and requiring derivative works to be licensed under the same terms.
  + CC BY-NC-ND (Attribution-NonCommercial-NoDerivatives):
      the most restrictive CC license.
      allows others to download your work and share it with proper attribution, but they can't change it or use it for commercial purposes.
  + CC 0 (No Rights Reserved):
      not technically a license but a dedication to the public domain.
      waive all your copyright and related rights, effectively placing the work in the public domain

## Eclipse Public License (EPL)

## GNU General Public License (GPL):

## GNU Lesser General Public License (LGPL)

## MIT

## Mozilla Public License (MPL)

--- CLOSED SOURCE ---

--- COMMERCIAL ---

mysql

--- MISC ---

## error!
>> 1418 (HY000) at line 10185: This function has none of DETERMINISTIC, NO SQL, or READS SQL DATA in its declaration and binary logging is enabled (you *might* want to use the less safe log_bin_trust_function_creators variable)

  1- Execute:
    SET GLOBAL log_bin_trust_function_creators = 1;
  or
  2- Add to mysql.ini config file:
    log_bin_trust_function_creators = 1;
    
 ## show mysqld startup config
  > SHOW VARIABLES;
  > SHOW VARIABLES LIKE '%innodb_log_buffer_size%';

--- MYSQL DUMP ---

## error mysqldump!
>> Unknown table 'COLUMN_STATISTICS' in information_schema

  Flag "COLUMN_STATISTICS" is enabled by default in mysqldump 8
  
  Run mysqldump with additional parameter:
  $ mysqldump --column-statistics=0
  
  Make change permanent:
  --> ~/.my.cnf
    [mysqldump]
    column-statistics=0
 
 --- TRANSACTION MODE ---
 
 ## start
  START TRANSACTION;
  CMD_1;
  CMD_N;
  ...
 ## commit
  COMMIT;
 ## rollback
  ROLLBACK;
 

network

--- MISC ---

## tcpdump
  show interface
        $ tcpdump -D
  on specific interface
        $ tcpdump -i INTERFACE
  on specific port
        $ tcpdump port PORT -i INTERFACE
  capture only N number of packets
        $ tcpdump -c N -i INTERFACE
  display captured packets in ASCII
        $ tcpdump -A -i INTERFACE
  display Captured Packets in HEX and ASCII
        $ tcpdump -XX -i INTERFACE
  capture and save packets in a file
        $ tcpdump -w FILE.pcap -i INTERFACE
  read captured packets file
        $ tcpdump -r FILE.pcap
  capture IP address packets
        $ tcpdump -n -i INTERFACE
  capture only TCP Packets
        $ tcpdump -i INTERFACE tcp
        
## netcat
  + Transfert file
      --> on receiver
      $ nc -l -p PORT > FILE
      --> on sender
      $ nc -w 3 DEST_IP PORT < FILE

  + Compress file & transfert
      --> on receiver
      $ nc -l -p PORT | uncompress -c | tar xvfp -
      --> on sender
      $ tar cfp - DIR | compress -c | nc -w 3 DEST_IP PORT

  + Reverse shell with root prilileges
      --> target
        $ ncat -l PORT -e /bin/bash -v -w 5000ms
      --> source
        $ ncat 127.0.0.1 PORT -v

  + Test open port
      $ nc -vn IP PORT
      $ nc -vnz -w IP RANGE-IP
      
--- WIFI ---

## scan wifi
  $ iwlist INTERFACE scan

## connect to wifi via cli
  $ 
  $ nmcli dev wifi connect SSID password PASSWORD
  
--- IP ADDRESS ---

## address classes
  A: 0.0.0.0 - 126.255.255.255 (private: 10.0.0.0 - 10.255.255.255)
  B: 128.0.0.0 - 191.255.255.255 (private: 172.16.0.0 - 172.31.255.255)
  C: 192.0.0.0 - 223.255.255.255 (private: 192.168.1.0 - 192.168.255.255)
  D: 224.0.0.0 - 239.255.255.255 (for multicast)
  E: 240.0.0.0 - 255.255.255.255 (reserved by IETF)
  
