From 8c2b76e45fd930d755e3c4a48f31be237c14e77b Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Tue, 20 Oct 2020 13:08:05 +0200
Subject: [PATCH 1/8] config-loader: switch to using --config options to load
 in config

---
 .changeset/dull-icons-share.md                |  21 ++++
 packages/backend-common/package.json          |   2 +
 packages/backend-common/src/config.ts         |  12 +-
 packages/backend/src/index.ts                 |   5 +-
 packages/cli/src/commands/app/build.ts        |  16 +--
 packages/cli/src/commands/app/serve.ts        |  16 +--
 packages/cli/src/commands/backend/dev.ts      |  14 ---
 packages/cli/src/commands/config/print.ts     |  17 +--
 packages/cli/src/commands/index.ts            |  18 ++-
 packages/cli/src/commands/plugin/export.ts    |  16 +--
 packages/cli/src/commands/plugin/serve.ts     |  16 +--
 packages/cli/src/lib/bundler/backend.ts       |   8 +-
 packages/cli/src/lib/bundler/types.ts         |  16 ++-
 packages/cli/src/lib/config.ts                |  42 +++++++
 packages/config-loader/src/lib/index.ts       |   1 -
 .../config-loader/src/lib/resolver.test.ts    | 119 ------------------
 packages/config-loader/src/lib/resolver.ts    |  59 ---------
 packages/config-loader/src/loader.test.ts     |  38 +++++-
 packages/config-loader/src/loader.ts          |  44 +++++--
 .../default-app/packages/backend/src/index.ts |   2 +-
 .../src/service/standaloneServer.ts           |   2 +-
 .../src/service/standaloneServer.ts           |   2 +-
 .../proxy-backend/src/service/router.test.ts  |   2 +-
 .../src/service/standaloneServer.ts           |   2 +-
 .../src/service/standaloneServer.ts           |   2 +-
 .../techdocs-backend/src/default-branch.ts    |   5 +-
 yarn.lock                                     |   5 +
 27 files changed, 200 insertions(+), 302 deletions(-)
 create mode 100644 .changeset/dull-icons-share.md
 create mode 100644 packages/cli/src/lib/config.ts
 delete mode 100644 packages/config-loader/src/lib/resolver.test.ts
 delete mode 100644 packages/config-loader/src/lib/resolver.ts

diff --git a/.changeset/dull-icons-share.md b/.changeset/dull-icons-share.md
new file mode 100644
index 0000000000..aa4c01e422
--- /dev/null
+++ b/.changeset/dull-icons-share.md
@@ -0,0 +1,21 @@
+---
+'@backstage/backend-common': minor
+'@backstage/cli': minor
+'@backstage/config-loader': minor
+'example-backend': patch
+'@backstage/create-app': patch
+---
+
+**BREAKING CHANGE**
+
+The existing loading of additional config files like `app-config.development.yaml` using APP_ENV or NODE_ENV has been removed.
+Instead, the CLI and backend process now accept one or more `--config` flags to load config files.
+
+Without passing any flags, `app-config.yaml` and, if it exists, `app-config.local.yaml` will be loaded.
+If passing any `--config <path>` flags, only those files will be loaded, **NOT** the default `app-config.yaml` one.
+
+The old behaviour of for example `APP_ENV=development` can be replicated using the following flags:
+
+```bash
+--config ../../app-config.yaml --config ../../app-config.development.yaml
+```
diff --git a/packages/backend-common/package.json b/packages/backend-common/package.json
index 249fa9e72c..50880a1228 100644
--- a/packages/backend-common/package.json
+++ b/packages/backend-common/package.json
@@ -44,6 +44,7 @@
     "knex": "^0.21.1",
     "lodash": "^4.17.15",
     "logform": "^2.1.1",
+    "minimist": "^1.2.5",
     "morgan": "^1.10.0",
     "node-fetch": "^2.6.0",
     "prom-client": "^12.0.0",
@@ -63,6 +64,7 @@
     "@backstage/cli": "^0.1.1-alpha.25",
     "@types/compression": "^1.7.0",
     "@types/http-errors": "^1.6.3",
+    "@types/minimist": "^1.2.0",
     "@types/morgan": "^1.9.0",
     "@types/node-fetch": "^2.5.7",
     "@types/stoppable": "^1.1.0",
diff --git a/packages/backend-common/src/config.ts b/packages/backend-common/src/config.ts
index c86793fc08..6223d3150b 100644
--- a/packages/backend-common/src/config.ts
+++ b/packages/backend-common/src/config.ts
@@ -14,24 +14,32 @@
  * limitations under the License.
  */
 
+import { resolve as resolvePath } from 'path';
+import parseArgs from 'minimist';
+import { Logger } from 'winston';
 import { findPaths } from '@backstage/cli-common';
 import { Config, ConfigReader } from '@backstage/config';
 import { loadConfig } from '@backstage/config-loader';
-import { Logger } from 'winston';
 
 type Options = {
   logger: Logger;
+  // process.argv or any other overrides
+  argv: string[];
 };
 
 /**
  * Load configuration for a Backend
  */
 export async function loadBackendConfig(options: Options): Promise<Config> {
+  const args = parseArgs(options.argv);
+  const configOpts: string[] = args.config ?? [];
+
   /* eslint-disable-next-line no-restricted-syntax */
   const paths = findPaths(__dirname);
   const configs = await loadConfig({
     env: process.env.APP_ENV ?? process.env.NODE_ENV ?? 'development',
-    rootPaths: [paths.targetRoot, paths.targetDir],
+    configRoot: paths.targetRoot,
+    configPaths: configOpts.map(opt => resolvePath(opt)),
     shouldReadSecrets: true,
   });
 
diff --git a/packages/backend/src/index.ts b/packages/backend/src/index.ts
index cbeaf4315c..b74954ecc5 100644
--- a/packages/backend/src/index.ts
+++ b/packages/backend/src/index.ts
@@ -64,7 +64,10 @@ function makeCreateEnv(config: Config) {
 }
 
 async function main() {
-  const config = await loadBackendConfig({ logger: getRootLogger() });
+  const config = await loadBackendConfig({
+    argv: process.argv,
+    logger: getRootLogger(),
+  });
   const createEnv = makeCreateEnv(config);
 
   const healthcheckEnv = useHotMemoize(module, () => createEnv('healthcheck'));
diff --git a/packages/cli/src/commands/app/build.ts b/packages/cli/src/commands/app/build.ts
index 5a9d2cdf3a..c5f5f5aa2f 100644
--- a/packages/cli/src/commands/app/build.ts
+++ b/packages/cli/src/commands/app/build.ts
@@ -15,27 +15,15 @@
  */
 
