akaron

# In terraform, the attribute of autoscaling group does not contain detail information of EC2 instances,
# i.e., cannot get the ip of instances for further usage (such as ansible). Of course it's better to make
# it no need to know the ip by using tools such as user-data of EC2 instance (for bootstrap) and LB and
# route 53.
#
# In case still want to know the ip addresses, one can use `data "aws_instances"` which 
# `depends_on = [aws_autoscaling_group.name]`, then use tags to get the information of instances.
# ref: https://github.com/terraform-providers/terraform-provider-aws/issues/511#issuecomment-447934405

provider "aws" {

akaron

# -*- mode: ruby -*-
# vi: set ft=ruby :

# ENV["LC_ALL"] = "en_US.UTF-8"

Vagrant.configure("2") do |config|
  config.vm.box = "ubuntu/xenial64"

  config.vm.provider "virtualbox" do |v|
    v.name = "tst_terraform_packer"

akaron

# run a kubernetes cluster in local VM using vagrant + k3s
# require: Virtualbox, vagrant
# steps: 
# * in the folder contain this `Vagrantfile`, run `vagrant up` and wait a bit for provisioning.
#   Once done, `vagrant ssh master` into the node and start using the k8s cluster,
#   such as `kubectl get nodes`, `kubectl get pods -A`, `kubectl get componentstatus`, 
#   or `kubectl run busybox --image=busybox:1.28 --rm --restart=Never -it -- nslookup kubernetes`
# * To clean up, logout these nodes, then run `vagrant destroy` to destroy the VMs.
#   - next time run `vagrant up` again to provision again
#   - or run `vagrant halt` to halt these VMs, and bring them back to the same state 

akaron

# nginx configuration for a reverse proxy for an existing jenkins, with SSL enabled
# modified from https://www.jenkins.io/doc/book/system-administration/reverse-proxy-configuration-nginx/
# Steps:
# 0. confirm jenkins is running; confirm a domain name is properly configured (apicat.xyz in this example)
#    - for instance, add the domain in aws route 53 or DO domain
#    - then add the NS record (aws or DO or others) back to where you register the domain (namecheap/godaddy/...)
#    - this may take some time (at least several minutes)
# 1. Put these config to nginx configuration (such as a new file in /etc/nginx/nginx-sites-enabled or append to /etc/nginx/nginx.conf)
# 2. update config if necessary: jenkins ip and port, root directories, server_name.
#   - run `sudo nginx -t` to verify the file

akaron

---
- hosts: master1
  become: yes 
  vars:
    - user_name: vagrant
  tasks:
    - name: install python virtualenv
      block:
        - name: install python virtualenv
          apt:

akaron

#!/bin/bash
# For ubuntu-18.04.5-live-server-amd64.iso
set -ex

# set-up repositories
apt-get update
apt-get upgrade -y
apt-get install -y apt-transport-https ca-certificates curl gnupg lsb-release ntp nfs-common
# add nfs-common if use nfs-provisioner

akaron

# put this to /etc/systemd/system
[Unit]
Description=watch log events and sendout mail when something happened

[Service]
ExecStart=/root/log_watcher.sh  # change the path, and make the file executable

[Install]
WantedBy=multi-user.target

akaron

#!/bin/bash
# get all deployments with name `redis-sentinel-manager` or `redis-cluster-manager`
# and patch these deploy with a nodeSelector with name similar to group-<ns>: <ns>

read -r -d '' tmpl <<'EOF'
kubectl -n i_ns patch deploy i_deploy --type='json' -p='[{"op": "add", "path": "/spec/template/spec/nodeSelector/group-i_ns", "value": "i_ns" }]'
EOF

# redis
ns_deploy=$(kubectl get deploy --all-namespaces|grep -E 'redis-.*-manager' | awk '{printf "%s+%s ", $1,$2}')

akaron

# use `kibana -> dev-tools -> console` or curl

# get cluster health
GET _cluster/health

# indices: the health should be green
GET _cat/indices?v

# shard: the state should be "STARTED"
GET _cat/shards?v

akaron

#!/usr/bin/env bash
# modified from: https://itnext.io/how-to-cold-start-fast-a-java-service-on-k8s-eks-3a7b4450845d
ns=$1
pod=$2
scheduled=`kubectl -n $ns get pod $pod -o json | jq -r '.status.conditions[] | select(.type=="PodScheduled") | .lastTransitionTime' | sed 's/T/ /g' | tr -d 'Z'`
ready=`kubectl -n $ns get pod $pod -o json | jq -r '.status.conditions[] | select(.type=="Ready") | .lastTransitionTime' | sed 's/T/ /g' | tr -d 'Z'`
scheduled_epoch=`date -u -d "$scheduled" +%s`
echo "${pod} sechedualed at ${scheduled_epoch}"
ready_epoch=`date -u -d "$ready" +%s`
load_seconds=$((ready_epoch-scheduled_epoch))