  127.0.0.0: for local loop
  0.0.0.0: default route

-- IPV6 ---

## disable IPv6
  $ sudo cat > /etc/sysctl.d/70-disable-ipv6.conf
      net.ipv6.conf.all.disable_ipv6 = 1
  $ sudo sysctl -p -f /etc/sysctl.d/70-disable-ipv6.conf

nginx

--- MISC ---

## misc
  Check syntax
  $ nginx -t
  Dump all config
  $ nginx -T
  Reload conf
  $ nginx -s reload
  
--- BUFFER ---

## tuning buffer
ERROR: upstream sent too big header while reading response header from upstream
--> https://www.getpagespeed.com/server-setup/nginx/tuning-proxy_buffer_size-in-nginx
  proxy_busy_buffers_size   24k;
  proxy_buffers   64 4k;
  proxy_buffer_size   16k;

npm

## error: ngrok - install failed [Error: EACCES: permission denied
  --> https://github.com/bubenshchykov/ngrok#usage
  $ npm install --unsafe-perm -g ngrok

packer

--- MISC ---

## Do not remove instance when packer build fails
  $ packer build -on-error=abort APP.json

parser

--- JQ ---

## get all paths
  $ jq -r '[paths | join(".")]' FILE.json
  
## get all paths and its value
  $ jq --stream -r 'select(.[1]|scalars!=null) | "\(.[0]|join(".")): \(.[1]|tojson)"' FILE.json
  $ jq -r 'paths(scalars) as $p  | [ ( [ $p[] | tostring ] | join(".") ), ( getpath($p) | tojson )] | join(": ")' FILE.json

safe

FORMATION

RTE:
  Release Train Engineer
STE:
  Solution Train Engineer

shell

--- MISC ---

## copy/move all files except some
  $ cp|mv !(FILE_1|FILE_N) DEST/

## list all functions defined in shell
  See list
  $ declare -F
  $ compgen -A function
  See list of function + aliases
  $ compgen -a -A function
  See list with content
  $ declare -f
  See content of a fuction
  $ type FUNCTION

## redirect cmd output/errors to file
  $ CMD --params 2>&1 | tee /path/to/file.log

## chaining command with list output
  $ CMD_1_OUTPUT_LIST | xargs -I {}  CMD_2_PROCESS_EVERY_ITEM_OF_THE_LIST

## update-alternatives

  Install
  $ update-alternatives --install /path/to/link name /path/to/binary [priority]
  $ update-alternatives --install /usr/bin/python python /usr/bin/python2.7 2
  $ update-alternatives --install /usr/bin/python python /usr/bin/python3.7 3

  Select
  $ update-alternatives --config python

## XML lint, formatting
  in package: libxml2-utils
  $ xmllint --format UGLY.xml --output FORMATTED.xml

## sudo without password
  $ visudo
    %sudo   ALL=(ALL) NOPASSWD:ALL

## autocompletion
  --> in bashrc
    if [ -f /etc/bash_completion ]; then
      . /etc/bash_completion
    fi

## add timestamp to bash_history
  $ export HISTTIMEFORMAT="%F %T "
  # cat > /etc/profile.d/timestamp-history.sh
      HISTTIMEFORMAT="%F %T "


--- ARCHIVE ---

## zip multiple files in one archive
  $ zip ARCHIVE.zip FILE1 FILE2 FILEN $FILE*
  $ zip -r ARCHIVE.zip DIR/

## zip/unzip with password
  $ zip -e -P "PASSWORD" FILE FILE.zip
  $ zip -e -P "PASSWORD" FILE FILE.zip

## list file in zip
  $ unzip -l oc-4.13.0.zip "*/"
  $ zipinfo -1 oc-4.13.0.zip "*/"

--- SERVICE ---

## /etc/init.d
  $ sudo vim /etc/init.d/SERVICE
  --> https://gist.githubusercontent.com/miromannino/a17f3e6f3fdcb4d94a1f/raw/e9bc2a8179860701224be896b420a635454dd3bd/service.sh
  $ sudo chmod a+x /etc/init.d/SERVICE
  $ sudo update-rc.d SERVICE defaults

--- LOGIN MESSAGE

## MOTD: login banner message for system-wide announcements
  /etc/motd

## HUSHLOGIN: login banner message for individual user (suppress motd)
  ~/.hushlogin

--- HARDWARE ---

## check hardware device informations
  List all
  $ lspci -s
    ID Type: Fabricant, Version
    0000:2a:00.0 Network controller: Realtek Semiconductor Co., Ltd. Device b852