 import { Command } from 'commander';
-import { loadConfig } from '@backstage/config-loader';
-import { ConfigReader } from '@backstage/config';
-import { paths } from '../../lib/paths';
 import { buildBundle } from '../../lib/bundler';
 import { parseParallel, PARALLEL_ENV_VAR } from '../../lib/parallel';
+import { loadCliConfig } from '../../lib/config';
 
 export default async (cmd: Command) => {
-  const appConfigs = await loadConfig({
-    env: process.env.APP_ENV ?? process.env.NODE_ENV ?? 'production',
-    rootPaths: [paths.targetRoot, paths.targetDir],
-  });
-
-  console.log(
-    `Loaded config from ${appConfigs.map(c => c.context).join(', ')}`,
-  );
-
   await buildBundle({
     entry: 'src/index',
     parallel: parseParallel(process.env[PARALLEL_ENV_VAR]),
     statsJsonEnabled: cmd.stats,
-    config: ConfigReader.fromConfigs(appConfigs),
-    appConfigs,
+    ...(await loadCliConfig(cmd.config)),
   });
 };
diff --git a/packages/cli/src/commands/app/serve.ts b/packages/cli/src/commands/app/serve.ts
index 6524eb3acf..c3f58774b5 100644
--- a/packages/cli/src/commands/app/serve.ts
+++ b/packages/cli/src/commands/app/serve.ts
@@ -15,26 +15,14 @@
  */
 
 import { Command } from 'commander';
-import { loadConfig } from '@backstage/config-loader';
-import { ConfigReader } from '@backstage/config';
-import { paths } from '../../lib/paths';
 import { serveBundle } from '../../lib/bundler';
+import { loadCliConfig } from '../../lib/config';
 
 export default async (cmd: Command) => {
-  const appConfigs = await loadConfig({
-    env: process.env.APP_ENV ?? process.env.NODE_ENV ?? 'development',
-    rootPaths: [paths.targetRoot, paths.targetDir],
-  });
-
-  console.log(
-    `Loaded config from ${appConfigs.map(c => c.context).join(', ')}`,
-  );
-
   const waitForExit = await serveBundle({
     entry: 'src/index',
     checksEnabled: cmd.check,
-    config: ConfigReader.fromConfigs(appConfigs),
-    appConfigs,
+    ...(await loadCliConfig(cmd.config)),
   });
 
   await waitForExit();
diff --git a/packages/cli/src/commands/backend/dev.ts b/packages/cli/src/commands/backend/dev.ts
index d7b5ca2924..88c069a92b 100644
--- a/packages/cli/src/commands/backend/dev.ts
+++ b/packages/cli/src/commands/backend/dev.ts
@@ -14,28 +14,14 @@
  * limitations under the License.
  */
 
-import { ConfigReader } from '@backstage/config';
-import { loadConfig } from '@backstage/config-loader';
 import { Command } from 'commander';
-import { paths } from '../../lib/paths';
 import { serveBackend } from '../../lib/bundler/backend';
 
 export default async (cmd: Command) => {
-  const appConfigs = await loadConfig({
-    env: process.env.APP_ENV ?? process.env.NODE_ENV ?? 'development',
-    rootPaths: [paths.targetRoot, paths.targetDir],
-  });
-
-  console.log(
-    `Loaded config from ${appConfigs.map(c => c.context).join(', ')}`,
-  );
-
   const waitForExit = await serveBackend({
     entry: 'src/index',
     checksEnabled: cmd.check,
     inspectEnabled: cmd.inspect,
-    config: ConfigReader.fromConfigs(appConfigs),
-    appConfigs,
   });
 
   await waitForExit();
diff --git a/packages/cli/src/commands/config/print.ts b/packages/cli/src/commands/config/print.ts
index 693724e4d9..eb814a5bee 100644
--- a/packages/cli/src/commands/config/print.ts
+++ b/packages/cli/src/commands/config/print.ts
@@ -15,24 +15,13 @@
  */
 
 import { Command } from 'commander';
-import { loadConfig } from '@backstage/config-loader';
-import { ConfigReader } from '@backstage/config';
-import { paths } from '../../lib/paths';
 import { stringify as stringifyYaml } from 'yaml';
+import { loadCliConfig } from '../../lib/config';
 
 export default async (cmd: Command) => {
-  const appConfigs = await loadConfig({
-    env:
-      cmd.env ?? process.env.APP_ENV ?? process.env.NODE_ENV ?? 'development',
-    shouldReadSecrets: cmd.withSecrets ?? false,
-    rootPaths: [paths.targetRoot, paths.targetDir],
-  });
+  const { config } = await loadCliConfig(cmd.config, cmd.withSecrets ?? false);
 
-  console.log(
-    `Loaded config from ${appConfigs.map(c => c.context).join(', ')}`,
-  );
-
-  const flatConfig = ConfigReader.fromConfigs(appConfigs).get();
+  const flatConfig = config.get();
 
   if (cmd.format === 'json') {
     process.stdout.write(`${JSON.stringify(flatConfig, null, 2)}\n`);
diff --git a/packages/cli/src/commands/index.ts b/packages/cli/src/commands/index.ts
index e5017b829a..7f028919f7 100644
--- a/packages/cli/src/commands/index.ts
+++ b/packages/cli/src/commands/index.ts
@@ -18,16 +18,25 @@ import { CommanderStatic } from 'commander';
 import { exitWithError } from '../lib/errors';
 
 export function registerCommands(program: CommanderStatic) {
+  const configOption = [
+    '--config <path>',
+    'Config files to load instead of app-config.yaml',
+    (opt: string, opts: string[]) => [...opts, opt],
+    Array<string>(),
+  ] as const;
+
   program
     .command('app:build')
     .description('Build an app for a production release')
     .option('--stats', 'Write bundle stats to output directory')
+    .option(...configOption)
     .action(lazy(() => import('./app/build').then(m => m.default)));
 
   program
     .command('app:serve')
     .description('Serve an app for local development')
     .option('--check', 'Enable type checking and linting')
+    .option(...configOption)
     .action(lazy(() => import('./app/serve').then(m => m.default)));
 
   program
@@ -50,6 +59,8 @@ export function registerCommands(program: CommanderStatic) {
     .description('Start local development server with HMR for the backend')
     .option('--check', 'Enable type checking and linting')
     .option('--inspect', 'Enable debugger')
+    // We don't actually use the config in the CLI, just pass them on to the NodeJS process
+    .option(...configOption)
     .action(lazy(() => import('./backend/dev').then(m => m.default)));
 
   program
@@ -89,12 +100,14 @@ export function registerCommands(program: CommanderStatic) {
     .command('plugin:serve')
     .description('Serves the dev/ folder of a plugin')
     .option('--check', 'Enable type checking and linting')
+    .option(...configOption)
     .action(lazy(() => import('./plugin/serve').then(m => m.default)));
 
