Initial code

.editorconfig

+# Drupal editor configuration normalization
+# @see http://editorconfig.org/
+
+# This is the top-most .editorconfig file; do not search in parent directories.
+root = true
+
+# All files.
+[*]
+end_of_line = LF
+indent_style = space
+indent_size = 2
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[{composer.json,composer.lock}]
+indent_size = 4

.gitignore

+vendor
+composer.lock

.gitlab-ci.yml

+Deploy:
+  stage: deploy
+  script:
+    - curl -XPOST -H'content-type:application/json' "https://packagist.org/api/update-package?username=${PACKAGIST_USERNAME}&apiToken=${PACKAGIST_API_TOKEN}" -d'{"repository":{"url":"'${CI_PROJECT_URL}'"}}'

Dotenv.php

+<?php
+
+namespace LakeDrops\Component\Dotenv;
+
+use Symfony\Component\Dotenv\Dotenv as SymfonyDotenv;
+
+/**
+ * Manages .env files.
+ */
+final class Dotenv {
+
+  /** @var string */
+  private $name;
+
+  /** @var \Composer\IO\IOInterface */
+  private $io;
+
+  /** @var \Symfony\Component\Dotenv\Dotenv */
+  private $dotenv;
+
+  /**
+   * Dotenv constructor.
+   *
+   * @param string $name
+   * @param \Composer\IO\IOInterface $io
+   */
+  public function __construct($name, $io) {
+    $this->name = strtoupper($name);
+    $this->io = $io;
+    $this->dotenv = new SymfonyDotenv();
+    $this->load();
+  }
+
+  /**
+   * @param string $key
+   * @param string $prompt
+   *
+   * @return string
+   */
+  public function receive($key, $prompt) {
+    $key = $this->name . '_' . strtoupper($key);
+    $value = getenv($key);
+    if (empty($value)) {
+      if ($this->io->isInteractive()) {
+        $value = $this->io->ask($prompt . ': ');
+        $this->putenv($key, $value);
+      }
+    }
+    return $value;
+  }
+
+  private function load() {
+    try {
+      $this->dotenv->load('.env');
+    }
+    catch (\Exception $ex) {
+      // Ignore
+    }
+  }
+
+  private function putenv($key, $value) {
+    $env = file_exists('.env') ? file_get_contents('.env') : '';
+    $env .= PHP_EOL . $key . '=' . $value . PHP_EOL;
+    file_put_contents('.env', $env);
+    $this->load();
+  }
+
+}

README.md

+# Dotenv
+

composer.json

+{
+    "name": "lakedrops/dotenv",
+    "description": "Composer Library as wrapper around symfony/dotenv",
+    "type": "library",
+    "keywords": ["Drupal", "Development", "Dotenv"],
+    "homepage": "https://gitlab.lakedrops.com/lakedrops/dotenv",
+    "license": "GPL-2.0+",
+    "authors": [
+        {
+            "name": "Jürgen Haas",
+            "email": "juergen@paragon-es.de",
+            "homepage": "https://www.paragon-es.de",
+            "role": "Drupal Expert"
+        },
+        {
+            "name": "Richard Papp",
+            "email": "richard.papp@boromino.com",
+            "homepage": "http://www.boromino.com",
+            "role": "Drupal Expert"
+        }
+    ],
+    "support": {
+        "issues": "https://gitlab.lakedrops.com/lakedrops/dotenv/issues",
+        "source": "https://gitlab.lakedrops.com/lakedrops/dotenv/tree/master"
+    },
+    "require": {
+        "php": ">=5.4.5",
+        "symfony/dotenv": "^3.3"
+    },
+    "autoload": {
+        "psr-4": { "LakeDrops\\Component\\Dotenv\\": "" }
+    },
+    "require-dev": {
+        "composer/composer": "dev-master",
+        "phpunit/phpunit": "^4.4.0"
+    }
+}