AWS CLI をつかってELBから抜いたインスタンスにコマンド実行して再追加する

#! /bin/bash

TAGN=Role
TAGV=ap
ELB=elb-waiters-test
SLEEP=5

# 引数すべてを一つのコマンドとして格納
CMD=$@

# AWS CLI で取得したインスタンス（タグでフィルタリング）からInstanceIdとPublicIPを取得
instances=($(aws ec2 describe-instances  --filter "Name=tag:${TAGN},Values=${TAGV}" |  jq '.Reservations[].Instances[]| (.InstanceId + "," + .PublicDnsName)' | sed -e 's/"//g'))

# 自作Waiter
waiter(){
  while :;do
    state=$(aws elb describe-instance-health --load-balancer-name $1  --instances $2 | jq '.InstanceStates[].State')
    if [ "$3" = "$state" ] ;then
        break
    else
        echo "  InstanceId:$2 State:$state"
    fi
    sleep $SLEEP
  done
}

# ELBを取り外してSSHでコマンド発行してELB取り付ける
for instance in "${instances[@]}"; do
  DNS="${instance#*,}"
  ID="${instance%,*}"

  # ELB からインスタンスの取り外し
  echo "Deregister ELB:$ELB InstanceId:$ID"
  aws elb deregister-instances-from-load-balancer --load-balancer-name $ELB --instances $ID > /dev/null

  # OutOfServiceになるまで待機
  waiter $ELB $ID '"OutOfService"'

  # コマンド発行(Ubuntu環境利用してるもので…)
  ssh ubuntu@$DNS "bash -c '$CMD'"

  # ELB へインスタンスの取り付け
  echo "Register ELB:$ELB InstanceId:$ID"
  aws elb register-instances-with-load-balancer   --load-balancer-name $ELB --instances $ID > /dev/null

  # InServiceになるまで待機
  waiter $ELB $ID '"InService"'
done

$ ./command.sh uptime
Deregister ELB:elb-waiters-test InstanceId:i-3e7bfccd
  InstanceId:i-3e7bfccd State:"InService"
  InstanceId:i-3e7bfccd State:"InService"
  InstanceId:i-3e7bfccd State:"InService"
 11:11:50 up 53 min,  0 users,  load average: 0.00, 0.01, 0.04
Register ELB:elb-waiters-test InstanceId:i-3e7bfccd
  InstanceId:i-3e7bfccd State:"OutOfService"
  InstanceId:i-3e7bfccd State:"OutOfService"
  InstanceId:i-3e7bfccd State:"OutOfService"
Deregister ELB:elb-waiters-test InstanceId:i-7de78c64
  InstanceId:i-7de78c64 State:"InService"
  InstanceId:i-7de78c64 State:"InService"
  InstanceId:i-7de78c64 State:"InService"
 11:12:30 up  1:12,  0 users,  load average: 0.00, 0.01, 0.05
Register ELB:elb-waiters-test InstanceId:i-7de78c64
  InstanceId:i-7de78c64 State:"OutOfService"
  InstanceId:i-7de78c64 State:"OutOfService"
$
$ ./command.sh sudo service nginx restart
Deregistee ELB:elb-waiters-test InstanceId:i-3e7bfccd
  InstanceId:i-3e7bfccd State:"InService"
  InstanceId:i-3e7bfccd State:"InService"
  InstanceId:i-3e7bfccd State:"InService"
 * Restarting nginx nginx
   ...done.
Register ELB:elb-waiters-test InstanceId:i-3e7bfccd
  InstanceId:i-3e7bfccd State:"OutOfService"
  InstanceId:i-3e7bfccd State:"OutOfService"
  InstanceId:i-3e7bfccd State:"OutOfService"
Deregister ELB:elb-waiters-test InstanceId:i-7de78c64
  InstanceId:i-7de78c64 State:"InService"
  InstanceId:i-7de78c64 State:"InService"
 * Restarting nginx nginx
   ...done.
Register ELB:elb-waiters-test InstanceId:i-7de78c64
  InstanceId:i-7de78c64 State:"OutOfService"
  InstanceId:i-7de78c64 State:"OutOfService"
  InstanceId:i-7de78c64 State:"OutOfService"