Alias zuul git repos to git.zuul-ci.org

This adds support for the cgit-alias directive added in
https://review.openstack.org/555105.  It's safe to land this change
before or after the implementation.

It also aliases the zuul project repos to git.zuul-ci.org.

Change-Id: I05a7156e092faad1457973b88537ec73012a5c96

gerrit/projects.yaml

@@ -249,6 +249,9 @@
     - openstack-ci
 - project: openstack-infra/nodepool
   use-storyboard: true
+  cgit-alias:
+    site: git.zuul-ci.org
+    path: nodepool
   groups:
     - openstack-ci
   description: Manage a pool of nodes for a distributed test infrastructure
@@ -837,16 +840,25 @@
   acl-config: /home/gerrit2/acls/openstack-infra/zuul.config
 - project: openstack-infra/zuul
   use-storyboard: true
+  cgit-alias:
+    site: git.zuul-ci.org
+    path: zuul
   groups:
     - openstack-ci
   description: The Gatekeeper, or a project gating system
 - project: openstack-infra/zuul-base-jobs
   use-storyboard: true
+  cgit-alias:
+    site: git.zuul-ci.org
+    path: zuul-base-jobs
   groups:
     - openstack-ci
   description: Zuul base job definition
 - project: openstack-infra/zuul-jobs
   use-storyboard: true
+  cgit-alias:
+    site: git.zuul-ci.org
+    path: zuul-jobs
   groups:
     - openstack-ci
   description: Ansible job definitions for Zuul
@@ -857,11 +869,17 @@
   description: Zuul packaging
 - project: openstack-infra/zuul-sphinx
   use-storyboard: true
+  cgit-alias:
+    site: git.zuul-ci.org
+    path: zuul-sphinx
   groups:
     - openstack-ci
   description: Sphinx extension for Zuul jobs
 - project: openstack-infra/zuul-website
   use-storyboard: true
+  cgit-alias:
+    site: git.zuul-ci.org
+    path: zuul-website
   groups:
     - openstack-ci
   description: The contents of the Zuul website

tools/check_valid_gerrit_projects.py

@@ -108,11 +108,13 @@ def main():
 
     VALID_LABELS = ["acl-config", "description", "docimpact-group",
                     "groups", "homepage", "options", "project",
-                    "upstream", "upstream-prefix", "use-storyboard"]
+                    "upstream", "upstream-prefix", "use-storyboard",
+                    "cgit-alias"]
     VALID_SCHEMES = ['https://', 'http://', 'git://']
     DESCRIPTION_REQUIRED = ['openstack', 'openstack-infra', 'openstack-dev',
                             'stackforge']
     VALID_OPTIONS = ['delay-release', 'track-upstream', 'translate']
+    CGIT_ALIAS_SITES = ['zuul-ci.org']
 
     for p in projects:
         name = p.get('project')
@@ -189,6 +191,29 @@ def main():
                 found_errors += 1
                 print("ERROR: Unknown keyword '%s' in project %s" %
                       (entry, name))
+        # Check for valid cgit aliases
+        cgit_alias = p.get('cgit_alias')
+        if cgit_alias:
+            if not isinstance(cgit_alias, dict):
+                found_errors += 1
+                print("ERROR: cgit alias in project %s must be a dict" %
+                      (name,))
+            else:
+                if 'site' not in cgit_alias or 'path' not in cgit_alias:
+                    found_errors += 1
+                    print("ERROR: cgit alias in project %s must have "
+                          "a site and path" % (name,))
+                else:
+                    site = cgit_alias['site']
+                    path = cgit_alias['path']
+                    if path.startswith('/'):
+                        found_errors += 1
+                        print("ERROR: cgit alias path in project %s must "
+                              "not begin with /" % (name,))
+                    if site not in CGIT_ALIAS_SITES:
+                        found_errors += 1
+                        print("ERROR: cgit alias site in project %s is "
+                              "not valid" % (name,))
         # Check for valid options
         for option in p.get('options', []):
             if option not in VALID_OPTIONS: