Download All Lambda Functions

download_all_lambda_functions.sh

#!/bin/bash
#
# Usage:
#  ./download_all.sh
#  ./download_all.sh download us-east-1 my-function
#  ./download_all.sh help
#
# Downloads all aws-lambda functions to a subdirectory
# Assumes you have a role that has at least read access to lambda.
# Credits to https://gist.github.com/nemani/defdde356b6678352bcd4af69b7fe529

set -euo pipefail
IFS=$'\n\t'
# Influenced by https://dev.to/thiht/shell-scripts-matter
# And see https://github.com/bf4/Notes/wiki/Shell-Scripting

abort=0
show_help() {
 abort=${abort:0}
 sed -ne '/^#/!q;s/.\{1,2\}//;1d;p' < "$0" >&$((abort+1))
 exit $abort
}

# shellcheck disable=SC2034
export AWS_PROFILE="${AWS_PROFILE:-your-profile-here}"
readonly DOWNLOAD_PATH_BASE="./lambda_functions"

# trap ctrl-c and call ctrl_c()
trap ctrl_c INT
ctrl_c() {
  echo "** CTRL-C Detected - aborting..."
  exit 1
}

get_function_names() {
  local region; region="$1"
  aws lambda list-functions --region "$region" --query 'Functions[].FunctionName' --output text
}

get_function() {
  local region; region="$1"
  local function_name; function_name="$2"
  local download_path
  download_path="${DOWNLOAD_PATH_BASE}/$region/$function_name"
  mkdir -p "$download_path"
  aws lambda get-function --function-name "$function_name" --region "$region" --query 'Code.Location' \
    | xargs wget --quiet -O "$download_path/$function_name.zip"

  unzip -o -f -d "$download_path" "$download_path/$function_name.zip"
}

download_region(){
  local region; region="$1"
  echo "searching region: $region"
  for function_name in $(get_function_names "$region"); do
    get_function "$region" "$function_name"
  done
}

get_regions(){
  aws ec2 describe-regions --query "Regions[].{Name:RegionName}" --output text | sort -r
}

main() {
  # search all regions
  for region in $(get_regions); do
    download_region "$region"
  done

  echo "Completed Downloading all the Lamdba Functions!"
}

case "${1:-}" in
  help|-h|--help)
    show_help
  ;;

  download)
    shift
    get_function "$1" "$2"
  ;;

  *)
    shift
    main
  ;;
esac