help-documentation-tool: Add tools for checking user help documentation.

- Add spider for documentation crawler, which processes user help
  documentation on test development server.
- Add tool script for help documentation checking launching.

Fixes #2639

tools/documentation_crawler/documentation_crawler/spiders/check_help_documentation.py

@@ -0,0 +1,15 @@
+#!/usr/bin/env python
+from __future__ import print_function
+
+from .common.spiders import BaseDocumentationSpider
+
+
+class HelpDocumentationSpider(BaseDocumentationSpider):
+    name = "help_documentation_crawler"
+    start_urls = ['http://localhost:9981/help']
+    deny_domains = [] # type: List[str]
+
+    def _is_external_url(self, url):
+        # type: (str) -> bool
+        is_external = url.startswith('http') and 'localhost:9981/help' not in url
+        return is_external or self._has_extension(url)

tools/test-help-documentation.py

@@ -0,0 +1,73 @@
+#!/usr/bin/env python
+from __future__ import print_function
+import os
+import sys
+import subprocess
+
+import time
+
+try:
+    # We don't actually need typing, but it's a good guard for being
+    # outside a Zulip virtualenv.
+    from typing import Iterable
+    import requests
+except ImportError as e:
+    print("ImportError: {}".format(e))
+    print("You need to run the Zulip tests inside a Zulip dev environment.")
+    print("If you are using Vagrant, you can `vagrant ssh` to enter the Vagrant guest.")
+    sys.exit(1)
+
+os.environ["EXTERNAL_HOST"] = "localhost:9981"
+
+
+def assert_server_running(server):
+    # type: (subprocess.Popen) -> None
+    """Get the exit code of the server, or None if it is still running."""
+    if server.poll() is not None:
+        raise RuntimeError('Server died unexpectedly! Check %s' % (LOG_FILE,))
+
+
+def server_is_up(server):
+    # type: (subprocess.Popen) -> bool
+    assert_server_running(server)
+    try:
+        # We could get a 501 error if the reverse proxy is up but the Django app isn't.
+        return requests.get('http://127.0.0.1:9981/accounts/home').status_code == 200
+    except:
+        return False
+
+
+subprocess.check_call(['mkdir', '-p', 'var/help-documentation'])
+
+LOG_FILE = 'var/help-documentation/server.log'
+if os.path.exists(LOG_FILE) and os.path.getsize(LOG_FILE) < 100000:
+    log = open(LOG_FILE, 'a')
+    log.write('\n\n')
+else:
+    log = open(LOG_FILE, 'w')
+server = subprocess.Popen(('tools/run-dev.py', '--test'), stdout=log, stderr=log)
+sys.stdout.write('Waiting for test server')
+try:
+    while not server_is_up(server):
+        sys.stdout.write('.')
+        sys.stdout.flush()
+        time.sleep(0.1)
+    sys.stdout.write('\n')
+
+    ret = subprocess.call(('scrapy', 'crawl_with_status', 'help_documentation_crawler'),
+                          cwd='tools/documentation_crawler')
+finally:
+    assert_server_running(server)
+    server.terminate()
+
+if ret != 0:
+    print("\033[0;91m")
+    print("Failed")
+    print("\033[0m")
+else:
+    print("\033[0;92m")
+    print("Passed!")
+    print("\033[0m")
+
+
+sys.exit(ret)