Dump env from Kubernetes secret & configmap which maps to global container ENVs.

env-local-dumper.sh

#!/bin/bash

set -e

ENV_SOURCE_FILE='.env'
OUTPUT_FILENAME='.env.production.local'
SECRET_DIRNAME='monoplace'
POSITIONAL=()

while [[ $# -gt 0 ]]; do
  key="$1"

  case $key in
  -s | --secret)
    SECRET_DIRNAME="$2"
    shift
    shift
    ;;
  -e | --env-source)
    ENV_SOURCE_FILE="$2"
    shift
    shift
    ;;
  -o | --output)
    OUTPUT_FILENAME="$2"
    shift
    shift
    ;;
  *)
    POSITIONAL+=("$1")
    shift
    ;;
  esac
done

set -- "${POSITIONAL[@]}"

SECRET_CATALOG="/etc/${SECRET_DIRNAME}"

if [ ! -d "${SECRET_CATALOG}" ]; then
    echo -e "Secret \"${SECRET_CATALOG}\" does not exist\n"
    exit
fi

if [ ! -f "$ENV_SOURCE_FILE" ]; then
    echo -e "File '$ENV_SOURCE_FILE' does not exists in this directory."
    exit;
fi

OUTPUT_FILE="./$OUTPUT_FILENAME"
rm "$OUTPUT_FILE"
touch "$OUTPUT_FILE"

# shellcheck disable=SC2002
cat "$ENV_SOURCE_FILE" | while IFS="=" read -r key value; do
    SECRET_FILE="$SECRET_CATALOG/$key"
    if [ -f "$SECRET_FILE" ]; then
        echo "$key=$(cat "$SECRET_FILE")" >> "$OUTPUT_FILE"
        echo "Find $key in the secret '$SECRET_FILE'"
        continue
    fi

    if [ -n "$(printenv "$key")" ]; then
        echo "$key=$(printenv "$key")" >> "$OUTPUT_FILE"
        echo "Find $key in the global env"
        continue
    fi

    echo "Doesn't find $key anywhere, use default"
    echo "$key=$value" >> "$OUTPUT_FILE"
done