   program
     .command('plugin:export')
     .description('Exports the dev/ folder of a plugin')
     .option('--stats', 'Write bundle stats to output directory')
+    .option(...configOption)
     .action(lazy(() => import('./plugin/export').then(m => m.default)));
 
   program
@@ -131,14 +144,11 @@ export function registerCommands(program: CommanderStatic) {
   program
     .command('config:print')
     .option('--with-secrets', 'Include secrets in the printed configuration')
-    .option(
-      '--env <env>',
-      'The environment to print configuration for [APP_ENV or NODE_ENV or development]',
-    )
     .option(
       '--format <format>',
       'Format to print the configuration in, either json or yaml [yaml]',
     )
+    .option(...configOption)
     .description('Print the app configuration for the current package')
     .action(lazy(() => import('./config/print').then(m => m.default)));
 
diff --git a/packages/cli/src/commands/plugin/export.ts b/packages/cli/src/commands/plugin/export.ts
index 39865f3d32..69955a2e5f 100644
--- a/packages/cli/src/commands/plugin/export.ts
+++ b/packages/cli/src/commands/plugin/export.ts
@@ -15,25 +15,13 @@
  */
 
 import { Command } from 'commander';
-import { loadConfig } from '@backstage/config-loader';
-import { ConfigReader } from '@backstage/config';
-import { paths } from '../../lib/paths';
 import { buildBundle } from '../../lib/bundler';
+import { loadCliConfig } from '../../lib/config';
 
 export default async (cmd: Command) => {
-  const appConfigs = await loadConfig({
-    env: process.env.APP_ENV ?? process.env.NODE_ENV ?? 'production',
-    rootPaths: [paths.targetRoot, paths.targetDir],
-  });
-
-  console.log(
-    `Loaded config from ${appConfigs.map(c => c.context).join(', ')}`,
-  );
-
   await buildBundle({
     entry: 'dev/index',
     statsJsonEnabled: cmd.stats,
-    config: ConfigReader.fromConfigs(appConfigs),
-    appConfigs,
+    ...(await loadCliConfig(cmd.config)),
   });
 };
diff --git a/packages/cli/src/commands/plugin/serve.ts b/packages/cli/src/commands/plugin/serve.ts
index 7c92c8f312..cb9def3158 100644
--- a/packages/cli/src/commands/plugin/serve.ts
+++ b/packages/cli/src/commands/plugin/serve.ts
@@ -15,26 +15,14 @@
  */
 
 import { Command } from 'commander';
-import { loadConfig } from '@backstage/config-loader';
-import { ConfigReader } from '@backstage/config';
-import { paths } from '../../lib/paths';
 import { serveBundle } from '../../lib/bundler';
+import { loadCliConfig } from '../../lib/config';
 
 export default async (cmd: Command) => {
-  const appConfigs = await loadConfig({
-    env: process.env.APP_ENV ?? process.env.NODE_ENV ?? 'development',
-    rootPaths: [paths.targetRoot, paths.targetDir],
-  });
-
-  console.log(
-    `Loaded config from ${appConfigs.map(c => c.context).join(', ')}`,
-  );
-
   const waitForExit = await serveBundle({
     entry: 'dev/index',
     checksEnabled: cmd.check,
-    config: ConfigReader.fromConfigs(appConfigs),
-    appConfigs,
+    ...(await loadCliConfig(cmd.config)),
   });
 
   await waitForExit();
diff --git a/packages/cli/src/lib/bundler/backend.ts b/packages/cli/src/lib/bundler/backend.ts
index e3cc8af8d1..9633c1b963 100644
--- a/packages/cli/src/lib/bundler/backend.ts
+++ b/packages/cli/src/lib/bundler/backend.ts
@@ -17,13 +17,9 @@
 import webpack from 'webpack';
 import { createBackendConfig } from './config';
 import { resolveBundlingPaths } from './paths';
-import { ServeOptions } from './types';
+import { BackendServeOptions } from './types';
 
-export async function serveBackend(
-  options: ServeOptions & {
-    inspectEnabled: boolean;
-  },
-) {
+export async function serveBackend(options: BackendServeOptions) {
   const paths = resolveBundlingPaths(options);
   const config = await createBackendConfig(paths, {
     ...options,
diff --git a/packages/cli/src/lib/bundler/types.ts b/packages/cli/src/lib/bundler/types.ts
index 827d517fef..00f1895725 100644
--- a/packages/cli/src/lib/bundler/types.ts
+++ b/packages/cli/src/lib/bundler/types.ts
@@ -27,10 +27,6 @@ export type BundlingOptions = {
   parallel?: ParallelOption;
 };
 
-export type BackendBundlingOptions = Omit<BundlingOptions, 'baseUrl'> & {
-  inspectEnabled: boolean;
-};
-
 export type ServeOptions = BundlingPathsOptions & {
   checksEnabled: boolean;
   config: Config;
@@ -43,3 +39,15 @@ export type BuildOptions = BundlingPathsOptions & {
   config: Config;
   appConfigs: AppConfig[];
 };
+
+export type BackendBundlingOptions = {
+  checksEnabled: boolean;
+  isDev: boolean;
+  parallel?: ParallelOption;
+  inspectEnabled: boolean;
+};
+
+export type BackendServeOptions = BundlingPathsOptions & {
+  checksEnabled: boolean;
+  inspectEnabled: boolean;
+};
diff --git a/packages/cli/src/lib/config.ts b/packages/cli/src/lib/config.ts
new file mode 100644
index 0000000000..5801632ea5
--- /dev/null
+++ b/packages/cli/src/lib/config.ts
@@ -0,0 +1,42 @@
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { loadConfig } from '@backstage/config-loader';
+import { ConfigReader } from '@backstage/config';
+import { paths } from './paths';
+
+export async function loadCliConfig(
+  configArgs: string[],
+  shouldReadSecrets: boolean = false,
+) {
+  const configPaths = configArgs.map(arg => paths.resolveTarget(arg));
+
+  const appConfigs = await loadConfig({
+    shouldReadSecrets,
+    env: process.env.APP_ENV ?? process.env.NODE_ENV ?? 'production',
+    configRoot: paths.targetRoot,
+    configPaths,
+  });
+
+  console.log(
+    `Loaded config from ${appConfigs.map(c => c.context).join(', ')}`,
+  );
+
+  return {
+    appConfigs,
+    config: ConfigReader.fromConfigs(appConfigs),
+  };
+}
diff --git a/packages/config-loader/src/lib/index.ts b/packages/config-loader/src/lib/index.ts
index 40252b9cec..1b5ad2ef50 100644
--- a/packages/config-loader/src/lib/index.ts
+++ b/packages/config-loader/src/lib/index.ts
@@ -14,7 +14,6 @@
  * limitations under the License.
  */
 