  Show details info about a device
  $ lspci -v -s ID

--- FILE ---

## delete line from N file to the end
  $ sed -i 'N,$d' FILE

--- DESKTOP MANAGER ---

## change wallpaper
  KDE
  $ qdbus org.kde.plasmashell /PlasmaShell org.kde.PlasmaShell.evaluateScript 'var allDesktops = desktops();print (allDesktops);for (i=0;i<allDesktops.length;i++) {d = allDesktops[i];d.wallpaperPlugin = "org.kde.image";d.currentConfigGroup = Array("Wallpaper", "org.kde.image", "General");d.writeConfig("Image", "file:///PATH/TO/FILE.png")}'

--- SERVICES ---

## check service journalctl
  $ journalctl -u SERVICE.service

--- PACKAGE MANAGER ---

## check package who provided a CMD/file
  $ dpkg -S $(which CMD)
  $ yum whatprovides $(which CMD)
  $ dnf provides $(which CMD)
  $ rpm -qf $(which CMD

## snap
  $ snap install PACKAGE
  $ snap info PACKAGE
  $ snap refresh PACKAGE --channel=X.Y/stable --classic

## hold a specific version of package
  $ apt-mark hold PACKAGE-x.y.z
  or
  $ vim /etc/apt/preferences.d/PACKAGE
      Package: linux-image-4.19.0-6-amd64
      Pin: version 4.19.81-2+deb10u1
      Pin-Priority: -1

--- SSH ---

## ssh config (.ssh/config)
  + keep connection alive
      TCPKeepAlive yes
      ServerAliveInterval 30
  + use private key
      IdentityFile ~/.ssh/key.openssh
  + log level
      Loglevel QUIET|FATAL|ERROR|VERBOSE|DEBUG|DEBUG1|DEBUG2|DEBUG3:-INFO

## verify ssh keypair match
  $ ssh-keygen -y -e -f <private_key>
  compare with <public_key>

## proxy tcp tunnel over ssh
  SSH only
  $ /usr/bin/ssh -o "ServerAliveInterval 30" -o "ServerAliveCountMax 3" -NL [LOCAL_PORT]:127.0.0.1:[REMOTE_PORT] [REMOTE_USER]@[REMOTE_ADRESS] -p [REMOTE_SSH_PORT]
  AUTOSSH
  $ /usr/bin/autossh -M 0 -o "ServerAliveInterval 30" -o "ServerAliveCountMax 3" -NL [LOCAL_PORT]:127.0.0.1:[REMOTE_PORT] [REMOTE_USER]@[REMOTE_ADRESS] -p [REMOTE_SSH_PORT]

  ssh tunnel for mysql
  $ ssh -N -L LOCAL_PORT:REMOTE_INTERFACE_IP:REMOTE_PORT USER@REMOTE_IP

## disable password auth for specific users/group
  --> /etc/ssh/sshd_config
  "
  #PasswordAuthentication yes
  Match [User|Group|Adress] [USER]
    PasswordAuthentication no
  "
  [USER]: - user1,user2
          - group1,group2
          - !root
          - 192.168.1.2,192.168.12.*
          - hostname
          -

## Without host key verification
  $ ssh -o "UserKnownHostsFile=/dev/null" -o "StrictHostKeyChecking=no" user@host

## save key passphrase (avoid prompt)
  $ eval `ssh-agent -s`
  $ ssh-add ~/.ssh/PRIVATE_KEY

 --- PDF ---

 ## combine pdf
  $ pdfunite file1.pdf file2.pdf fileN.pdf output.pdf

 --- USER/GROUP ---

 ## add system user
  $ sudo adduser --group GROUP --system USER
  ~$ sudo useradd -g GROUP -d /dev/null -s /usr/sbin/nologin USER

 ## delete user from group
  $ gpasswd -d USER GROUP

 ## run as other user
  $ runuser -l USER -c 'cmd args'
  ~$ runuser -u USER -- cmd args
  ~$ su - USER -c "cmd args"
  ~$ sudo -u USER cmd args

