Carl Tsai moonape1226

筆者最近在部署 Kubernetes 過程中，好奇每個元件究竟安裝與不安裝對 Kubernetes 造成什麼影響？CoreDNS 主要的功能之一是當 Pods 做套件更新或安裝時，可以提供 DNS Forward 功能，將請求轉發至外部進行 Domain 解析，並從正確的位址下載套件進行安裝。

本篇就聚焦在 CoreDNS 將 Pods 的請求轉發至外部 DNS Server 進行解析的運作流程。

問題描述

首先先檢視當前 Kubernetes 上運行的 Pods。

References

IEC 62351-4 Security Implementations for IEC 61850 MMS Messages
- https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=9115626
A Novel Approach for Mitigation of Replay and Masquerade Attacks in Smartgrids Using IEC 61850 Standard
- https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=8873588
IMPACT EVALUATION OF IEC 62351 CYBER SECURITY ON IEC 61850 COMMUNICATIONS PERFORMANCE
- https://www.cired-repository.org/bitstream/handle/20.500.12455/645/CIRED%202019%20-%201917.pdf?sequence=1
Evaluating Cryptographic Algorithms in IEC 61850 Networks
https://ieeexplore.ieee.org/abstract/document/9015196

Go supports modules since v1.11+.

Go modules require that GOPATH is empty => unset GOTPATH

Define a module

Run go mod init {module name} to create a go.mod file for the current directory.

For example go mod init github.com/brutella/dnssd creates the following content.

get name and image and startTime

kubectl get pods -Ao jsonpath='{range .items[*]}{@.metadata.name}{" "}{@..spec..containers[*].image}{" "}{@.status.phase}{" "}{@.status.startTime}{"\n"}{end}'

edited 10/2022 with .. and A suggestions

	version: "3"
	services:
	# configuration manager for NiFi
	zookeeper:
	hostname: myzookeeper
	container_name: zookeeper_container_persistent
	image: 'bitnami/zookeeper:3.7.0' # latest image as of 2021-11-09.
	restart: on-failure
	environment:
	- ALLOW_ANONYMOUS_LOGIN=yes

	# Testing process to expand k8s PVCs without losing data

	#region Install
	# Check the current cluster
	kubectl config current-context

	# Add bitnami repo
	helm repo list
	helm repo add bitnami https://charts.bitnami.com/bitnami

	'''


	This function send Application Load Balancer logs to CloudWatch Logs. So you can use CloudWatch tools, like Insight or custom metrics.
	By default, ALB log its access in gz file in S3, and there is no way yo send the log directly to a Log Group / Log Stream.
	This lambda function is triggered on S3 "PUT" action (when ALB write its log file). It then download the file localy, unzip it, sort it, and stream it to a CloudWatch log groups.

	Installation

	Activate ALB logs, and indicate the S3 bucket and the prefix for the log files. Enable, on the bucket, the deletion of old log files

	QUESTION 1
	Which SysV init configuration file should be modified to disable the ctrl-alt-delete key combination?
	A. /etc/keys
	B. /proc/keys
	C. /etc/inittab
	D. /proc/inittab
	E. /etc/reboot

	QUESTION 2
	Which of the following information is stored within the BIOS? (Choose TWO correct answers.)

	curl -I -X OPTIONS \
	-H "Origin: http://EXAMPLE.COM" \
	-H 'Access-Control-Request-Method: GET' \
	http://EXAMPLE.COM/SOMETHING 2>&1 \| grep 'Access-Control-Allow-Origin'

	#!/bin/bash
	LIFECYCLE_POLICY='{"rules":[{"rulePriority":10,"description":"keeps 50 latest tagged images","selection":{"tagStatus":"tagged","countType":"imageCountMoreThan","countNumber":50,"tagPrefixList":["v"]},"action":{"type":"expire"}},{"rulePriority":20,"description":"keeps 5 latest untagged images","selection":{"tagStatus":"untagged","countType":"imageCountMoreThan","countNumber":5},"action":{"type":"expire"}},{"rulePriority":30,"description":"keeps latest 20 numeric-tagged images","selection":{"tagStatus":"tagged","countType":"imageCountMoreThan","tagPrefixList":["0","1","2","3","4","5","6","7","8","9"],"countNumber":20},"action":{"type":"expire"}},{"rulePriority":40,"description":"keeps latest 20 a-f tagged images","selection":{"tagStatus":"tagged","countType":"imageCountMoreThan","tagPrefixList":["a","b","c","d","e","f"],"countNumber":20},"action":{"type":"expire"}}]}'
	aws ecr put-lifecycle-policy --region ${AWS_REGION} --repository-name ${REPO} --lifecycle-policy-text ${LIFECYCLE_POLICY} \|\| echo "Fa