-export { resolveStaticConfig } from './resolver';
 export { readConfigFile } from './reader';
 export { readEnvConfig } from './env';
 export { readSecret } from './secrets';
diff --git a/packages/config-loader/src/lib/resolver.test.ts b/packages/config-loader/src/lib/resolver.test.ts
deleted file mode 100644
index 9fd71f2486..0000000000
--- a/packages/config-loader/src/lib/resolver.test.ts
+++ /dev/null
@@ -1,119 +0,0 @@
-/*
- * Copyright 2020 Spotify AB
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-import mockFs from 'mock-fs';
-import { resolveStaticConfig } from './resolver';
-
-function normalizePaths(paths: string[]) {
-  return paths.map(p =>
-    p
-      .replace(/^[a-z]:/i, '')
-      .split('\\')
-      .join('/'),
-  );
-}
-
-describe('resolveStaticConfig', () => {
-  afterEach(() => {
-    mockFs.restore();
-  });
-
-  it('should resolve no files for empty roots', async () => {
-    mockFs({});
-    const resolved = await resolveStaticConfig({
-      env: 'development',
-      rootPaths: [],
-    });
-
-    expect(normalizePaths(resolved)).toEqual([]);
-  });
-
-  it('should resolve a single app-config', async () => {
-    mockFs({ '/repo/app-config.yaml': '' });
-    const resolved = await resolveStaticConfig({
-      env: 'development',
-      rootPaths: ['/repo'],
-    });
-
-    expect(normalizePaths(resolved)).toEqual(['/repo/app-config.yaml']);
-  });
-
-  it('should resolve a app-configs in different directories', async () => {
-    mockFs({
-      '/repo/app-config.yaml': '',
-      '/repo/packages/a/app-config.yaml': '',
-    });
-    const resolved = await resolveStaticConfig({
-      env: 'development',
-      rootPaths: [
-        '/repo',
-        '/other-repo',
-        '/repo/packages/a',
-        '/repo/packages/b',
-      ],
-    });
-
-    expect(normalizePaths(resolved)).toEqual([
-      '/repo/app-config.yaml',
-      '/repo/packages/a/app-config.yaml',
-    ]);
-  });
-
-  it('should resolve env and local configs', async () => {
-    mockFs({
-      '/repo/app-config.yaml': '',
-      '/repo/app-config.local.yaml': '',
-      '/repo/app-config.production.yaml': '',
-      '/repo/app-config.production.local.yaml': '',
-      '/repo/app-config.development.local.yaml': '',
-      '/repo/packages/a/app-config.development.yaml': '',
-      '/repo/packages/a/app-config.local.yaml': '',
-    });
-    const resolved = await resolveStaticConfig({
-      env: 'development',
-      rootPaths: ['/repo', '/repo/packages/a'],
-    });
-
-    expect(normalizePaths(resolved)).toEqual([
-      '/repo/app-config.yaml',
-      '/repo/app-config.local.yaml',
-      '/repo/app-config.development.local.yaml',
-      '/repo/packages/a/app-config.local.yaml',
-      '/repo/packages/a/app-config.development.yaml',
-    ]);
-  });
-
-  it('resolves suffixed configs in the correct order', async () => {
-    mockFs({
-      '/repo/app-config.yaml': '',
-      '/repo/app-config.local.yaml': '',
-      '/repo/app-config.production.yaml': '',
-      '/repo/app-config.production.local.yaml': '',
-    });
-
-    const resolved = await resolveStaticConfig({
-      env: 'production',
-      rootPaths: ['/repo'],
-    });
-
-    expect(normalizePaths(resolved)).toEqual([
-      '/repo/app-config.yaml',
-      '/repo/app-config.local.yaml',
-      '/repo/app-config.production.yaml',
-      '/repo/app-config.production.local.yaml',
-    ]);
-  });
-});
diff --git a/packages/config-loader/src/lib/resolver.ts b/packages/config-loader/src/lib/resolver.ts
deleted file mode 100644
index 3856598331..0000000000
--- a/packages/config-loader/src/lib/resolver.ts
+++ /dev/null
@@ -1,59 +0,0 @@
-/*
- * Copyright 2020 Spotify AB
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-import { resolve as resolvePath } from 'path';
-import { pathExists } from 'fs-extra';
-
-type ResolveOptions = {
-  // Root paths to search for config files. Config from earlier paths has lower priority.
-  rootPaths: string[];
-  // The environment that we're loading config for, e.g. 'development', 'production'.
-  env: string;
-};
-
-/**
- * Resolves all configuration files that should be loaded in the given environment.
- *
- * For each root directory, search for the default app-config.yaml, along with suffixed
- * APP_ENV and local variants, e.g. app-config.production.yaml or app-config.development.local.yaml
- *
- * The priority order of config loaded through suffixes is `env > local > none`, meaning that
- * for example app-config.development.yaml has higher priority than `app-config.local.yaml`.
- *
- */
-export async function resolveStaticConfig(
-  options: ResolveOptions,
-): Promise<string[]> {
-  const filePaths = [
-    `app-config.yaml`,
-    `app-config.local.yaml`,
-    `app-config.${options.env}.yaml`,
-    `app-config.${options.env}.local.yaml`,
-  ];
-
-  const resolvedPaths = [];
-
-  for (const rootPath of options.rootPaths) {
-    for (const filePath of filePaths) {
-      const path = resolvePath(rootPath, filePath);
-      if (await pathExists(path)) {
-        resolvedPaths.push(path);
-      }
-    }
-  }
-
-  return resolvedPaths;
-}
diff --git a/packages/config-loader/src/loader.test.ts b/packages/config-loader/src/loader.test.ts
index 087e2309c0..3b0d8e6e92 100644
--- a/packages/config-loader/src/loader.test.ts
+++ b/packages/config-loader/src/loader.test.ts
@@ -38,10 +38,31 @@ describe('loadConfig', () => {
     mockFs.restore();
   });
 
