✨ Add support for "_FILE" environment variables

packages/cli/README.md

@@ -74,6 +74,11 @@ By default n8n uses SQLite to save credentials, past executions and workflows.
 n8n however also supports MongoDB and PostgresDB. To use them simply a few
 environment variables have to be set.
 
+To avoid passing sensitive information via environment variables "_FILE" may be
+appended to the database environment variables (for example "DB_POSTGRESDB_PASSWORD_FILE").
+It will then load the data from a file with the given name. That makes it possible to
+load data easily from Docker- and Kubernetes-Secrets.
+
 
 #### Start with MongoDB as Database
 

packages/cli/src/Db.ts

@@ -1,4 +1,5 @@
 import {
+	GenericHelpers,
 	IDatabaseCollections,
 	DatabaseType,
 } from './';
@@ -31,7 +32,7 @@ export let collections: IDatabaseCollections = {
 import * as path from 'path';
 
 export async function init(): Promise<IDatabaseCollections> {
-	const dbType = config.get('database.type') as DatabaseType;
+	const dbType = await GenericHelpers.getConfigValue('database.type') as DatabaseType;
 	const n8nFolder = UserSettings.getUserN8nFolderPath();
 
 	let entities;
@@ -41,18 +42,18 @@ export async function init(): Promise<IDatabaseCollections> {
 		entities = MongoDb;
 		connectionOptions = {
 			type: 'mongodb',
-			url: config.get('database.mongodb.connectionUrl') as string,
+			url: await GenericHelpers.getConfigValue('database.mongodb.connectionUrl') as string,
 			useNewUrlParser: true,
 		};
 	} else if (dbType === 'postgresdb') {
 		entities = PostgresDb;
 		connectionOptions = {
 			type: 'postgres',
-			database: config.get('database.postgresdb.database'),
-			host: config.get('database.postgresdb.host'),
-			password: config.get('database.postgresdb.password'),
-			port: config.get('database.postgresdb.port'),
-			username: config.get('database.postgresdb.user'),
+			database: await GenericHelpers.getConfigValue('database.postgresdb.database') as string,
+			host: await GenericHelpers.getConfigValue('database.postgresdb.host') as string,
+			password: await GenericHelpers.getConfigValue('database.postgresdb.password') as string,
+			port: await GenericHelpers.getConfigValue('database.postgresdb.port') as number,
+			username: await GenericHelpers.getConfigValue('database.postgresdb.user') as string,
 		};
 	} else if (dbType === 'sqlite') {
 		entities = SQLite;

packages/cli/src/GenericHelpers.ts

@@ -1,6 +1,12 @@
 import * as config from '../config';
 import * as express from 'express';
+import {
+	readFile as fsReadFile,
+} from 'fs';
+import { promisify } from "util";
+import { IDataObject } from 'n8n-workflow';
 
+const fsReadFileAsync = promisify(fsReadFile);
 
 /**
  * Displays a message to the user
@@ -46,3 +52,54 @@ export function getBaseUrl(): string {
 export function getSessionId(req: express.Request): string | undefined {
 	return req.headers.sessionid as string | undefined;
 }
+
+
+/**
+ * Gets value from config with support for "_FILE" environment variables
+ *
+ * @export
+ * @param {string} configKey The key of the config data to get
+ * @returns {(Promise<string | boolean | number | undefined>)}
+ */
+export async function getConfigValue(configKey: string): Promise<string | boolean | number | undefined> {
+	const configKeyParts = configKey.split('.');
+
+	// Get the environment variable
+	const configSchema = config.getSchema();
+	let currentSchema = configSchema.properties as IDataObject;
+	for (const key of configKeyParts) {
+		if (currentSchema[key] === undefined) {
+			throw new Error(`Key "${key}" of ConfigKey "${configKey}" does not exist`);
+		} else if ((currentSchema[key]! as IDataObject).properties === undefined) {
+			currentSchema = currentSchema[key] as IDataObject;
+		} else {
+			currentSchema = (currentSchema[key] as IDataObject).properties as IDataObject;
+		}
+	}
+
+	// Check if environment variable is defined for config key
+	if (currentSchema.env === undefined) {
+		// No environment variable defined, so return value from config
+		return config.get(configKey);
+	}
+
+	// Check if special file enviroment variable exists
+	const fileEnvironmentVariable = process.env[currentSchema.env + '_FILE'];
+	if (fileEnvironmentVariable === undefined) {
+		// Does not exist, so return value from config
+		return config.get(configKey);
+	}
+
+	let data;
+	try {
+		data = await fsReadFileAsync(fileEnvironmentVariable, 'utf8') as string;
+	} catch (error) {
+		if (error.code === 'ENOENT') {
+			throw new Error(`The file "${fileEnvironmentVariable}" could not be found.`);
+		}
+
+		throw error;
+	}
+
+	return data;
+}