feat(cli): wait for tls cert on create

This adds logic to wait up to 5 seconds for the tls cert file to be
created on the `create` command. Since this command may be called
immediately after xud is launched for the first time and the cert won't
be created until xud is done initializing, this will help avoid
unnecessary failures and repeated attempts.

Author: sangaman

lib/cli/command.ts

@@ -9,15 +9,15 @@ import { getDefaultCertPath } from './utils';
  * @param argv the command line arguments
  */
 export const loadXudClient = (argv: Arguments) => {
-  const certPath = argv.tlscertpath ? argv.tlscertpath : getDefaultCertPath();
+  const certPath = argv.tlscertpath || getDefaultCertPath();
   const cert = fs.readFileSync(certPath);
   const credentials = grpc.credentials.createSsl(cert);
 
   return new XudClient(`${argv.rpchost}:${argv.rpcport}`, credentials);
 };
 
 export const loadXudInitClient = (argv: Arguments) => {
-  const certPath = argv.tlscertpath ? argv.tlscertpath : getDefaultCertPath();
+  const certPath = argv.tlscertpath || getDefaultCertPath();
   const cert = fs.readFileSync(certPath);
   const credentials = grpc.credentials.createSsl(cert);
 

lib/cli/commands/create.ts

@@ -1,14 +1,47 @@
+import { accessSync, watch } from 'fs';
+import path from 'path';
 import readline from 'readline';
 import { Arguments } from 'yargs';
 import { CreateNodeRequest, CreateNodeResponse } from '../../proto/xudrpc_pb';
 import { callback, loadXudInitClient } from '../command';
+import { getDefaultCertPath } from '../utils';
 
 export const command = 'create';
 
 export const describe = 'use this to create a new xud instance and set a password';
 
 export const builder = {};
 
+const waitForCert = (certPath: string) => {
+  return new Promise<void>((resolve, reject) => {
+    try {
+      accessSync(certPath);
+      resolve();
+    } catch (err) {
+      if (err.code === 'ENOENT') {
+        // wait up to 5 seconds for the tls.cert file to be created in case
+        // this is the first time xud has been run
+        const certDir = path.dirname(certPath);
+        const certFilename = path.basename(certPath);
+        const fsWatcher = watch(certDir, (event, filename) => {
+          if (event === 'change' && filename === certFilename) {
+            clearTimeout(timeout);
+            fsWatcher.close();
+            resolve();
+          }
+        });
+        const timeout = setTimeout(() => {
+          fsWatcher.close();
+          reject(`timed out waiting for cert to be created at ${certPath}`);
+        }, 5000);
+      } else {
+        // we handle errors due to file not existing, otherwise reject
+        reject(err);
+      }
+    }
+  });
+};
+
 const formatOutput = (response: CreateNodeResponse.AsObject) => {
   if (response.seedMnemonicList.length === 24) {
     const WORDS_PER_ROW = 4;
@@ -49,19 +82,30 @@ export const handler = (argv: Arguments) => {
   process.stdout.write('Enter a password: ');
   rl.question('', (password1) => {
     process.stdout.write('\nRe-enter password: ');
-    rl.question('', (password2) => {
+    rl.question('', async (password2) => {
       process.stdout.write('\n\n');
       rl.close();
       if (password1 === password2) {
         const request = new CreateNodeRequest();
         request.setPassword(password1);
+
+        const certPath = argv.tlscertpath ? argv.tlscertpath : getDefaultCertPath();
+        try {
+          await waitForCert(certPath);
+        } catch (err) {
+          console.error(err);
+          process.exitCode = 1;
+          return;
+        }
+
         const client = loadXudInitClient(argv);
         // wait up to 3 seconds for rpc server to listen before call in case xud was just started
         client.waitForReady(Date.now() + 3000, () => {
           client.createNode(request, callback(argv, formatOutput));
         });
       } else {
-        console.log('Passwords do not match, please try again.');
+        process.exitCode = 1;
+        console.error('Passwords do not match, please try again');
       }
     });
   });