+  it('load config from default path', async () => {
+    await expect(
+      loadConfig({
+        configRoot: '/root',
+        configPaths: [],
+        env: 'production',
+        shouldReadSecrets: false,
+      }),
+    ).resolves.toEqual([
+      {
+        context: 'app-config.yaml',
+        data: {
+          app: {
+            title: 'Example App',
+          },
+        },
+      },
+    ]);
+  });
+
   it('loads config without secrets', async () => {
     await expect(
       loadConfig({
-        rootPaths: ['/root'],
+        configRoot: '/root',
+        configPaths: ['/root/app-config.yaml'],
         env: 'production',
         shouldReadSecrets: false,
       }),
@@ -60,7 +81,8 @@ describe('loadConfig', () => {
   it('loads config with secrets', async () => {
     await expect(
       loadConfig({
-        rootPaths: ['/root'],
+        configRoot: '/root',
+        configPaths: ['/root/app-config.yaml'],
         env: 'production',
         shouldReadSecrets: true,
       }),
@@ -80,7 +102,11 @@ describe('loadConfig', () => {
   it('loads development config without secrets', async () => {
     await expect(
       loadConfig({
-        rootPaths: ['/root'],
+        configRoot: '/root',
+        configPaths: [
+          '/root/app-config.yaml',
+          '/root/app-config.development.yaml',
+        ],
         env: 'development',
         shouldReadSecrets: false,
       }),
@@ -105,7 +131,11 @@ describe('loadConfig', () => {
   it('loads development config with secrets', async () => {
     await expect(
       loadConfig({
-        rootPaths: ['/root'],
+        configRoot: '/root',
+        configPaths: [
+          '/root/app-config.yaml',
+          '/root/app-config.development.yaml',
+        ],
         env: 'development',
         shouldReadSecrets: true,
       }),
diff --git a/packages/config-loader/src/loader.ts b/packages/config-loader/src/loader.ts
index cf5edd3ce3..e7eb2a38fa 100644
--- a/packages/config-loader/src/loader.ts
+++ b/packages/config-loader/src/loader.ts
@@ -15,20 +15,18 @@
  */
 
 import fs from 'fs-extra';
-import { resolve as resolvePath, dirname } from 'path';
+import { resolve as resolvePath, dirname, isAbsolute } from 'path';
 import { AppConfig, JsonObject } from '@backstage/config';
-import {
-  resolveStaticConfig,
-  readConfigFile,
-  readEnvConfig,
-  readSecret,
-} from './lib';
+import { readConfigFile, readEnvConfig, readSecret } from './lib';
 
 export type LoadConfigOptions = {
-  // Root paths to search for config files. Config from earlier paths has lower priority.
-  rootPaths: string[];
+  // The root directory of the config loading context. Used to find default configs.
+  configRoot: string;
 
-  // The environment that we're loading config for, e.g. 'development', 'production'.
+  // Absolute paths to load config files from. Configs from earlier paths have lower priority.
+  configPaths: string[];
+
+  // TODO(Rugvip): This will be removed in the future, but for now we use it to warn about possible mistakes.
   env: string;
 
   // Whether to read secrets or omit them, defaults to false.
@@ -77,13 +75,37 @@ export async function loadConfig(
   options: LoadConfigOptions,
 ): Promise<AppConfig[]> {
   const configs = [];
+  const { configRoot } = options;
+  const configPaths = options.configPaths.slice();
 
-  const configPaths = await resolveStaticConfig(options);
+  // If no paths are provided, we default to reading
+  // `app-config.yaml` and, if it exists, `app-config.local.yaml`
+  if (configPaths.length === 0) {
+    configPaths.push(resolvePath(configRoot, 'app-config.yaml'));
+
+    const localConfig = resolvePath(configRoot, 'app-config.local.yaml');
+    if (await fs.pathExists(localConfig)) {
+      configPaths.push(localConfig);
+    }
+
+    const envFile = `app-config.${options.env}.yaml`;
+    if (await fs.pathExists(resolvePath(configRoot, envFile))) {
+      console.error(
+        `Env config file '${envFile}' is not loaded as APP_ENV and NODE_ENV-based config loading has been removed`,
+      );
+      console.error(
+        `To load the config file, use --config <path>, listing every config file that you want to load`,
+      );
+    }
+  }
 
   try {
     const secretPaths = new Set<string>();
 
     for (const configPath of configPaths) {
+      if (!isAbsolute(configPath)) {
+        throw new Error(`Config load path is not absolute: '${configPath}'`);
+      }
       const config = await readConfigFile(
         configPath,
         new Context({
diff --git a/packages/create-app/templates/default-app/packages/backend/src/index.ts b/packages/create-app/templates/default-app/packages/backend/src/index.ts
index 18b6cfa647..e5cfc31576 100644
--- a/packages/create-app/templates/default-app/packages/backend/src/index.ts
+++ b/packages/create-app/templates/default-app/packages/backend/src/index.ts
@@ -42,7 +42,7 @@ function makeCreateEnv(config: Config) {
 }
 
 async function main() {
-  const config = await loadBackendConfig({logger: getRootLogger()});
+  const config = await loadBackendConfig({logger: getRootLogger(), configPaths: []});
   const createEnv = makeCreateEnv(config);
 
   const catalogEnv = useHotMemoize(module, () => createEnv('catalog'));
diff --git a/plugins/auth-backend/src/service/standaloneServer.ts b/plugins/auth-backend/src/service/standaloneServer.ts
index a3c64c6e8e..a4f2377507 100644
--- a/plugins/auth-backend/src/service/standaloneServer.ts
+++ b/plugins/auth-backend/src/service/standaloneServer.ts
@@ -33,7 +33,7 @@ export async function startStandaloneServer(
   options: ServerOptions,
 ): Promise<Server> {
   const logger = options.logger.child({ service: 'auth-backend' });
-  const config = await loadBackendConfig({ logger });
+  const config = await loadBackendConfig({ logger, argv: process.argv });
   const discovery = SingleHostDiscovery.fromConfig(config);
 
   const database = useHotMemoize(module, () => {
diff --git a/plugins/catalog-backend/src/service/standaloneServer.ts b/plugins/catalog-backend/src/service/standaloneServer.ts
index 23f9795036..73a33c8c8e 100644
--- a/plugins/catalog-backend/src/service/standaloneServer.ts
+++ b/plugins/catalog-backend/src/service/standaloneServer.ts
@@ -36,7 +36,7 @@ export async function startStandaloneServer(
   options: ServerOptions,
 ): Promise<Server> {
   const logger = options.logger.child({ service: 'catalog-backend' });
-  const config = await loadBackendConfig({ logger });
+  const config = await loadBackendConfig({ logger, argv: process.argv });
   const reader = UrlReaders.default({ logger, config });
   const db = useHotMemoize(module, () =>
     DatabaseManager.createInMemoryDatabaseConnection(),
diff --git a/plugins/proxy-backend/src/service/router.test.ts b/plugins/proxy-backend/src/service/router.test.ts
index 42e723e54a..77db35c917 100644
--- a/plugins/proxy-backend/src/service/router.test.ts
+++ b/plugins/proxy-backend/src/service/router.test.ts
@@ -41,7 +41,7 @@ const mockCreateProxyMiddleware = createProxyMiddleware as jest.MockedFunction<
 describe('createRouter', () => {
   it('works', async () => {
     const logger = winston.createLogger();
-    const config = await loadBackendConfig({ logger });
+    const config = await loadBackendConfig({ logger, argv: [] });
     const discovery = SingleHostDiscovery.fromConfig(config);
     const router = await createRouter({
       config,
diff --git a/plugins/proxy-backend/src/service/standaloneServer.ts b/plugins/proxy-backend/src/service/standaloneServer.ts
index 160ed1db86..c64d69e2a4 100644
--- a/plugins/proxy-backend/src/service/standaloneServer.ts
+++ b/plugins/proxy-backend/src/service/standaloneServer.ts
@@ -36,7 +36,7 @@ export async function startStandaloneServer(
 
   logger.debug('Creating application...');
 
