build(docs-infra): upgrade preview server docker image to Debian 9 (#29976)

Previously, the preview server docker image was based on Debian 8
(jessie). Recently, `jessie-updates` and `jessie-backborts` were removed
from the Debian mirrors ([more info][1]), thus breaking new builds of
the image.

Instead of updating `/etc/apt/sources.list` to remove the obsolete
sources, this commit upgrades to Debian 9 (stretch).

(The GCE VM running the preview server docker container was also
upgraded from Debian 8 to 9 this morning.)

---
Other changes:
- Removed dependency on `chkconfig`, which is not supported on Debian 9.
- Installing `nginx` from the regular repositories (instead of
  `*-backports).
- Upgraded to `pm2` v3, which can handle hooking itself up to system
  startup better (without `chkconfig` - see above).
- Updated tests to reflect the fact that `nginx` has dropped the reason
  phrase in response status lines for HTTP/2 (in compliance with
  [the spec][2]). (HTTP/1.1: `HTTP/1.1 200 OK` | HTTP/2: `HTTP/2 200`)

[1]: https://www.lucas-nussbaum.net/blog/?p=947
[2]: https://http2.github.io/http2-spec/#rfc.section.8.1.2.4

PR Close #29976

aio/aio-builds-setup/dockerbuild/Dockerfile

@@ -1,5 +1,5 @@
 # Image metadata and config
-FROM debian:jessie
+FROM debian:stretch
 
 LABEL name="angular.io PR preview" \
       description="This image implements the PR preview functionality for angular.io." \
@@ -76,21 +76,20 @@ RUN apt-get update -y && apt-get install -y curl
 RUN curl --silent --show-error --location https://deb.nodesource.com/setup_10.x | bash -
 RUN curl --silent --show-error https://dl.yarnpkg.com/debian/pubkey.gpg | apt-key add -
 RUN echo "deb https://dl.yarnpkg.com/debian/ stable main" | tee /etc/apt/sources.list.d/yarn.list
-RUN echo "deb http://ftp.debian.org/debian jessie-backports main" | tee /etc/apt/sources.list.d/backports.list
+RUN echo "deb http://ftp.debian.org/debian stretch-backports main" | tee /etc/apt/sources.list.d/backports.list
 
 
 # Install packages
 RUN apt-get update -y && apt-get install -y \
-    chkconfig \
     cron \
     dnsmasq \
     nano \
+    nginx \
     nodejs \
     openssl \
     rsyslog \
     yarn
-RUN apt-get install -t jessie-backports -y nginx
-RUN yarn global add pm2@2
+RUN yarn global add pm2@3
 
 
 # Set up log rotation
@@ -151,8 +150,7 @@ RUN sed -i "s|{{\$AIO_PREVIEW_SERVER_PORT}}|$TEST_AIO_PREVIEW_SERVER_PORT|g" /et
 
 
 # Set up pm2
-RUN pm2 startup systemv -u root > /dev/null
-RUN chkconfig pm2-root on
+RUN pm2 startup --user root > /dev/null
 
 
 # Set up the shell scripts

aio/aio-builds-setup/dockerbuild/scripts-js/lib/verify-setup/helper.ts

@@ -1,7 +1,6 @@
 // Imports
 import * as cp from 'child_process';
 import * as fs from 'fs';
-import * as http from 'http';
 import * as path from 'path';
 import * as shell from 'shelljs';
 import {AIO_DOWNLOADS_DIR, HIDDEN_DIR_PREFIX} from '../common/constants';
@@ -105,18 +104,7 @@ class Helper {
     Object.keys(this.portPerScheme).forEach(scheme => suiteFactory(scheme, this.portPerScheme[scheme]));
   }
 
