gistfile1.txt

#!/bin/bash
function usage(){
  path="$BASH_SOURCE"
  cmd="$(basename $path)"
  if [[ ${path:0:1} != / ]]; then
    path="$(cd "$(dirname $path)"; pwd)/$cmd"
  fi
  if [[ ${1:-} == -q ]]; then
    if [[ -n ${2:-} ]]; then
      printf "${!2}"
    fi
    return
  fi
  example="email-confirmation-us-east-1:59"
  cat<<\
USAGE
Generate env var exports based on the environment defined in an AWS ECS task-definition
Usage:
  $cmd [-h]
  $cmd --init
  $cmd [-t] <task_definition_name>:<version>
Options:
  -h, --help    show this help
  -i, --init    output function wrapper (ideal for eval()ing in your shell rc/profile)
  -t, --task    name and version of task to get env vars from (default behavior even if flag omitted)
Examples:
  1. Make wrapper function available via shell rc/profile.
    in ~/.bash_profile or ~/.zprofile:
      source $path --init
    in bash/zsh:
      $cmd $example
  2. Execute script with task id to get export commands.
    in bash/zsh:
      $cmd $example
    output:
      export NODE_ENV="dev"
      export CONTENTFUL_ENV="master"
      ...
  3. Use eval to execute the export commands in the current shell.
    in bash/zsh:
      eval "\$($cmd $example)"
  4. Source script with task id to execute the export commands in the current shell.
    in bash/zsh:
      source $path $example
    or:
      . $path $example
USAGE
  return 1
}
function handle_usage_init_or_main(){
  if [[ -z ${1:-} || $1 =~ -?-help || $1 == -h ]]; then
    usage
  elif [[ $1 =~ -?-init || $1 == -i ]]; then
    init
  else
    if [[ $1 =~ -?-task || $1 == -t ]]; then
      shift
    fi
    if [[ $1 == -- ]]; then
      shift
    fi
    if [[ $0 == $BASH_SOURCE ]]; then
      main "$@"
    else
      eval "$(main "$@")"
    fi
  fi
}
function init(){
  printf 'function %s(){ source "%s" "$@"; }' "$(usage -q cmd)" "$(usage -q path)"
}
function main(){
    aws ecs describe-task-definition --task-definition "$@" | \
    jq -rf <(cat<<\
JQ_FILTER
          def env:
          .taskDefinition.containerDefinitions[].environment[]
          ;
          def key:
          map(select(.key == "name")) | .[].value
          ;
          def val:
          map(select(.key == "value")) | .[].value
          ;
          env | to_entries | "export \(key)=\(val | tojson)"
JQ_FILTER
    )
}
handle_usage_init_or_main "$@"
# vim: set et ts=2 sts=2 sw=2 :