-  const config = await loadBackendConfig({ logger });
+  const config = await loadBackendConfig({ logger, argv: process.argv });
   const discovery = SingleHostDiscovery.fromConfig(config);
   const router = await createRouter({
     config,
diff --git a/plugins/rollbar-backend/src/service/standaloneServer.ts b/plugins/rollbar-backend/src/service/standaloneServer.ts
index 1be2599724..b30bf6fc6b 100644
--- a/plugins/rollbar-backend/src/service/standaloneServer.ts
+++ b/plugins/rollbar-backend/src/service/standaloneServer.ts
@@ -32,7 +32,7 @@ export async function startStandaloneServer(
   options: ServerOptions,
 ): Promise<Server> {
   const logger = options.logger.child({ service: 'rollbar-backend' });
-  const config = await loadBackendConfig({ logger });
+  const config = await loadBackendConfig({ logger, argv: process.argv });
 
   logger.debug('Creating application...');
 
diff --git a/plugins/techdocs-backend/src/default-branch.ts b/plugins/techdocs-backend/src/default-branch.ts
index e9164c5175..52b8b008f9 100644
--- a/plugins/techdocs-backend/src/default-branch.ts
+++ b/plugins/techdocs-backend/src/default-branch.ts
@@ -231,7 +231,10 @@ export const getDefaultBranch = async (
   repositoryUrl: string,
 ): Promise<string> => {
   // TODO(Rugvip): Config should not be loaded here, pass it in instead
-  const config = await loadBackendConfig({ logger: getRootLogger() });
+  const config = await loadBackendConfig({
+    logger: getRootLogger(),
+    argv: process.argv,
+  });
   const type = getGitRepoType(repositoryUrl);
 
   try {
diff --git a/yarn.lock b/yarn.lock
index 0c7c8635c2..144b3c6827 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -5351,6 +5351,11 @@
   resolved "https://registry.npmjs.org/@types/minimatch/-/minimatch-3.0.3.tgz#3dca0e3f33b200fc7d1139c0cd96c1268cadfd9d"
   integrity sha512-tHq6qdbT9U1IRSGf14CL0pUlULksvY9OZ+5eEgl1N7t+OA3tGvNpxJCzuKQlsNgCVwbAs670L1vcVQi8j9HjnA==
 
+"@types/minimist@^1.2.0":
+  version "1.2.0"
+  resolved "https://registry.npmjs.org/@types/minimist/-/minimist-1.2.0.tgz#69a23a3ad29caf0097f06eda59b361ee2f0639f6"
+  integrity sha1-aaI6OtKcrwCX8G7aWbNh7i8GOfY=
+
 "@types/minipass@*":
   version "2.2.0"
   resolved "https://registry.npmjs.org/@types/minipass/-/minipass-2.2.0.tgz#51ad404e8eb1fa961f75ec61205796807b6f9651"

From fac3026699d2c7cad649456faa04a0146daa2623 Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Wed, 21 Oct 2020 10:31:02 +0200
Subject: [PATCH 2/8] create-app: prettier backend + fix loadBackendConfig arg

---
 .../default-app/packages/backend/src/index.ts   | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/packages/create-app/templates/default-app/packages/backend/src/index.ts b/packages/create-app/templates/default-app/packages/backend/src/index.ts
index e5cfc31576..51de1ad6b3 100644
--- a/packages/create-app/templates/default-app/packages/backend/src/index.ts
+++ b/packages/create-app/templates/default-app/packages/backend/src/index.ts
@@ -42,7 +42,10 @@ function makeCreateEnv(config: Config) {
 }
 
 async function main() {
-  const config = await loadBackendConfig({logger: getRootLogger(), configPaths: []});
+  const config = await loadBackendConfig({
+    argv: process.argv,
+    logger: getRootLogger(),
+  });
   const createEnv = makeCreateEnv(config);
 
   const catalogEnv = useHotMemoize(module, () => createEnv('catalog'));
@@ -52,16 +55,16 @@ async function main() {
   const techdocsEnv = useHotMemoize(module, () => createEnv('techdocs'));
 
   const apiRouter = Router();
-  apiRouter.use('/catalog', await catalog(catalogEnv))
-  apiRouter.use('/scaffolder', await scaffolder(scaffolderEnv))
-  apiRouter.use('/auth', await auth(authEnv))
-  apiRouter.use('/techdocs', await techdocs(techdocsEnv))
-  apiRouter.use('/proxy', await proxy(proxyEnv))
+  apiRouter.use('/catalog', await catalog(catalogEnv));
+  apiRouter.use('/scaffolder', await scaffolder(scaffolderEnv));
+  apiRouter.use('/auth', await auth(authEnv));
+  apiRouter.use('/techdocs', await techdocs(techdocsEnv));
+  apiRouter.use('/proxy', await proxy(proxyEnv));
   apiRouter.use(notFoundHandler());
 
   const service = createServiceBuilder(module)
     .loadConfig(config)
-    .addRouter('/api', apiRouter)
+    .addRouter('/api', apiRouter);
 
   await service.start().catch(err => {
     console.log(err);

From 4a6a5149df1db7918694fc5c2dd46b5a0cae29f1 Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Wed, 21 Oct 2020 10:49:41 +0200
Subject: [PATCH 3/8] backend-common: fix for args.config not always being an
 array

---
 packages/backend-common/src/config.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/backend-common/src/config.ts b/packages/backend-common/src/config.ts
index 6223d3150b..69e46bd5b4 100644
--- a/packages/backend-common/src/config.ts
+++ b/packages/backend-common/src/config.ts
@@ -32,7 +32,7 @@ type Options = {
  */
 export async function loadBackendConfig(options: Options): Promise<Config> {
   const args = parseArgs(options.argv);
-  const configOpts: string[] = args.config ?? [];
+  const configOpts: string[] = [args.config ?? []].flat();
 
   /* eslint-disable-next-line no-restricted-syntax */
   const paths = findPaths(__dirname);

From 4ab6f559dd27717a9a05b1f412888b98e904c8fd Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Wed, 21 Oct 2020 21:04:57 +0200
Subject: [PATCH 4/8] app-config: merged dev config back into main config

