Docker entrypoint to add docker secrets to environment variables

docker-secrets-to-envs.sh

#!/usr/bin/env sh

set -e

file_env() {
  envName=$1
  secretName="${1}_FILE"
  eval var=\$"$envName"
  eval fileVar=\$"$secretName"
  def="${2:-}"

  # shellcheck disable=SC2154
  if [ "$var" != "" ] && [ "$fileVar" != "" ]; then
    echo "error: both $envName and $secretName are set (but are exclusive)"
    exit 1
  fi
  val="$def"
  if [ "$var" != "" ]; then
    val="${var}"
  elif [ "$fileVar" != "" ]; then
    val="$(cat "$fileVar")"
  fi
  export "$envName"="$val"
  unset "$secretName"
}

file_env "AWS_ACCESS_KEY_ID"
file_env "AWS_REGION"
file_env "AWS_SECRET_ACCESS_KEY"
# Add extra environment variables

exec "$@"