Removes the need of a config file and allows db config via environment

backend/index.js

@@ -2,7 +2,10 @@
 
 const logger = require('./logger').global;
 
-function appStart () {
+async function appStart () {
+	// Create config file db settings if environment variables have been set
+	await createDbConfigFromEnvironment();
+
 	const migrate             = require('./migrate');
 	const setup               = require('./setup');
 	const app                 = require('./app');
@@ -10,6 +13,7 @@ function appStart () {
 	const internalCertificate = require('./internal/certificate');
 	const internalIpRanges    = require('./internal/ip_ranges');
 
+
 	return migrate.latest()
 		.then(setup)
 		.then(() => {
@@ -39,6 +43,87 @@ function appStart () {
 		});
 }
 
+async function createDbConfigFromEnvironment(){
+	return new Promise((resolve, reject) => {
+		const envMysqlHost  = process.env.DB_MYSQL_HOST;
+		const envMysqlPort  = process.env.DB_MYSQL_PORT;
+		const envMysqlUser  = process.env.DB_MYSQL_USER;
+		const envMysqlName  = process.env.DB_MYSQL_NAME;
+		const envSqliteFile = process.env.DB_SQLITE_FILE;
+		if ((envMysqlHost && envMysqlPort && envMysqlUser && envMysqlName) || envSqliteFile) {
+			const fs       = require('fs');
+			const filename = (process.env.NODE_CONFIG_DIR || './config') + '/' + (process.env.NODE_ENV || 'default') + '.json';
+			let configData = {};
+
+			try {
+				configData = require(filename);
+			} catch (err) {
+				// do nothing
+			}
+
+			if (configData.database && configData.database.engine && !configData.database.fromEnv) {
+				logger.info('Manual db configuration already exists, skipping config creation from environment variables');
+				resolve();
+				return;
+			}
+
+			if (envMysqlHost && envMysqlPort && envMysqlUser && envMysqlName) {
+				const newConfig = {
+					fromEnv:  true,
+					engine:   'mysql',
+					host:     envMysqlHost,
+					port:     envMysqlPort,
+					user:     envMysqlUser,
+					password: process.env.DB_MYSQL_PASSWORD,
+					name:     envMysqlName,
+				};
+
+				if (JSON.stringify(configData.database) === JSON.stringify(newConfig)) {
+					// Config is unchanged, skip overwrite
+					resolve();
+					return;
+				}
+
+				logger.info('Generating MySQL db configuration from environment variables');
+				configData.database = newConfig;
+
+			} else {
+				const newConfig = {
+					fromEnv: true,
+					engine:  'knex-native',
+					knex:    {
+						client:     'sqlite3',
+						connection: {
+							filename: envSqliteFile
+						}
+					}
+				};
+				if (JSON.stringify(configData.database) === JSON.stringify(newConfig)) {
+					// Config is unchanged, skip overwrite
+					resolve();
+					return;
+				}
+
+				logger.info('Generating Sqlite db configuration from environment variables');
+				configData.database = newConfig;
+			}
+
+			// Write config
+			fs.writeFile(filename, JSON.stringify(configData, null, 2), (err) => {
+				if (err) {
+					logger.error('Could not write db config to config file: ' + filename);
+					reject(err);
+				} else {
+					logger.info('Wrote db configuration to config file: ' + filename);
+					resolve();
+				}
+			});
+		} else {
+			// resolve();
+		}
+	});
+}
+
 try {
 	appStart();
 } catch (err) {