---
 app-config.development.yaml                         | 13 -------------
 app-config.yaml                                     |  8 ++++++--
 .../default-app/app-config.development.yaml         | 13 -------------
 .../templates/default-app/app-config.yaml.hbs       |  8 ++++++--
 4 files changed, 12 insertions(+), 30 deletions(-)
 delete mode 100644 app-config.development.yaml
 delete mode 100644 packages/create-app/templates/default-app/app-config.development.yaml

diff --git a/app-config.development.yaml b/app-config.development.yaml
deleted file mode 100644
index 817847c6d6..0000000000
--- a/app-config.development.yaml
+++ /dev/null
@@ -1,13 +0,0 @@
-app:
-  baseUrl: http://localhost:3000
-
-backend:
-  baseUrl: http://localhost:7000
-  listen:
-    port: 7000
-  cors:
-    origin: http://localhost:3000
-    methods: [GET, POST, PUT, DELETE]
-    credentials: true
-  csp:
-    connect-src: ["'self'", 'http:', 'https:']
diff --git a/app-config.yaml b/app-config.yaml
index 6e49e765cd..05bf39b5b3 100644
--- a/app-config.yaml
+++ b/app-config.yaml
@@ -1,6 +1,6 @@
 app:
   title: Backstage Example App
-  baseUrl: http://localhost:7000
+  baseUrl: http://localhost:3000
   googleAnalyticsTrackingId: # UA-000000-0
 
 backend:
@@ -10,8 +10,12 @@ backend:
   database:
     client: sqlite3
     connection: ':memory:'
+  cors:
+    origin: http://localhost:3000
+    methods: [GET, POST, PUT, DELETE]
+    credentials: true
   csp:
-    connect-src: ["'self'", 'https:']
+    connect-src: ["'self'", 'http:', 'https:']
 
 # See README.md in the proxy-backend plugin for information on the configuration format
 proxy:
diff --git a/packages/create-app/templates/default-app/app-config.development.yaml b/packages/create-app/templates/default-app/app-config.development.yaml
deleted file mode 100644
index 817847c6d6..0000000000
--- a/packages/create-app/templates/default-app/app-config.development.yaml
+++ /dev/null
@@ -1,13 +0,0 @@
-app:
-  baseUrl: http://localhost:3000
-
-backend:
-  baseUrl: http://localhost:7000
-  listen:
-    port: 7000
-  cors:
-    origin: http://localhost:3000
-    methods: [GET, POST, PUT, DELETE]
-    credentials: true
-  csp:
-    connect-src: ["'self'", 'http:', 'https:']
diff --git a/packages/create-app/templates/default-app/app-config.yaml.hbs b/packages/create-app/templates/default-app/app-config.yaml.hbs
index b92cdf22bd..a0b9f156ed 100644
--- a/packages/create-app/templates/default-app/app-config.yaml.hbs
+++ b/packages/create-app/templates/default-app/app-config.yaml.hbs
@@ -1,6 +1,6 @@
 app:
   title: Scaffolded Backstage App
-  baseUrl: http://localhost:7000
+  baseUrl: http://localhost:3000
 
 organization:
   name: My Company
@@ -10,7 +10,11 @@ backend:
   listen:
     port: 7000
   csp:
-    connect-src: ["'self'", 'https:']
+    connect-src: ["'self'", 'http:', 'https:']
+  cors:
+    origin: http://localhost:3000
+    methods: [GET, POST, PUT, DELETE]
+    credentials: true
   {{#if dbTypeSqlite}}
   database:
     client: sqlite3

From 87a6e78d0350b2b49b7e6882b1fb5233856e1ad3 Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Wed, 21 Oct 2020 22:02:51 +0200
Subject: [PATCH 5/8] CHANGELOG: bump to alpha.25 and add entry for new
 --config flags

---
 CHANGELOG.md | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0bcce2966f..f445c189f4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,16 @@ If you encounter issues while upgrading to a newer version, don't hesitate to re
 
 ## Next Release
 
+### @backstage/cli
+
+- Configuration files are no longer selected through `APP_ENV` or `NODE_ENV`. The default configuration files are `app-config.yaml` and, fix it exists, `app-config.local.yaml` in the repo root. To load a different set of files, use `--config <path>` arguments.
+
+### @backstage/backend-common
+
+- Configuration files are no longer selected through `APP_ENV` or `NODE_ENV`. The default configuration files are `app-config.yaml` and, fix it exists, `app-config.local.yaml` in the repo root. To load a different set of files, use `--config <path>` arguments.
+
+## v0.1.1-alpha.25
+
 > Collect changes for the next release below
 
 ### @backstage/cli

From c2ea3cd26aa826b034bf91ffdac31206b4f93cb1 Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Thu, 22 Oct 2020 10:08:37 +0200
Subject: [PATCH 6/8] docs: updated to reflect new --config flags

---
 docs/conf/index.md                            | 10 +++---
 docs/conf/writing.md                          | 36 +++++++++++--------
 docs/support/project-structure.md             |  3 --
 .../examples/dice-roller/README.md            |  4 +--
 4 files changed, 29 insertions(+), 24 deletions(-)

diff --git a/docs/conf/index.md b/docs/conf/index.md
index e1dfc30582..2c3ee06ba6 100644
--- a/docs/conf/index.md
+++ b/docs/conf/index.md
@@ -15,11 +15,11 @@ allowing for customization.
 
 ## Supplying Configuration
 
-Configuration is stored in `app-config.yaml` files, with support for suffixes
-such as `app-config.production.yaml` to override values for specific
-environments. The configuration files themselves contain plain YAML, but with
-support for loading in secrets from various sources using for example `$env` and
-`$file` keys.
+Configuration is stored in YAML files where the defaults are `app-config.yaml`
+and `app-config.local.yaml` for local overrides. Other sets of files can by
+loaded by passing `--config <path>` flags. The configuration files themselves
+contain plain YAML, but with support for loading in secrets from various sources
+using for example `$env` and `$file` keys.
 
 It is also possible to supply configuration through environment variables, for
 example `APP_CONFIG_app_baseUrl=https://staging.example.com`. However these
diff --git a/docs/conf/writing.md b/docs/conf/writing.md
index bb4d0beb75..06d4b52f3f 100644
--- a/docs/conf/writing.md
+++ b/docs/conf/writing.md
@@ -55,20 +55,28 @@ picked up by the serve tasks of `@backstage/cli` for local development, and are
 injected by the entrypoint of the nginx container serving the frontend in a
 production build.
 
-## File Resolution
+## Configuration Files
 
 It is possible to have multiple configuration files, both to support different
 environments, but also to define configuration that is local to specific
-packages.
+packages. The configuration files to load are selected using a `--config <path>`
+flag, and it is possible to load any number of files. Paths are relative to the
+working directory of the executed process, for example `package/backend`. This
+means that to select a config file in the repo root when running the backend,
+you would use `--config ../../my-config.yaml`.
 
