migrate to polling watcher (remove chokidar) (#2202)

packages/kube-config/__tests__/client-config.test.js

@@ -23,7 +23,7 @@ describe('client-config', () => {
   const initClientConfig = signal => {
     const config = new Config(kubeconfig)
     const reactive = !!signal
-    clientConfig = new ClientConfig(config, { reactive, signal })
+    clientConfig = new ClientConfig(config, { reactive, interval: 500, signal })
     return reactive
       ? onceEvent(clientConfig.watcher, 'ready')
       : Promise.resolve()

packages/kube-config/__tests__/kube-config.test.js

@@ -10,8 +10,6 @@ const fs = require('fs')
 const path = require('path')
 const os = require('os')
 const yaml = require('js-yaml')
-const EventEmitter = require('events')
-const chokidar = require('chokidar')
 const { mockGetToken } = require('gtoken')
 const { cloneDeep } = require('lodash')
 const Config = require('../lib/Config')
@@ -33,17 +31,10 @@ describe('kube-config', () => {
   const accessToken = 'access-token'
 
   beforeEach(() => {
-    jest.spyOn(chokidar, 'watch').mockImplementationOnce(() => {
-      const emitter = new EventEmitter()
-      emitter.close = jest.fn().mockImplementation(() => Promise.resolve())
-      process.nextTick(() => emitter.emit('ready'))
-      return emitter
-    })
     jest.spyOn(fs, 'readFileSync')
   })
 
   afterEach(() => {
-    chokidar.watch.mockRestore()
     fs.readFileSync.mockRestore()
   })
 

packages/kube-config/__tests__/polling-watcher.test.js

@@ -0,0 +1,103 @@
+//
+// SPDX-FileCopyrightText: 2023 SAP SE or an SAP affiliate company and Gardener contributors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+'use strict'
+
+const fs = require('fs/promises')
+const { globalLogger: logger } = require('@gardener-dashboard/logger')
+const PollingWatcher = require('../lib/PollingWatcher')
+
+const actualNextTick = jest.requireActual('process').nextTick
+const flushPromises = () => new Promise(actualNextTick)
+
+describe('polling-watcher', () => {
+  beforeAll(() => {
+    jest.useFakeTimers()
+  })
+
+  afterAll(() => {
+    jest.useRealTimers()
+  })
+
+  describe('#run', () => {
+    const filename = '/path/to/file'
+    const content = 'content'
+    const interval = 10
+    let ac
+    let fn
+
+    const createWatcher = (signal = ac.signal) => {
+      return new PollingWatcher([filename], {
+        interval,
+        signal,
+      })
+    }
+
+    const advanceTimersByOneInterval = async () => {
+      jest.advanceTimersByTime(interval + 1)
+      await flushPromises()
+    }
+
+    beforeEach(() => {
+      ac = new AbortController()
+      fn = jest.fn()
+      jest.spyOn(fs, 'readFile').mockResolvedValue(content)
+      logger.info.mockClear()
+      logger.error.mockClear()
+    })
+
+    afterEach(() => {
+      fs.readFile.mockRestore()
+      ac.abort()
+    })
+
+    it('should read the file content and call the callback function', async () => {
+      createWatcher().run(fn)
+      expect(fn).toHaveBeenCalledTimes(0)
+      await advanceTimersByOneInterval()
+      expect(fn).toHaveBeenCalledTimes(1)
+      expect(fn.mock.calls[0]).toEqual([filename, content])
+      expect(logger.info).toHaveBeenCalledTimes(1)
+      expect(logger.info.mock.calls[0]).toEqual(['[kube-config] updated content of file `%s`', filename])
+    })
+
+    it('should fail to read file content and not call the callback function', async () => {
+      const error = new Error('no such file')
+      fs.readFile.mockRejectedValueOnce(error)
+      createWatcher().run(fn)
+      expect(fn).toHaveBeenCalledTimes(0)
+      await advanceTimersByOneInterval()
+      expect(fn).toHaveBeenCalledTimes(0)
+      expect(logger.error).toHaveBeenCalledTimes(1)
+      expect(logger.error.mock.calls[0]).toEqual(['[kube-config] failed to stat file `%s`: %s', filename, error.message])
+    })
+
+    it('should do nothing if abortet before run', async () => {
+      const watcher = createWatcher()
+      ac.abort()
+      watcher.run(fn)
+      await advanceTimersByOneInterval()
+      expect(fn).toHaveBeenCalledTimes(0)
+    })
+
+    it('should do nothing if already abortet', async () => {
+      ac.abort()
+      const watcher = createWatcher()
+      watcher.run(fn)
+      await advanceTimersByOneInterval()
+      expect(fn).toHaveBeenCalledTimes(0)
+    })
+
+    it('should run a watcher without abort signal', async () => {
+      const watcher = createWatcher(null)
+      ac.abort()
+      watcher.run(fn)
+      await advanceTimersByOneInterval()
+      expect(fn).toHaveBeenCalledTimes(1)
+      watcher.abort()
+    })
+  })
+})