 --- WGET ---

 ## pass user/pwd
  $ wget --http-user USER --http-password PWD  URL

 --- LINK ---

 ## change symbok link target
  $ readlink -v LINK
  $ ln -sfn /PATH/TO/NEW/FILE LINK_NAME

 --- XARGS ---

 ## loop with xargs
  $ $(CMD TO GET A LIST) |xargs -I {} $(CMD TO LOOP ON THE LIST) {}

 --- OPENSSL ---

[GET INFO]
## check CSR (Certificate Signing Request)
  $ openssl req -text -noout -verify -in CSR.csr

## check Private Key
  $ openssl rsa -in privateKey.key -check

## check PEM formatted certificate
  $ openssl x509 -text -noout -in cert.{pem|crt}

## check DER formatted certificate
  $ openssl x509 -in MYCERT.der -inform der -text

## check PKCS#12 file (.pfx or .p12)
  $ openssl pkcs12 -info -in keyStore.p12

## check certificate from URL
  $ openssl s_client -showcerts -connect [URL]:443

## check expiration date
  $ echo | openssl s_client -connect example.com:443 -servername example.com 2>/dev/null | openssl x509 -noout -dates

## Check all SAN (Subject Alternative Name) in the certificate
  $ openssl s_client -connect website.com:443 | openssl x509 -noout -text | grep DNS:

## check if cert & private key match
  $ openssl x509 -modulus -noout -in CERT.crt |md5sum
  $ openssl rsa -modulus -noout -in PRIV.priv |md5sum

[GENERATE CERTIFICATE]
## generate Private Key and Certificate Signing Request
  $ openssl req -out CSR.csr -new -newkey rsa:2048 -nodes -keyout privateKey.key

## generate self-signed certificate
  $ openssl req -x509 -sha256 -nodes -days 365 -newkey rsa:2048 -keyout privateKey.key -out certificate.crt

## generate CSR for existing private key
  $ openssl req -out CSR.csr -key privateKey.key -new

## generate CSR based on an existing certificate
  $ openssl x509 -x509toreq -in certificate.crt -out CSR.csr -signkey privateKey.key

## Remove passphrase from Private Key
  $ openssl rsa -in privateKey.pem -out newPrivateKey.pem

## Generate private key and self-signed certificate for localhost
  $ openssl req -x509 -out localhost.crt -keyout localhost.key \
  -newkey rsa:2048 -nodes -sha256 \
  -subj '/CN=localhost' -extensions EXT -config <( \
   printf "[dn]\nCN=localhost\n[req]\ndistinguished_name = dn\n[EXT]\nsubjectAltName=DNS:localhost\nkeyUsage=digitalSignature\nextendedKeyUsage=serverAuth")

[CONVERTING]
## Convert DER file (.crt .cer .der) to PEM
  $ openssl x509 -inform der -in certificate.cer -out certificate.pem

## Convert PEM file to DER
  $ openssl x509 -outform der -in certificate.pem -out certificate.der

## Convert PKCS#12 file (.pfx .p12) containing a private key and certificates to PEM
  $ openssl pkcs12 -in keyStore.pfx -out keyStore.pem -nodes
    You can add -nocerts to only output the private key or add -nokeys to only output the certificates.

## Convert PEM certificate file and a private key to PKCS#12 (.pfx .p12)
  $ openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile CACert.crt

--- MEDIA ---

## convert image with IMAGEMAGICK
  --> install imagemagick

  Change image format
    $ convert FILE_SRC.jpg FILE_DEST.png
  Reduce image quality
    $ convert FILE_SRC.jpg -quality X% FILE_DEST.jpg
  Resize image
    $ convert FILE_SRC.jpg -resize 200x300 FILE_DEST.jpg

shell_scripting

--- MISC ---

## sh-bang
  #!/bin/bash
  #!/usr/bin/env bash|python

## shell options
  set -o pipefail
  set -o errexit
  set -o nounset
  set -o xtrace

## include debug option in run
  DEBUG=${DEBUG:=0}
  [[ $DEBUG -eq 1 ]] && set -o xtrace

## redirect script output to stdout & in log file
  exec &> >(tee -a "/PATH/TO/FILE.LOG")

## prevent script to be executed (library case)
  if [ "${0}" == "${BASH_SOURCE[0]}" ]; then
    echo "This script is not meant to be executed directly!"
    echo "Use this script only by sourcing it."
    exit 1
  fi