-All `app-config.yaml` files inside the monorepo root and package root are
-considered, as are files with additional `local` and environment affixes such as
-`development`, for example `app-config.local.yaml`,
-`app-config.production.yaml`, and `app-config.development.local.yaml`. Which
-environment config files are loaded is determined by the `APP_ENV` environment
-variable, or `NODE_ENV` if it is not set. Local configuration files are always
-loaded, but are meant for local development overrides and should typically be
-`.gitignore`'d.
+If no `config` flags are specified, the default behavior is to load
+`app-config.yaml` and, if it exists, `app-config.local.yaml` from the repo root.
+In the provided project setup, `app-config.local.yaml` is `.gitignore`'d, making
+it a good place to add config overrides and secrets for local development.
+
+Note that if any config flags are provided, the default `app-config.yaml` files
+are NOT loaded. To include them you need to explicitly include them with a flag,
+for example:
+
+```
+yarn start --config ../../app-config.yaml --config ../../app-config.staging.yaml
+```
 
 All loaded configuration files are merged together using the following rules:
 
@@ -84,10 +92,10 @@ order:
 
 - Configuration from the `APP_CONFIG_` environment variables has the highest
   priority, followed by files.
-- Files inside package directories have higher priority than those in the root
-  directory.
-- Files with environment affixes have higher priority than ones without.
-- Files with the `local` affix have higher priority than ones without.
+- Files loaded with config flags are ordered by priority, where the last flag
+  has the highest priority.
+- If no config flags are provided, `app-config.local.yaml` has higher priority
+  than `app-config.yaml`.
 
 ## Secrets
 
diff --git a/docs/support/project-structure.md b/docs/support/project-structure.md
index 277ca3929f..987d6a8ff3 100644
--- a/docs/support/project-structure.md
+++ b/docs/support/project-structure.md
@@ -228,9 +228,6 @@ future.
 - [`app-config.yaml`](https://github.com/spotify/backstage/tree/master/app-config.yaml) -
   Configuration for the app, both frontend and backend
 
-- [`app-config.development.yaml`](https://github.com/spotify/backstage/tree/master/app-config.development.yaml) -
-  Used for overriding configuration when developing locally.
-
 - [`catalog-info.yaml`](https://github.com/spotify/backstage/tree/master/catalog-info.yaml) -
   Description of Backstage in the Backstage Entity format.
 
diff --git a/plugins/kubernetes-backend/examples/dice-roller/README.md b/plugins/kubernetes-backend/examples/dice-roller/README.md
index 774867de04..bf3e7d261a 100644
--- a/plugins/kubernetes-backend/examples/dice-roller/README.md
+++ b/plugins/kubernetes-backend/examples/dice-roller/README.md
@@ -23,7 +23,7 @@ This can be used to run the kubernetes plugin locally against a mock service.
 6. Register existing component in Backstage
    - https://github.com/mclarke47/dice-roller/blob/master/catalog-info.yaml
 
-Update `app-config.development.yaml` as follows.
+Add or update `app-config.local.yaml` with the following:
 
 ```yaml
 kubernetes:
@@ -45,4 +45,4 @@ Mac copy to clipboard:
 kubectl get secret $(kubectl get sa dice-roller -o=json | jq -r .secrets[0].name) -o=json | jq -r '.data["token"]' | base64 --decode | pbcopy
 ```
 
-Paste into `app-config.development.yaml` `kubernetes.clusters[0].serviceAccountToken`
+Paste into `app-config.local.yaml` `kubernetes.clusters[0].serviceAccountToken`

From 3dec8022d23409877f5f0f51402562949237908e Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Thu, 22 Oct 2020 10:50:41 +0200
Subject: [PATCH 7/8] contrib/kubernetes: update plain example to load config
 with args

---
 .../plain_single_backend_deplyoment/deployment.yaml | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/contrib/kubernetes/plain_single_backend_deplyoment/deployment.yaml b/contrib/kubernetes/plain_single_backend_deplyoment/deployment.yaml
index 87dee94895..a20c47229d 100644
--- a/contrib/kubernetes/plain_single_backend_deplyoment/deployment.yaml
+++ b/contrib/kubernetes/plain_single_backend_deplyoment/deployment.yaml
@@ -28,6 +28,9 @@ spec:
           image: example-backend:latest
           imagePullPolicy: Never
 
+          command: [node, packages/backend]
+          args: [--config, app-config.yaml, --config, k8s-config.yaml]
+
           env:
             # We set this to development to make the backend start with incomplete configuration. In a production
             # deployment you will want to make sure that you have a full configuration, and remove any plugins that
@@ -35,10 +38,6 @@ spec:
             - name: NODE_ENV
               value: development
 
-              # This makes us load in `app-config.production.yaml` if there is one.
-            - name: APP_ENV
-              value: production
-
               # This makes it possible for the app to reach the backend when serving through `kubectl proxy`
               # If you expose the service using for example an ingress controller, you should
               # switch this out or remove it.
@@ -54,8 +53,8 @@ spec:
 
           volumeMounts:
             - name: config-volume
-              mountPath: /usr/src/app/app-config.local.yaml
-              subPath: app-config.local.yaml
+              mountPath: /usr/src/app/k8s-config.yaml
+              subPath: k8s-config.yaml
 
           resources:
             limits:
@@ -77,7 +76,7 @@ spec:
             name: backstage-config
             items:
               - key: app-config
-                path: app-config.local.yaml
+                path: k8s-config.yaml
 ---
 apiVersion: v1
 kind: ConfigMap

From f495ba9c18f4295b1d43adc44d2c097587e0c480 Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Thu, 22 Oct 2020 12:49:02 +0200
Subject: [PATCH 8/8] techdocs-backend: fix config loading in git-auth

---
 plugins/techdocs-backend/src/git-auth.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/plugins/techdocs-backend/src/git-auth.ts b/plugins/techdocs-backend/src/git-auth.ts
index d77596929f..b580a6f05b 100644
--- a/plugins/techdocs-backend/src/git-auth.ts
+++ b/plugins/techdocs-backend/src/git-auth.ts
@@ -93,7 +93,11 @@ export function getAzureHostToken(
 export const getTokenForGitRepo = async (
   repositoryUrl: string,
 ): Promise<string | undefined> => {
-  const config = await loadBackendConfig({ logger: getRootLogger() });
+  // TODO(Rugvip): Config should not be loaded here, pass it in instead
+  const config = await loadBackendConfig({
+    logger: getRootLogger(),
+    argv: process.argv,
+  });
 
   const host = getGitHost(repositoryUrl);
   const type = getGitRepoType(repositoryUrl);