Watch CloudFormation Events during `aws cloudformation deploy`

aws-cloudformation-deploy-watcher.sh

#!/usr/bin/env bash
set -e

function echo_help {
  echo "usage: $0 [options]"
  echo ""
  echo "example: aws cloudformation deploy ... | $0 [options]"
  echo ""
  echo "options:"
  echo "  --stack-name"
  echo "  --profile"
  echo "  --region"
  echo "  --help"
}

function reverse {
    local output
    while read line
    do
      output="${line}\n${output}"
    done
    echo -en "${output}"
}

if [[ $# = 0 ]]
then
  >&2 echo_help
  exit 1
fi

opt_stack_name=''
opt_profile=''
opt_region=''
while [[ $# -gt 0 ]]; do
  case $1 in
    --stack-name) opt_stack_name="$2"; shift 2;;
    --profile)    opt_profile="$2"; shift 2;;
    --region)     opt_region="$2"; shift 2;;
    --help)       echo_help; exit 0;;
    *)
      >&2 echo "[ERROR] unexpected argument: $1"
      >&2 echo_help
      exit 1;;
  esac
done

if [[ ! "${opt_stack_name}" ]]
then
  >&2 echo "[ERROR] '--stack-name' parameter missing"
  >&2 echo_help
  exit 1
fi

exit_code=0
while read line
do
    echo "${line}"
    if [[ "${line}" = "Waiting for stack create/update to complete" ]]
    then
        while true
        do
            recent_deploy_events="$(aws cloudformation describe-stack-events --stack-name "${opt_stack_name}" \
                $([[ "$opt_profile" ]] && echo "--profile" "$opt_profile") \
                $([[ "$opt_region" ]] && echo "--region" "$opt_region") \
                --query 'StackEvents[*].[Timestamp,ResourceType,LogicalResourceId,ResourceStatus,ResourceStatusReason]' --output text \
                | awk "NR==1,/\tAWS::CloudFormation::Stack\t${opt_stack_name}\t.*\tUser Initiated\$/" | reverse)"

            comm -13 <(echo "${prior_deploy_events:-}") <(echo "${recent_deploy_events}") \
                | awk -F '\t' '{printf "%s   %-32s   %-32s   %-24s   %s\n",$1,$2,$3,$4,$5}' \
                | sed 's/None$//'

            tab=$'\t'

            if (echo "${recent_deploy_events}" | grep -q "AWS::CloudFormation::Stack${tab}${opt_stack_name}${tab}.*\(_ROLLBACK_COMPLETE|_FAILED\)${tab}")
            then
                exit_code=1
                break
            fi

            if (echo "${recent_deploy_events}" | grep -q "AWS::CloudFormation::Stack${tab}${opt_stack_name}${tab}.*\(_COMPLETE\)${tab}")
            then
                exit_code=0
                break
            fi

            prior_deploy_events="${recent_deploy_events}"

            sleep 2
        done
    fi
done

exit ${exit_code}