Flush repository caches before renaming projects

This ensures that if a project is later re-created using the old path it
doesn't end up re-using the old cache. This also ensures we don't keep
the cache around until its expired by Redis itself.

Fixes gitlab-org/gitlab-ce#13790

app/models/project.rb

@@ -711,6 +711,8 @@ class Project < ActiveRecord::Base
     old_path_with_namespace = File.join(namespace_dir, path_was)
     new_path_with_namespace = File.join(namespace_dir, path)
 
+    expire_caches_before_rename(old_path_with_namespace)
+
     if gitlab_shell.mv_repository(old_path_with_namespace, new_path_with_namespace)
       # If repository moved successfully we need to send update instructions to users.
       # However we cannot allow rollback since we moved repository
@@ -739,6 +741,22 @@ class Project < ActiveRecord::Base
     Gitlab::UploadsTransfer.new.rename_project(path_was, path, namespace.path)
   end
 
+  # Expires various caches before a project is renamed.
+  def expire_caches_before_rename(old_path)
+    repo = Repository.new(old_path, self)
+    wiki = Repository.new("#{old_path}.wiki", self)
+
+    if repo.exists?
+      repo.expire_cache
+      repo.expire_emptiness_caches
+    end
+
+    if wiki.exists?
+      wiki.expire_cache
+      wiki.expire_emptiness_caches
+    end
+  end
+
   def hook_attrs
     {
       name: name,

spec/models/project_spec.rb

@@ -583,4 +583,67 @@ describe Project, models: true do
     end
 
   end
+
+  describe '#rename_repo' do
+    let(:project) { create(:project) }
+    let(:gitlab_shell) { Gitlab::Shell.new }
+
+    before do
+      # Project#gitlab_shell returns a new instance of Gitlab::Shell on every
+      # call. This makes testing a bit easier.
+      allow(project).to receive(:gitlab_shell).and_return(gitlab_shell)
+    end
+
+    it 'renames a repository' do
+      allow(project).to receive(:previous_changes).and_return('path' => ['foo'])
+
+      ns = project.namespace_dir
+
+      expect(gitlab_shell).to receive(:mv_repository).
+        ordered.
+        with("#{ns}/foo", "#{ns}/#{project.path}").
+        and_return(true)
+
+      expect(gitlab_shell).to receive(:mv_repository).
+        ordered.
+        with("#{ns}/foo.wiki", "#{ns}/#{project.path}.wiki").
+        and_return(true)
+
+      expect_any_instance_of(SystemHooksService).
+        to receive(:execute_hooks_for).
+        with(project, :rename)
+
+      expect_any_instance_of(Gitlab::UploadsTransfer).
+        to receive(:rename_project).
+        with('foo', project.path, ns)
+
+      expect(project).to receive(:expire_caches_before_rename)
+
+      project.rename_repo
+    end
+  end
+
+  describe '#expire_caches_before_rename' do
+    let(:project) { create(:project) }
+    let(:repo)    { double(:repo, exists?: true) }
+    let(:wiki)    { double(:wiki, exists?: true) }
+
+    it 'expires the caches of the repository and wiki' do
+      allow(Repository).to receive(:new).
+        with('foo', project).
+        and_return(repo)
+
+      allow(Repository).to receive(:new).
+        with('foo.wiki', project).
+        and_return(wiki)
+
+      expect(repo).to receive(:expire_cache)
+      expect(repo).to receive(:expire_emptiness_caches)
+
+      expect(wiki).to receive(:expire_cache)
+      expect(wiki).to receive(:expire_emptiness_caches)
+
+      project.expire_caches_before_rename('foo')
+    end
+  end
 end