## trap event
  trap 'cmd' EVENT1 EVENT2 EVENT3

  e.g: trap 'exit' INT TERM ERR

--- VARIABLES ---

## get current directory
  DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"

## array, list
  ARRAY=('VALUE_1' 'VALUE_2' 'VALUE_N')
  ARRAY=([NAME_1]='VALUE_1' [NAME_2]='VALUE_2' [NAME_N]='VALUE_N')
  declare -a ARRAY
    ARRAY[NAME_1]="VALUE_1"
    ARRAY[NAME_2]="VALUE_2"
    ARRAY[NAME_N]="VALUE_N"

  Get all values:
    ${ARRAY[@]}
  Get all names in index:
    ${!ARRAY[@]}

## parameter Substitution
--> http://www.tldp.org/LDP/abs/html/parameter-substitution.html#PARAMSUBREF
--> https://www.cyberciti.biz/tips/bash-shell-parameter-substitution-2.html

  - if not set, use default
      VAR=${VAR_EXPECTED:-default_value}
      VAR=${VAR_EXPECTED:-`cmd`}
      -> VAR=default_value

      Double assignment:
      VAR=${VAR_EXPECTED:=default_value}
      -> VAR=VAR_EXPECTED=default_value

  - if not set, print error message and exit 1
      VAR=${VAR_EXPECTED:?ERROR VAR_EXPECTED is not defined}

  - replace content
      a="b.c"
      d="${a/./-}"
      echo ${d} -> "b-c"

  - to uppercase
      VAR=${name^^}

  - to lowercase
      var=${VAR,,}

  - get last string of an URL
      ${VAR##*/}

--- ARRAY ---

## declare array var
  declare -A my_var
  my_var["content1"]="value1"
  my_var["content2"]="value2;

## append item to array
  declare -a ARRAY
  ARRAY=("a" "b")
  ARRAY+=("c" "d)

## array length
  ${#ARRAY_NAME[@]}

shell_system

## disable system beep
  $ rmmod pcspkr; echo "blacklist pcspkr" >>/etc/modprobe.d/blacklist.conf

ssl

## add trusted CA certificates
  install package "ca-certificates"
  $ cp CERT.cert /usr/local/share/ca-certificates/CERT.crt
  $ sudo /usr/local/share/ca-certificates/

## get certificate from URL
  $ openssl s_client -showcerts -connect URL:443 </dev/null 2>/dev/null|openssl x509 -outform PEM > CERT.pem

--- GET INFO ---

## check CSR (Certificate Signing Request)
	$ openssl req -text -noout -verify -in CSR.csr

## check Private Key
	$ openssl rsa -in privateKey.key -check

## check PEM formatted certificate
	$ openssl x509 -text -noout -in cert.{pem|crt}

## check DER formatted certificate
	$ openssl x509 -in MYCERT.der -inform der -text

## check PKCS#12 file (.pfx or .p12)
	$ openssl pkcs12 -info -in keyStore.p12

## check certificate from URL
	$ openssl s_client -showcerts -connect [URL]:443

## check expiration date
	$ echo | openssl s_client -connect example.com:443 -servername example.com 2>/dev/null | openssl x509 -noout -dates

## Check all SAN (Subject Alternative Name) in the certificate
	$ openssl s_client -connect website.com:443 | openssl x509 -noout -text | grep DNS:

--- GENERATE CERTIFICATE ---

## generate Private Key and Certificate Signing Request
	$ openssl req -out CSR.csr -new -newkey rsa:2048 -nodes -keyout privateKey.key

## generate self-signed certificate
	$ openssl req -x509 -sha256 -nodes -days 365 -newkey rsa:2048 -keyout privateKey.key -out certificate.crt

## generate CSR for existing private key
	$ openssl req -out CSR.csr -key privateKey.key -new

## generate CSR based on an existing certificate
	$ openssl x509 -x509toreq -in certificate.crt -out CSR.csr -signkey privateKey.key

