Updated configuration to support Docker Swarm secrets

docs/Options.md

@@ -1,6 +1,7 @@
 # Options
 
-The following environment variables are used by Ackee. You can also create a [`.env` file](https://www.npmjs.com/package/dotenv) in the root of the project to store all variables in one file.
+The following environment variables are used by Ackee. You can also create a [`.env` file](https://www.npmjs.com/package/dotenv) in the root of the project to store all variables in one file. All environment
+variables also support a `_FILE` suffix, which will fetch the value from the specified file path.
 
 - [Database](#database)
 - [Port](#port)

src/utils/config.js

@@ -1,24 +1,44 @@
 'use static'
 
+const fs = require('fs')
 const { day } = require('./times')
 
 // Must be a function or object that loads and returns the env variables at runtime.
 // Otherwise it wouldn't be possible to mock the env variables with mockedEnv.
 module.exports = new Proxy({}, {
 	get: function(target, prop) {
 		const data = {
-			ttl: process.env.ACKEE_TTL || day,
-			port: process.env.ACKEE_PORT || process.env.PORT || 3000,
-			dbUrl: process.env.ACKEE_MONGODB || process.env.MONGODB_URI,
-			allowOrigin: process.env.ACKEE_ALLOW_ORIGIN,
-			autoOrigin: process.env.ACKEE_AUTO_ORIGIN === 'true',
-			username: process.env.ACKEE_USERNAME,
-			password: process.env.ACKEE_PASSWORD,
-			isDemoMode: process.env.ACKEE_DEMO === 'true',
-			isDevelopmentMode: process.env.NODE_ENV === 'development',
-			isPreBuildMode: process.env.BUILD_ENV === 'pre',
+			ttl: configValueFromEnv('ACKEE_TTL') || day,
+			port: configValueFromEnv('ACKEE_PORT', 'PORT') || 3000,
+			dbUrl: configValueFromEnv('ACKEE_MONGODB', 'MONGODB_URI'),
+			allowOrigin: configValueFromEnv('ACKEE_ALLOW_ORIGIN'),
+			autoOrigin: configValueFromEnv('ACKEE_AUTO_ORIGIN') === 'true',
+			username: configValueFromEnv('ACKEE_USERNAME'),
+			password: configValueFromEnv('ACKEE_PASSWORD'),
+			isDemoMode: configValueFromEnv('ACKEE_DEMO') === 'true',
+			isDevelopmentMode: configValueFromEnv('NODE_ENV') === 'development',
+			isPreBuildMode: configValueFromEnv('BUILD_ENV') === 'pre',
 		}
-
 		return data[prop]
 	},
-})
+},
+)
+
+// Retrieves value of the environment variable, if it exists. We also check for
+// another enviroment variable with the same name as the but with the suffix
+// _FILE. If it exists, we read the value from the file and return it. This is
+// useful for Docker secrets.
+const configValueFromEnv = (...envVariable) => {
+	for (const env of envVariable) {
+		if (process.env[env]) {
+			return process.env[env]
+		}
+
+		const envFile = process.env[`${ env }_FILE`]
+		if (envFile) {
+			return fs.readFileSync(envFile, 'utf8')
+		}
+	}
+
+	return
+}