Start and Stop AWS EC2 instances based on tags

ec2-ops.sh

#!/bin/sh

set -e

function usage() {
  echo "$0 [-r <region> -t <TAG_KEY=value ...>] (start|stop|status)"
}

while getopts "t:r:" o; do
    case "${o}" in
        t)
            TAGS=${OPTARG}
            ;;
        r)
            REGION=${OPTARG}
            ;;
    esac
done
shift $((OPTIND-1))

if [ $# -ne 1 ]; then
  usage
  exit 2
fi

if [ -z "$REGION" ]; then
    REGION=$(aws configure get region)
fi

if [ ! -z "$TAGS" ]; then
    TAGS=$(echo "$TAGS" | tr ',' ' ')
    for PAIR in $TAGS; do
        TAG_QUERY="Tags[?Key=='$(echo "$PAIR" | cut -d'=' -f1)' && Value=='$(echo "$PAIR" | cut -d'=' -f2)']"
        if [ -z "$INSTANCES_QUERY" ]; then
            INSTANCES_QUERY="?$TAG_QUERY"
        else
            INSTANCES_QUERY="$INSTANCES_QUERY && $TAG_QUERY"
        fi
    done
    QUERY="Reservations[].Instances[$INSTANCES_QUERY].InstanceId"
fi

if [ -z "$QUERY" ]; then
    QUERY="Reservations[].Instances[].InstanceId"
fi

INSTANCES=$(aws ec2 describe-instances --region "$REGION" --query "$QUERY" --output text)

EXIT=0
if [ "$1" = "start" ]; then
  for instanceId in ${INSTANCES[@]}; do
      echo "Starting instance $instanceId..."
      aws ec2 start-instances --region "$REGION" --instance-ids "$instanceId"
  done
  EXIT=$?
elif [ "$1" = "stop" ]; then
  for instanceId in ${INSTANCES[@]}; do
      echo "Stopping instance $instanceId..."
      aws ec2 stop-instances --region "$REGION" --instance-ids "$instanceId"
  done
elif [ "$1" = "status" ]; then
  for instanceId in ${INSTANCES[@]}; do
    echo "$instanceId: $(aws ec2 describe-instance-status --region "$REGION" --instance-ids "$instanceId" --include-all-instances --query "InstanceStatuses[].[InstanceState][][Name]"  --output text)"
  done
  EXIT=$?
else
  usage
  EXIT=2
fi

exit "$EXIT"