deploy

#!/bin/bash
set -o errexit
set -o pipefail
set -u

function usage {
    set -e
    cat <<EOM
    deploy -c cluster-name -n service-name --asg ASG name
EOM

    exit 2
}
if [ $# == 0 ]; then usage; fi

# Check requirements
function require {
    command -v "$1" > /dev/null 2>&1 || {
        echo "Some of the required software is not installed:"
        echo "    please install $1" >&2;
        exit 1;
    }
}

function getRunningTaskInstance {
  local cluster=$1

  local instances=$( aws ecs list-container-instances --cluster $cluster )
  local list=$(echo $instances | jq -r '.containerInstanceArns|join(" ")')
  local containerInstances=$( aws ecs describe-container-instances \
    --cluster $CLUSTER \
    --container-instances ${list} | jq '.containerInstances' )
  local runningTaskInstances=$( echo $containerInstances | jq -r '[ .[]|select(.runningTasksCount > 0)|.ec2InstanceId ] | join(" ")' )
  echo $runningTaskInstances
}

function scaleIn {
  local cluster=$1
  local asgName=$2
  local asgDesiredCapacity=$3
  local newAsgDesiredCapacity=$4

  runningTaskInstances=$( getRunningTaskInstance $cluster )

  aws autoscaling set-instance-protection \
    --auto-scaling-group-name $asgName \
    --instance-ids ${runningTaskInstances} \
    --protected-from-scale-in

  echo "[INFO] cluster scale in: $newAsgDesiredCapacity -> $asgDesiredCapacity"
  aws autoscaling set-desired-capacity \
    --auto-scaling-group-name $asgName \
    --desired-capacity $asgDesiredCapacity > /dev/null

  local i=0
  local every=10
  while [ $i -lt $TIMEOUT ]
  do
    size=$( aws ecs list-container-instances --cluster $cluster | jq '.containerInstanceArns|length' )
    if [ $size = $asgDesiredCapacity ]; then
      aws autoscaling set-instance-protection \
        --auto-scaling-group-name $asgName \
        --instance-ids ${runningTaskInstances} \
        --no-protected-from-scale-in
      echo "[INFO] scale in successfully."
      exit 0
    fi
    sleep $every
    i=$(( $i + $every ))
  done
  echo "[ERROR] cluster scale-in not finishing within $TIMEOUT seconds"
}

# Check for AWS, AWS Command Line Interface
require aws
# Check for jq, Command-line JSON processor
require jq

# args
CLUSTER=false
SERVICE=false
ASG_NAME=false
TIMEOUT=900

# Loop through arguments, two at a time for key and value
while [[ $# -gt 0 ]]
do
    key="$1"

    case $key in
        --asg)
            ASG_NAME="$2"
            shift
            ;;
        -c|--cluster)
            CLUSTER="$2"
            shift
            ;;
        -n|--service-name)
            SERVICE="$2"
            shift # past argument
            ;;
        -t|--timeout)
            TIMEOUT="$2"
            shift
            ;;
        *)
            usage
            exit 2
        ;;
    esac
    shift # past argument or value
done

asg=$( aws autoscaling describe-auto-scaling-groups --auto-scaling-group-name $ASG_NAME )
asgInstances=$( echo $asg \
  | jq '.AutoScalingGroups[] | [.Instances[]|select(.LifecycleState == "InService")]' )
asgDesiredCapacity=$( echo $asg  | jq '.AutoScalingGroups[0].DesiredCapacity' )
newAsgDesiredCapacity=$(( $asgDesiredCapacity * 2 ))

echo "[INFO] cluster scale out: $asgDesiredCapacity -> $newAsgDesiredCapacity"
aws autoscaling set-desired-capacity \
  --auto-scaling-group-name $ASG_NAME \
  --desired-capacity $newAsgDesiredCapacity > /dev/null

ecsDeployExitCode=0
./ecs-deploy -c $CLUSTER -n $SERVICE || ecsDeployExitCode=$?

if [ $ecsDeployExitCode != 0 ]; then
  echo "[INFO] rollback cluster size: $newAsgDesiredCapacity -> $asgDesiredCapacity"
  scaleIn $CLUSTER $ASG_NAME $asgDesiredCapacity $newAsgDesiredCapacity
  exit 1
fi

scaleIn $CLUSTER $ASG_NAME $asgDesiredCapacity $newAsgDesiredCapacity