packages/kube-config/lib/ClientConfig.js

@@ -8,7 +8,7 @@
 
 const assert = require('assert').strict
 const fs = require('fs')
-const Watcher = require('./Watcher')
+const Watcher = require('./PollingWatcher')
 
 function getCluster ({ currentCluster }, files) {
   const cluster = {}
@@ -25,7 +25,8 @@ function getCluster ({ currentCluster }, files) {
       cluster.certificateAuthority = base64Decode(caData)
     } else if (caFile) {
       files.set(caFile, 'certificateAuthority')
-      cluster.certificateAuthority = fs.readFileSync(caFile, 'utf8') // eslint-disable-line security/detect-non-literal-fs-filename
+      // eslint-disable-next-line security/detect-non-literal-fs-filename -- caFile is not user input
+      cluster.certificateAuthority = fs.readFileSync(caFile, 'utf8')
     }
     if (typeof insecureSkipTlsVerify === 'boolean') {
       cluster.insecureSkipTlsVerify = insecureSkipTlsVerify
@@ -55,14 +56,17 @@ function getUser ({ currentUser }, files) {
       user.clientKey = base64Decode(keyData)
     } else if (certFile && keyFile) {
       files.set(certFile, 'clientCert')
-      user.clientCert = fs.readFileSync(certFile, 'utf8') // eslint-disable-line security/detect-non-literal-fs-filename
+      // eslint-disable-next-line security/detect-non-literal-fs-filename -- certFile is not user input
+      user.clientCert = fs.readFileSync(certFile, 'utf8')
       files.set(keyFile, 'clientKey')
-      user.clientKey = fs.readFileSync(keyFile, 'utf8') // eslint-disable-line security/detect-non-literal-fs-filename
+      // eslint-disable-next-line security/detect-non-literal-fs-filename -- keyFile is not user input
+      user.clientKey = fs.readFileSync(keyFile, 'utf8')
     } else if (token) {
       user.token = token
     } else if (tokenFile) {
       files.set(tokenFile, 'token')
-      user.token = fs.readFileSync(tokenFile, 'utf8') // eslint-disable-line security/detect-non-literal-fs-filename
+      // eslint-disable-next-line security/detect-non-literal-fs-filename -- tokenFile is not user input
+      user.token = fs.readFileSync(tokenFile, 'utf8')
     } else if (username && password) {
       user.username = username
       user.password = password

packages/kube-config/lib/PollingWatcher.js

@@ -0,0 +1,65 @@
+//
+// SPDX-FileCopyrightText: 2024 SAP SE or an SAP affiliate company and Gardener contributors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+'use strict'
+
+const fs = require('fs/promises')
+const EventEmitter = require('events')
+const { globalLogger: logger } = require('@gardener-dashboard/logger')
+
+class PollingWatcher extends EventEmitter {
+  #paths
+  #interval
+  #intervalId
+  #state = 'initial'
+
+  constructor (paths, options) {
+    super()
+    this.#paths = paths
+    this.#interval = options?.interval ?? 300_000
+    process.nextTick(() => {
+      this.#state = 'ready'
+      logger.debug('[kube-config] watcher ready')
+      this.emit('ready')
+    })
+    const signal = options?.signal
+    if (signal instanceof AbortSignal) {
+      if (!signal.aborted) {
+        signal.addEventListener('abort', () => this.abort(), { once: true })
+      } else {
+        this.#state = 'aborted'
+      }
+    }
+  }
+
+  run (fn) {
+    if (['initial', 'ready'].includes(this.#state)) {
+      const tryReadFile = async path => {
+        try {
+          // eslint-disable-next-line security/detect-non-literal-fs-filename -- path is not user input
+          const value = await fs.readFile(path, 'utf8')
+          logger.info('[kube-config] updated content of file `%s`', path)
+          fn(path, value)
+        } catch (err) {
+          logger.error('[kube-config] failed to stat file `%s`: %s', path, err.message)
+        }
+      }
+      this.#state = 'running'
+      this.#intervalId = setInterval(() => {
+        for (const path of this.#paths) {
+          tryReadFile(path)
+        }
+      }, this.#interval)
+    }
+  }
+
+  abort () {
+    this.#state = 'aborted'
+    clearInterval(this.#intervalId)
+  }
+}
+
+module.exports = PollingWatcher