Bash script to make ECS Exec (aws ecs execute-command) useful

#!/bin/bash

# Bash script to run ecs-exec on Amazon ECS Fargate containers.
#
# Usage: See --help.
#
# Installation: Download the script and `chmod u+x the script`.
#  curl https://gist.githubusercontent.com/yuki777/640cba3e0a68587c36165b8a87d25390/raw/5bfa8242ba00ed336da76711d602e6df4f76a452/sssh -o sssh && chmod u+x sssh
#  ./sssh
#
# Prerequisites (validated)
# - aws cli
# - session-manager-plugin
# - jq
#
# Special thanks to contributor
# - leewc

set -eu

selectProfile(){
    # profile parameter not supplied.
    if [ -z ${profile+x} ]; then
        # only works with AWS CLIv2.
        select selected in `aws configure list-profiles`
        do
            break
        done
        echo $selected
    else
        echo $profile
    fi
}

params(){
    echo "$(profileParam) $(regionParam)"
}

profileParam() {
    [[ $profile ]] &>/dev/null && echo "--profile $profile"
}

regionParam() {
    [[ $region ]] &>/dev/null && echo "--region $region"
}

selectCluster(){
    select selected in $(aws ecs list-clusters $(params)|jq -r ".clusterArns[]"|sort|cut -d "/" -f 2)
    do
        break
    done
    echo $selected
}

selectService(){
    select selected in $(aws ecs list-services $(params) --cluster $cluster|jq -r ".serviceArns[]"|sort)
    do
        break
    done
    echo $selected
}

selectTask(){
    select selected in $(aws ecs list-tasks $(params) --cluster $cluster --service-name $service --desired-status RUNNING |jq -r '.taskArns[]'|sort)
    do
        break
    done
    echo $selected
}

selectContainer(){
    select selected in $(aws ecs describe-tasks $(params) --cluster $cluster --tasks $task | jq -r ".tasks[].containers[].name"|sort)
    do
        break
    done
    echo $selected
}

colorEcho(){
    red='\033[0;31m'
    green='\033[0;32m'
    yellow='\033[0;33m'
    reset='\033[0m'

    if echo $@ | egrep -q "prd|prod|production"; then
        color=$red
    elif echo $@ | egrep -q "stg|stage|staging|beta|devo"; then
        color=$yellow
    else
        color=$green
    fi

    echo -e "${color}$@${reset}"
}

echo_stderr() {
    echo -e "$@" >&2
}

die() {
    echo_stderr "$@"
    exit 1
}

validatePrereq() {
    command -v jq  &>/dev/null || die "jq not installed on host. Please install jq. See https://stedolan.github.io/jq/download/"
    command -v session-manager-plugin &>/dev/null || die "session-manager-plugin not installed. See https://docs.aws.amazon.com/systems-manager/latest/userguide/session-manager-working-with-install-plugin.html"
    command -v aws &>/dev/null || die "AWS CLI not found, AWS CLI version 1.16.12 or later must be installed. See https://docs.aws.amazon.com/cli/latest/userguide/getting-started-install.html"
    # Checks if AWS CLI is outdated or not., v1 of AWS CLI pipes to std error, redirect
    AWS_CLI_VERSION=$(aws --version 2>&1 | awk '{ print $1 }' | cut -d/ -f2)
    echo_stderr "You have AWS CLI v$AWS_CLI_VERSION installed."
    # Do a best effort check for v1 (so that it's at least 1.10 and up.
    [[ $AWS_CLI_VERSION =~ ^1.1[0-9] || $AWS_CLI_VERSION =~ ^2 ]] &>/dev/null || die "AWS CLI version 1.16.12 or later must be installed to support ecs-exec, Run 'aws --version' to see what you have. See https://docs.aws.amazon.com/cli/latest/userguide/getting-started-install.html"
}

function print_help() {
    cat >&2 <<-END

This script simplifies the process of getting the required information to drop into an
interactive shell script on your container hosted on Fargate/ECS.

Example:

./sssh --region us-west-2
./sssh --profile default

Supported input parameters:
 -r | --region  : AWS Region to fetch the cluster, service, task
 -p | --profile : AWS Profile for credentials and region.
 -c | --command : Command to execute, defaults to '/bin/sh'/

The default command executed on the selected container is '/bin/sh'.
If a region is not provided, the script will attempt to use your region set in the profile.
If you want to execute a different command or shell, you can pass it in like so:

./sssh --command '/bin/bash'

You need active (unexpired) AWS credentials, otherwise, the script will crash.