## Remove passphrase from Private Key
	$ openssl rsa -in privateKey.pem -out newPrivateKey.pem

## Generate private key and self-signed certificate for localhost

	$ openssl req -x509 -out localhost.crt -keyout localhost.key \
  -newkey rsa:2048 -nodes -sha256 \
  -subj '/CN=localhost' -extensions EXT -config <( \
   printf "[dn]\nCN=localhost\n[req]\ndistinguished_name = dn\n[EXT]\nsubjectAltName=DNS:localhost\nkeyUsage=digitalSignature\nextendedKeyUsage=serverAuth")

--- CONVERTING USING OpenSSL ---

## Convert DER file (.crt .cer .der) to PEM
	$ openssl x509 -inform der -in certificate.cer -out certificate.pem

## Convert PEM file to DER
	$ openssl x509 -outform der -in certificate.pem -out certificate.der

## Convert PKCS#12 file (.pfx .p12) containing a private key and certificates to PEM
	$ openssl pkcs12 -in keyStore.pfx -out keyStore.pem -nodes

    You can add -nocerts to only output the private key or add -nokeys to only output the certificates.
   
## Convert PEM certificate file and a private key to PKCS#12 (.pfx .p12)
	$ openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile CACert.crt

trigram

A
amazon web service: aws            |cloud, aws
azure: az (local)

B

C
cluster: cls

D
development: dev                    |environment

E

F

G
google cloud platform: gcp          |cloud, gcp

H

I
ingress: ing                        |cloud, gcp
integration: int                    |environment
internal ip: iip                    |gcp, network

J

K
kubernetes: k8s (official), kub (local)     |cloud, container, kubernetes

L
laboratory: lab                     |environment
load balancer: lb                   |cloud, network

M

N

O
openShift: oc (local)               |cloud, kubernetes

P
production: prd                     |environment
pub/sub: psb                        |cloud, gcp
public ip: pip                      |gcp, network


Q
queue: qu                           |

R
route: rut                          |network

S

T

U

V
virtual machine: vm                 |cloud
virtual ip: vip                     |network

W

X

Y

Z

vim

## comment/un-comment mutiple lines
  +
  comment
  - visual block on needed lines: CTRL+V
  - insert mode on first line: SHIFT+I
  - add #
  - ECHAP
  un-comment
  - visual block on needed lines: CTRL+V
  - remove # on first line
  - ECHAP
  +
  comment:
  - shift-v
  - :norm i#
  uncomment:
  - shift-v
  - :norm x

 ## change colorscheme
  :colorscheme TAB

 ## if sudo forgotten
  :w !sudo tee %

## uppercase/lowercase
  ~    : case of current character
  guu  : current line from upper to lower.
  gUU  : current LINE from lower to upper.
  guw  : end of current WORD from upper to lower.
  guaw : all of current WORD to lower.
  gUw  : end of current WORD from lower to upper.
  gUaw : current WORD to upper.
  g~~  : Invert case to entire line
  g~w  : Invert case to current WORD
  guG  : lowercase until the end of document.
  gU)  : until end of sentence to upper case
  gu}  : end of paragraph to lower case
  gU5j : 5 lines below to upper case
  gu3k : 3 lines above to lower case

 --- VIMRC ---

 ## ident
  filetype plugin indent on
  " show existing tab with 4 spaces width
  set tabstop=4
  " when indenting with '>', use 4 spaces width
  set shiftwid  th=4
  " On pressing tab, insert 4 spaces
  set expandt ab

windows

## Create user profile file
  Test if file exists
  $ Test-Path $profile
  False

  Create user profile file
  $ New-Item -Path $PROFILE -ItemType File -Force
  C:\Users\$USER\Documents\WindowsPowerShell\Microsoft.PowerShell_profile.ps1

## Create Alias
  $ Get-Alias
  $ New-Alias ALIAS_NAME CMD_NAME
  or
  $ Set-Alias -Name ALIAS_NAME -Value 'CMD PARAM=VALUE'

## Create function
  Function _my_function {
    CMD PARAM=VALUE
  }

wps_linux

## add missing fonts

Download zip -> https://github.com/BannedPatriot/ttf-wps-fonts
  $ sudo mkdir -p /usr/share/fonts/truetype/msttcorefonts
  $ cd ttf-wps-fonts && sudo ./install.sh
  $ sudo fc-cache -fv