-  public verifyResponse(status: number | [number, string], regex: string | RegExp = /^/): VerifyCmdResultFn {
-    let statusCode: number;
-    let statusText: string;
-
-    if (Array.isArray(status)) {
-      statusCode = status[0];
-      statusText = status[1];
-    } else {
-      statusCode = status;
-      statusText = http.STATUS_CODES[statusCode] || 'UNKNOWN_STATUS_CODE';
-    }
-
+  public verifyResponse(status: number, regex: string | RegExp = /^/): VerifyCmdResultFn {
     return (result: CmdResult) => {
       const [headers, body] = result.stdout.
         split(/(?:\r?\n){2,}/).
@@ -131,7 +119,7 @@ class Helper {
       }
 
       expect(result.success).toBe(true);
-      expect(headers).toContain(`${statusCode} ${statusText}`);
+      expect(headers).toMatch(new RegExp(`HTTP/(?:1\\.1|2) ${status} `));
       expect(body).toMatch(regex);
     };
   }

aio/aio-builds-setup/dockerbuild/scripts-js/lib/verify-setup/nginx.e2e.ts

@@ -259,10 +259,10 @@ describe(`nginx`, () => {
 
       it('should disallow non-GET requests', async () => {
         await Promise.all([
-          h.runCmd(`curl -iLX POST ${baseUrl}/42`).then(h.verifyResponse([405, 'Not Allowed'])),
-          h.runCmd(`curl -iLX PUT ${baseUrl}/42`).then(h.verifyResponse([405, 'Not Allowed'])),
-          h.runCmd(`curl -iLX PATCH ${baseUrl}/42`).then(h.verifyResponse([405, 'Not Allowed'])),
-          h.runCmd(`curl -iLX DELETE ${baseUrl}/42`).then(h.verifyResponse([405, 'Not Allowed'])),
+          h.runCmd(`curl -iLX POST ${baseUrl}/42`).then(h.verifyResponse(405)),
+          h.runCmd(`curl -iLX PUT ${baseUrl}/42`).then(h.verifyResponse(405)),
+          h.runCmd(`curl -iLX PATCH ${baseUrl}/42`).then(h.verifyResponse(405)),
+          h.runCmd(`curl -iLX DELETE ${baseUrl}/42`).then(h.verifyResponse(405)),
         ]);
       });
 
@@ -295,10 +295,10 @@ describe(`nginx`, () => {
         const url = `${scheme}://${host}/circle-build`;
 
         Promise.all([
-          h.runCmd(`curl -iLX GET ${url}`).then(h.verifyResponse([405, 'Not Allowed'])),
-          h.runCmd(`curl -iLX PUT ${url}`).then(h.verifyResponse([405, 'Not Allowed'])),
-          h.runCmd(`curl -iLX PATCH ${url}`).then(h.verifyResponse([405, 'Not Allowed'])),
-          h.runCmd(`curl -iLX DELETE ${url}`).then(h.verifyResponse([405, 'Not Allowed'])),
+          h.runCmd(`curl -iLX GET ${url}`).then(h.verifyResponse(405)),
+          h.runCmd(`curl -iLX PUT ${url}`).then(h.verifyResponse(405)),
+          h.runCmd(`curl -iLX PATCH ${url}`).then(h.verifyResponse(405)),
+          h.runCmd(`curl -iLX DELETE ${url}`).then(h.verifyResponse(405)),
         ]).then(done);
       });
 
@@ -334,10 +334,10 @@ describe(`nginx`, () => {
 
       it('should disallow non-POST requests', done => {
         Promise.all([
-          h.runCmd(`curl -iLX GET ${url}`).then(h.verifyResponse([405, 'Not Allowed'])),
-          h.runCmd(`curl -iLX PUT ${url}`).then(h.verifyResponse([405, 'Not Allowed'])),
-          h.runCmd(`curl -iLX PATCH ${url}`).then(h.verifyResponse([405, 'Not Allowed'])),
-          h.runCmd(`curl -iLX DELETE ${url}`).then(h.verifyResponse([405, 'Not Allowed'])),
+          h.runCmd(`curl -iLX GET ${url}`).then(h.verifyResponse(405)),
+          h.runCmd(`curl -iLX PUT ${url}`).then(h.verifyResponse(405)),
+          h.runCmd(`curl -iLX PATCH ${url}`).then(h.verifyResponse(405)),
+          h.runCmd(`curl -iLX DELETE ${url}`).then(h.verifyResponse(405)),
         ]).then(done);
       });