ecs_runtask_andwaitfor.sh

#!/bin/sh
#
# Script for unique running an aws_ecs_task and wait until it is finished.
# 
# ONLY TESTED FOR FARGATE_CLUSTERS
#
# REQUIREMENTS
# * aws cli
# * AWS-credential ENV's
#
# Example Usage:
# ./runtask_test.sh -r "eu-central-1" -c "vms-prod-app-frontend" -s "migration" -l "FARGATE" -t "vms-prod-frontend-api-router" -o '{"containerOverrides": [{"name": "vms-prod-frontend-api-router", "command": ["kong", "migrations", "up"]}]}' -n '{"awsvpcConfiguration": {"subnets": ["subnet-0dab18f06351fce1f"], "securityGroups": ["sg-0bd674652dbe13f31"], "assignPublicIp": "DISABLED"}}'
#


REGION=""
CLUSTER=""
STARTED_BY=""
LAUNCH_TYPE=""
TASK_DEFINITION=""
OVERRIDES=""
NETWORK_CONFIGURATION=""

###
# get arguments
while getopts ':r:c:s:l:t:o:n:' opt; do
    echo "${opt}: ${OPTARG}"
    case ${opt} in
        r)
            REGION=${OPTARG}
            ;;
        c)
            CLUSTER=${OPTARG}
            ;;
        s)
            STARTED_BY=${OPTARG}
            ;;
        l)
            LAUNCH_TYPE=${OPTARG}
            ;;
        t)
            TASK_DEFINITION=${OPTARG}
            ;;
        o)
            OVERRIDES=${OPTARG}
            ;;
        n)
            NETWORK_CONFIGURATION=${OPTARG}
            ;;
    esac
done

####
# check arguments
if [ -z "$REGION" ]; then
    echo "-r <region> is required"
    exit 1
fi

if [ -z "$CLUSTER" ]; then
    echo "-c <clustername> is required"
    exit 1
fi

if [ -z "$STARTED_BY" ]; then
    STARTED_BY=$(cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 32 | head -n 1)
fi

if [ -z "$LAUNCH_TYPE" ]; then
    LAUNCH_TYPE="EC2"
fi

if [ -z "$TASK_DEFINITION" ]; then
    echo "-t <task definition> is required"
    exit 1
fi

if [ -z "$OVERRIDES" ]; then
    OVERRIDES="{}"
fi

if [ -z "$NETWORK_CONFIGURATION" ]; then
    NETWORK_CONFIGURATION="{}"
fi


###
# GLOBALS
WAIT_TIMEOUT="1s"
START=$(date +%s)


checkRunningTasksStartedBy()
{
    RUNNING_TASK_COUNT=`aws ecs list-tasks \
        --region ${REGION} \
        --cluster ${CLUSTER} \
        --started-by ${STARTED_BY} \
        --output text | wc -l`
}

getStatusForTaskArn()
{
    TASK_ARN=$1

    STATUS=`aws ecs describe-tasks \
        --region ${REGION} \
        --cluster ${CLUSTER} \
        --task ${TASK_ARN} \
        --output text \
        --query "tasks[0].containers[0].lastStatus"`
}

getExitCodeForTaskArn()
{
    TASK_ARN=$1

    EXIT_CODE=`aws ecs describe-tasks \
        --region ${REGION} \
        --cluster ${CLUSTER} \
        --task ${TASK_ARN} \
        --query "tasks[0].containers[0].exitCode"`
}


runTaskStartedBy()
{
    TASK_ARN=`aws ecs run-task \
        --region ${REGION} \
        --cluster ${CLUSTER} \
        --started-by ${STARTED_BY} \
        --launch-type ${LAUNCH_TYPE} \
        --task-definition ${TASK_DEFINITION} \
        --overrides "${OVERRIDES}" \
        --network-configuration "${NETWORK_CONFIGURATION}" \
        --output text \
        --query 'tasks[0].taskArn'`
}



RUNNING_TASK_COUNT=1
while [ ${RUNNING_TASK_COUNT} -ne 0 ]; do
    checkRunningTasksStartedBy
    NOW=$(date +%s)
    if [ ${RUNNING_TASK_COUNT} -ne 0 ];
    then
        echo "${RUNNING_TASK_COUNT} Migration-Tasks already running. Wait 5 seconds for exit. $(( $NOW - $START ))s elapsed."
        sleep ${WAIT_TIMEOUT}
    else
        echo "No Migration-Tasks is running, starting it now. $(( $NOW - $START ))s elapsed."
        break
    fi
done


runTaskStartedBy
if [ $? -ne 0 ]; then
    NOW=$(date +%s)
    echo "Could not start task. Exit with error. $(( $NOW - $START ))s elapsed."
    exit 1
fi
echo "Task started: ${TASK_ARN}"

STATUS="RUNNING"
while [ "${STATUS}" != "STOPPED" ]; do

    getStatusForTaskArn "${TASK_ARN}"
    NOW=$(date +%s)
    if [ "${STATUS}" != "STOPPED" ];
    then
        echo "The Migration-Tasks is running. Wait 5 seconds for exit. $(( $NOW - $START ))s elapsed."
        sleep ${WAIT_TIMEOUT}
    else
        NOW=$(date +%s)
        echo "The Migration-Tasks has finished. Checking exit-code now. $(( $NOW - $START ))s elapsed."

        getExitCodeForTaskArn "${TASK_ARN}"
        NOW=$(date +%s)
        if [ "${EXIT_CODE}" -ne "0" ];
        then
            echo "Exit code is ${EXIT_CODE}. Exiting with error. $(( $NOW - $START ))s elapsed."
            exit 1
        else
            echo "Exit code is 0. Well done. $(( $NOW - $START ))s elapsed."
            exit 0
        fi
    fi
done