Launch an app with environment variables pulled from aws secrets manager

withSecrets

#!/bin/sh

SELF=${0##*/}

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

log() {
    printf "$SELF: %s\n" "$@" >&2
}

dieIfNonZeroStatus() {
    estatus=$1 # some shells reserve $status
    if [ $estatus -ne 0 ]; then
        log "$*"
        exit $estatus
    fi
}

usage() {
    cat <<EOF
usage: $SELF [command [<args>]]

Launch an app with env vars pulled from aws secrets. The expanded
execution looks something like:

   env "some:port=5000" "some:env_name=stg" dotnet run myapp.exe

given invocation of:

   $SELF dotnet run myapp.exe

Examples:

   $SELF dotnet run --project SomeProject.csproj -- migrate-database

   $SELF --help
  
Debugging:

  A python session can help inspect the environment state:
  
     $SELF python
  
  In the repl, paste and run:
  
     import os; os.environ.keys(); os.environ["ek_cr:db:Port"]

EOF
}

requireCommand() {
    command -v $1 >/dev/null 2>&1 || die "'$1' is required, but not found"
}

requireCommand jq

[ $# -eq 0 ] && usage && exit 1;

while [ $# -gt 0 ]; do
    case "$1" in
        "")
            usage
            die "unrecognized argument: $1"
            exit 1
            ;;
        --help|help|-help|-h)
            usage
            exit 0
            ;;
        *)
            break
            ;;
    esac
done

secret_name="${AWS_SECRET_NAME:?missing aws secret name}"
aws_secret="$(aws secretsmanager get-secret-value --secret-id ${secret_name})"
dieIfNonZeroStatus $? "failed to fetch from aws secrets manager"

properties=$(printf "%s\n" "$aws_secret" \
  | jq '.SecretString
    | fromjson
    | to_entries[]
    | "\(.key)=\(.value)"
    ' \
  | perl -wp -e 's/^"(.*)"$/$1/' \
  | paste -sd\  - \
  )

env $properties "$@"