feat: add option to trim a prefix from env variables (#6)

src/kubernetes-helpers.ts

@@ -24,6 +24,7 @@ import {
 } from 'yargs';
 
 import { commands } from './commands';
+import { envTrimPrefix } from './utils/env-trim-prefix';
 import { KubernetesApi } from './utils/kubernetes-api';
 import { Logger, LogLevel } from './utils/logger';
 
@@ -41,6 +42,12 @@ middleware((args: Arguments<any>) => {
   Logger.level = args['logLevel'];
 });
 
+middleware((args: Arguments<any>) => {
+  if (args.trimEnvPrefix) {
+    envTrimPrefix(args.trimEnvPrefix);
+  }
+});
+
 middleware((args: Arguments<any>) => {
   if (args.namespace) {
     KubernetesApi.namespaceOverride = args.namespace;
@@ -80,6 +87,11 @@ option('log-level', {
   choices: ['debug', 'info', 'warn', 'error'],
   default: 'info',
 });
+option('trim-env-prefix', {
+  alias: 'p',
+  description: 'Prefix to trim from env variables',
+  default: '',
+});
 
 try {
   const configPath = findUp.sync(['.kubyrc', '.kubyrc.json']);

src/root-arguments.ts

@@ -5,5 +5,6 @@ export interface RootArguments {
   logLevel: LogLevel;
   context?: string;
   namespace?: string;
+  trimEnvPrefix?: string;
   getYargsCompletions?: boolean;
 }

src/utils/env-trim-prefix.ts

@@ -0,0 +1,6 @@
+export function envTrimPrefix(prefix: string): void {
+    Object.keys(process.env)
+        .filter(n => n.startsWith(prefix))
+        .map(n => n.substr(prefix.length))
+        .forEach(n => process.env[n] = process.env[prefix + n]);
+}

test/utils/env-trim-prefix.spec.ts

@@ -0,0 +1,43 @@
+import { envTrimPrefix } from '../../src/utils/env-trim-prefix';
+
+describe('util / envTrimPrefix', () => {
+  describe('envTrimPrefix()', () => {
+    beforeAll(() => {
+      process.env['STA_FOO'] = 'hello foo';
+      process.env['BAR'] = 'hello bar';
+    });
+
+    afterAll(() => {
+      delete process.env.STA_FOO;
+      delete process.env.FOO;
+      delete process.env.BAR;
+    });
+
+    it('should trim prefix from env vars', () => {
+      envTrimPrefix('STA_');
+
+      expect(process.env.STA_FOO).toBe('hello foo');
+      expect(process.env.FOO).toBe('hello foo');
+      expect(process.env.BAR).toBe('hello bar');
+    });
+
+    it('should trim prefix from env vars and override existing vars', () => {
+      process.env.FOO = 'hello existing foo';
+
+      envTrimPrefix('STA_');
+
+      expect(process.env.STA_FOO).toBe('hello foo');
+      expect(process.env.FOO).toBe('hello foo');
+      expect(process.env.BAR).toBe('hello bar');
+    });
+
+    it('should should not touch env vars with a nonsense prefix', () => {
+      envTrimPrefix('STAXX_');
+
+      expect(process.env.STA_FOO).toBe('hello foo');
+      expect(process.env.FOO).toBe('hello foo');
+      expect(process.env.BAR).toBe('hello bar');
+    });
+
+  });
+});