Add stop command to unmock-server. (#374)

* Add stop command by writing server PID to file.

* Fix prettier.

* Add simple test.

* Fix prettier.

* Fix deletion in test.

* Delete server PID file when process exits.

* Clean-up.

packages/unmock-server/package.json

@@ -31,6 +31,7 @@
     "express": "^4.17.1",
     "helmet": "^3.21.1",
     "http-proxy": "^1.18.0",
+    "mkdirp": "^0.5.1",
     "node-forge": "^0.9.1",
     "unmock-core": "file:../unmock-core",
     "unmock-node": "file:../unmock-node"

packages/unmock-server/src/__tests__/pid.test.ts

@@ -0,0 +1,15 @@
+import * as path from "path";
+import { deletePidFile, readPidIfExists, writePid } from "../pid";
+
+const LOCAL_CONFIG_DIRECTORY = path.resolve(__dirname, ".unmock");
+
+afterEach(() => {
+  deletePidFile(LOCAL_CONFIG_DIRECTORY);
+});
+
+it("should write process PID to given file and read it", () => {
+  const pid = process.pid;
+  writePid(LOCAL_CONFIG_DIRECTORY);
+  const writtenPid = readPidIfExists(LOCAL_CONFIG_DIRECTORY);
+  expect(writtenPid).toBe(pid);
+});

packages/unmock-server/src/commands/start.ts

@@ -1,7 +1,25 @@
 import { Command, flags } from "@oclif/command";
+import debug from "debug";
+import { deletePidFile, writePid } from "../pid";
 import { startProxy } from "../proxy";
 import { buildApp, startServer } from "../server";
 
+const debugLog = debug("unmock-server:start");
+
+const log = (...args: any[]) => console.log(...args); // tslint:disable-line
+
+const addCleanUp = (callback: () => void) => {
+  process.on("exit", callback);
+
+  process.on("uncaughtException", e => {
+    log("Uncaught exception: %s", e.stack);
+    process.exit(99);
+  });
+
+  process.on("SIGINT", () => process.exit(2));
+  process.on("SIGTERM", () => process.exit(2));
+};
+
 export default class Start extends Command {
   public static description = "Start unmock server and proxy";
 
@@ -17,10 +35,25 @@ export default class Start extends Command {
   public static args = [];
 
   public async run() {
+    debugLog("Starting.");
     const run = () => {
       const { app } = buildApp();
-      startServer(app);
-      startProxy();
+      const [httpServer, httpsServer] = startServer(app);
+      const proxyServer = startProxy();
+
+      debugLog("Writing PID to file for closing...");
+      writePid();
+
+      const cleanUp = () => {
+        debugLog("Received SIGTERM. Stopping servers.");
+        httpServer.close();
+        httpsServer.close();
+        proxyServer.close();
+        debugLog("Servers closed.");
+        deletePidFile();
+      };
+
+      addCleanUp(cleanUp);
     };
     run();
   }

packages/unmock-server/src/commands/stop.ts

@@ -0,0 +1,44 @@
+import { Command, flags } from "@oclif/command";
+import debug from "debug";
+import { readPidIfExists, TERM_SIGNAL } from "../pid";
+
+const debugLog = debug("unmock-server:stop");
+const log = (...args: any[]) => console.log(...args); // tslint:disable-line
+
+export default class Stop extends Command {
+  public static description = "Stop unmock server and proxy.";
+
+  public static examples = [
+    `$ unmock-server stop
+`,
+  ];
+
+  public static flags = {
+    help: flags.help({ char: "h" }),
+  };
+
+  public static args = [];
+
+  /**
+   * Server process is stopped by sending a SIGTERM to the process PID written to the file-system.
+   */
+  public async run() {
+    const pidOrNull = readPidIfExists();
+
+    if (pidOrNull === null) {
+      log("Server not running.");
+      return;
+    }
+
+    try {
+      process.kill(pidOrNull, 0);
+    } catch (ex) {
+      log("Server not running.");
+      return;
+    }
+
+    debugLog("Sending %s to PID %d", TERM_SIGNAL, pidOrNull);
+    process.kill(pidOrNull, TERM_SIGNAL);
+    log("Server stopped.");
+  }
+}

packages/unmock-server/src/pid.ts

@@ -0,0 +1,64 @@
+/* Code for saving process PID into local file system.*/
+import debug from "debug";
+import * as fs from "fs";
+import * as mkdirp from "mkdirp";
+import * as os from "os";
+import * as path from "path";
+
+const debugLog = debug("unmock-server:pid");
+
+export const DEFAULT_CONFIG_DIRECTORY = path.resolve(os.homedir(), ".unmock");
+
+// Signal used for terminating process
+export const TERM_SIGNAL = "SIGTERM";
+
+export const PID_FILENAME = "server.pid";
+
+const ensureDirExists = (directory: string) => {
+  if (!fs.existsSync(directory)) {
+    debugLog(`Creating directory: ${directory}`);
+    return mkdirp.sync(directory);
+  }
+
+  if (!fs.lstatSync(directory).isDirectory()) {
+    throw Error(`Destination exists but is not directory: ${directory}`);
+  }
+
+  debugLog(`Directory exists: ${directory}`);
+
+  return;
+};
+
+export const writePid = (directory = DEFAULT_CONFIG_DIRECTORY) => {
+  const pid = process.pid;
+
+  ensureDirExists(directory);
+
+  const pidFile = path.join(directory, PID_FILENAME);
+  debugLog("Writing pid (%d) to %s", pid, pidFile);
+  fs.writeFileSync(pidFile, pid);
+};
+
+export const readPidIfExists = (
+  directory = DEFAULT_CONFIG_DIRECTORY,
+): number | null => {
+  const pidFile = path.join(directory, PID_FILENAME);
+  if (!fs.existsSync(pidFile)) {
+    debugLog("File not found: %s", pidFile);
+    return null;
+  }
+
+  const contents = fs.readFileSync(pidFile).toString();
+
+  return parseInt(contents, 10);
+};
+
+export const deletePidFile = (directory = DEFAULT_CONFIG_DIRECTORY): void => {
+  const pidFile = path.join(directory, PID_FILENAME);
+  if (!fs.existsSync(pidFile)) {
+    debugLog("File not found: %s", pidFile);
+    return;
+  }
+  debugLog("Deleting file %s.", pidFile);
+  fs.unlinkSync(pidFile);
+};

packages/unmock-server/src/server.ts

@@ -147,4 +147,6 @@ export const startServer = (app: express.Express) => {
   httpsServer.listen(httpsPort, () => {
     log("HTTPS server starting on port: " + httpsPort);
   });
+
+  return [httpServer, httpsServer];
 };