Updates on https://gist.githubusercontent.com/leewc/e4c3a16551b06c2b0b4640fa5a3d9c00

END
}

main(){
    command='/bin/sh'
    while [[ "$#" -gt 0 ]]; do
        case $1 in
            -h|--help)
                print_help
                exit
                ;;
            -r|--region)
                shift
                region="${1:?Region must be specified in --region}"
                shift
                ;;
            -p|--profile)
                shift
                profile="${1:?Profile must be specified in --profile}"
                shift
                ;;
            -c|--command)
                shift
                command="${1:?Command must be specified in --command}"
                shift
                ;;
            *)
                die "Unknown param $1"
                ;;
        esac
    done

    echo_stderr "Validating pre-requisites...."
    validatePrereq

    # spaces matter :)
    if [[ $AWS_CLI_VERSION =~ ^2 ]] ; then
        echo_stderr "Select AWS Profile."
        profile=`selectProfile`
        colorEcho profile: $profile
    else echo_stderr "[INFO] AWS CLI is not v2, unable to select profile. --region or --profile must be set."
    fi
    echo_stderr

    echo_stderr "Select cluster."
    cluster=`selectCluster`
    colorEcho cluster: $cluster
    echo_stderr

    echo_stderr "Select service."
    service=`selectService`
    colorEcho service: $service
    echo_stderr

    echo_stderr "Select task."
    task=`selectTask`
    colorEcho task: $task
    echo_stderr

    echo_stderr "Select container."
    container=`selectContainer`
    colorEcho container: $container
    echo_stderr

    echo_stderr "Executing command (you might have to upgrade your AWS CLI if this fails)"
    cmd="aws ecs execute-command $(params) --cluster $cluster --container $container --task $task --interactive --command '$command'"
    colorEcho $cmd

    $cmd
}

# Execute main function and pass all params over
main $@

# Download it, save it any name you like, `chmod` it.
curl https://gist.githubusercontent.com/yuki777/640cba3e0a68587c36165b8a87d25390/raw/5bfa8242ba00ed336da76711d602e6df4f76a452/sssh -o sssh
chmod 744 sssh
./sssh

# Select aws profile from `aws configure list-profiles`
Select aws profile.
1) default
2) foo-bar
#? 2
profile: foo-bar

# Select cluster from `aws ecs list-clusters`
Select cluster.
1) dev-foo-bar-cluster          9) prod-foo-app-cluster
2) prd-foo-hoge-ad-cluster      10) stg-foo-app-cluster
3) prd-foo-hoge-cluster         11) stg-foo-hoge-cluster
4) prd-foo-piyo2021-ad-cluster  12) stg-foo-piyo2021-cluster
5) prd-foo-piyo2021-cluster     13) stg-foo-bar-cluster
6) prd-foo-bar-ad-cluster       14) stg-foo-tags-cluster
7) prd-foo-bar-cluster          15) hoge-foo-bar-cluster
8) prd-foo-tags-cluster
#? 1
cluster: dev-foo-bar-cluster

# Select service from `aws ecs list-services`
 1) arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-qa-1125-service
 2) arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-qa-1206-service
 3) arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-qa-1249-service
 4) arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-qa-1275-service
 5) arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-qa-1323-service
 6) arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-qa-1348-service
 7) arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-qa-1349-service
 8) arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-qa-1384-service
 9) arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-qa-1386-service
10) arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-qa-1391-service
11) arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-qa-1397-service
12) arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-qa-1399-service
13) arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-qa-1412-service
14) arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-qa-1413-service
15) arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-qa-1419-service
16) arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-qa-1420-service
17) arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-service
#? 16
service: arn:aws:ecs:ap-northeast-1:************:service/dev-foo-bar-cluster/dev-foo-bar-qa-1420-service

# Select task from `aws ecs list-tasks`
1) arn:aws:ecs:ap-northeast-1:************:task/dev-foo-bar-cluster/********************************
#? 1
task: arn:aws:ecs:ap-northeast-1:************:task/dev-foo-bar-cluster/********************************

# Select container from `aws ecs describe-tasks`
1) container-foo
2) container-bar
3) container-hoge
4) container-piyo
#? 1
container: container-foo

# Show command
aws ecs execute-command --profile foo-bar --cluster dev-foo-bar-cluster --container container-foo --task arn:aws:ecs:ap-northeast-1:************:task/dev-foo-bar-cluster/******************************** --interactive --command '/bin/sh'

The Session Manager plugin was installed successfully. Use the AWS CLI to start a session.

# Start your session and run command from `aws ecs execute-command`
Starting session with SessionId: ecs-execute-command-*****************
/path/to/home # :)