Use Gitea for Gerrit's code browser URLs

This is a reimplementation of earlier change
I8efefe365f3b9ebe97c8c2ce322fa8c6f3b70b3a to link out to Gitea
instead of Gerrit's local Gitiles plugin. This should reduce the
complexity of what we're hosting on the Gerrit server, while at the
same time be less confusing for search engines and users. Configure
the Gitiles plugin to no longer take over Gerrit weblinks, and a
followup change will block access to its URL base path entirely.

Change-Id: I7e194fe5c907b39d53fd0663e06cbfd33a3ae410

playbooks/roles/gerrit/files/gitiles.config

@@ -0,0 +1,2 @@
+[gerrit]
+	noWebLinks = true

playbooks/roles/gerrit/tasks/main.yaml

@@ -215,6 +215,14 @@
     group: '{{ gerrit_user_name }}'
     mode: 0644
 
+- name: Write Gitiles plugin configuration file
+  copy:
+    src: gitiles.config
+    dest: '{{ gerrit_site_dir }}/etc/gitiles.config'
+    owner: '{{ gerrit_user_name }}'
+    group: '{{ gerrit_user_name }}'
+    mode: 0644
+
 - name: Write manage-projects script
   template:
     src: "manage-projects.j2"

playbooks/roles/gerrit/templates/gerrit.config.j2

@@ -131,13 +131,19 @@
 	system = Storyboard
 [plugin "javamelody"]
 	allowTopMenu = false
-# Gerrit upstream hardcodes a .git extension for cgit.
+# Custom code browser linking for Gitea.
-# The cgit settings below are the same just without the
-# .git extension.
 [gitweb]
-	type = gitweb
+	branch = "${project}/src/branch/${branch}"
-	cgi = /usr/share/gitweb/gitweb.cgi
+	file = "${project}/src/commit/${hash}/${file}"
-	revision = "?p=${project}.git;a=commitdiff;h=${commit}"
+	filehistory = "${project}/commits/branch/${branch}/${file}"
+	linkname = gitea
+	project = "${project}"
+	revision = "${project}/commit/${commit}"
+	roottree = "${project}/src/commit/${commit}"
+	type = custom
+	urlEncode = false
+	tag = "${project}/src/tag/${tag}"
+	url = "https://opendev.org/"
 [index]
 	type = LUCENE
 	threads = 8