From 89833915c7c5d66ab5952ca1daf85e99ca3ca14b Mon Sep 17 00:00:00 2001
From: John Cai <jcai@gitlab.com>
Date: Fri, 18 Jul 2025 16:40:10 -0400
Subject: [PATCH] gitaly: Set the grpc-encoding header

Set the grpc-encoding header to turn on grpc compression. Gate this by a
feature flag so we can test the effects of turning this on.
---
 .../undefined/gitaly_use_gzip_compression.yml            | 8 ++++++++
 lib/gitlab/gitaly_client.rb                              | 7 ++++---
 spec/lib/gitlab/gitaly_client_spec.rb                    | 9 ++++++++-
 3 files changed, 20 insertions(+), 4 deletions(-)
 create mode 100644 config/feature_flags/undefined/gitaly_use_gzip_compression.yml

diff --git a/config/feature_flags/undefined/gitaly_use_gzip_compression.yml b/config/feature_flags/undefined/gitaly_use_gzip_compression.yml
new file mode 100644
index 00000000000000..7b5ea12e347115
--- /dev/null
+++ b/config/feature_flags/undefined/gitaly_use_gzip_compression.yml
@@ -0,0 +1,8 @@
+---
+name: gitaly_use_gzip_compression
+introduced_by_url:
+rollout_issue_url:
+milestone:
+type: undefined
+group: group::gitaly
+default_enabled: false
diff --git a/lib/gitlab/gitaly_client.rb b/lib/gitlab/gitaly_client.rb
index 9593e1369b6a42..ed030ac618bcff 100644
--- a/lib/gitlab/gitaly_client.rb
+++ b/lib/gitlab/gitaly_client.rb
@@ -286,7 +286,7 @@ def self.execute(storage, service, rpc, request, remote_storage:, timeout:, gita
       Gitlab::RequestContext.instance.ensure_deadline_not_exceeded!
       raise_if_concurrent_ruby!
 
-      kwargs = request_kwargs(storage, timeout: timeout.to_f, remote_storage: remote_storage, gitaly_context: gitaly_context)
+      kwargs = request_kwargs(storage, timeout: timeout.to_f, remote_storage: remote_storage, gitaly_context: gitaly_context, rpc: rpc)
       kwargs = yield(kwargs) if block_given?
 
       stub(service, storage).__send__(rpc, request, kwargs) # rubocop:disable GitlabSecurity/PublicSend
@@ -324,7 +324,7 @@ def self.authorization_token(storage)
     end
     private_class_method :authorization_token
 
-    def self.request_kwargs(storage, timeout:, remote_storage: nil, gitaly_context: {})
+    def self.request_kwargs(storage, timeout:, remote_storage: nil, gitaly_context: {}, rpc: nil)
       metadata = {
         'authorization' => "Bearer #{authorization_token(storage)}",
         'client_name' => CLIENT_NAME
@@ -349,8 +349,9 @@ def self.request_kwargs(storage, timeout:, remote_storage: nil, gitaly_context:
       metadata['remote_ip'] = context_data['meta.remote_ip'] if context_data&.fetch('meta.remote_ip', nil)
       metadata['relative-path-bin'] = relative_path if relative_path
       metadata['gitaly-client-context-bin'] = gitaly_context.to_json if gitaly_context.present?
-
+      metadata['grpc-accept-encoding'] = 'gzip' if Feature::Gitaly.enabled_for_any?(:gitaly_use_gzip_compression)
       metadata.merge!(Feature::Gitaly.server_feature_flags(**feature_flag_actors))
+
       metadata.merge!(route_to_primary)
 
       deadline_info = request_deadline(timeout)
diff --git a/spec/lib/gitlab/gitaly_client_spec.rb b/spec/lib/gitlab/gitaly_client_spec.rb
index 856d1bb1e84cd9..71225d3dfa4cab 100644
--- a/spec/lib/gitlab/gitaly_client_spec.rb
+++ b/spec/lib/gitlab/gitaly_client_spec.rb
@@ -394,6 +394,12 @@ def stub_repos_storages(address)
       expect(results[:metadata]).to include('gitaly-session-id')
     end
 
+    it 'sets grpc-accept-encoding to gzip' do
+      kwargs = described_class.request_kwargs('default', timeout: 1)
+
+      expect(kwargs[:metadata]['grpc-accept-encoding']).to eq('gzip')
+    end
+
     context 'with gitaly_context' do
       let(:gitaly_context) { { key: :value } }
 
@@ -1023,7 +1029,8 @@ def call_gitaly(count = 1)
 
       it 'passes the gitaly_context to .request_kwargs' do
         expect(described_class).to receive(:request_kwargs).with(
-          'default', timeout: 10.seconds, remote_storage: nil, gitaly_context: gitaly_context
+          'default', timeout: 10.seconds, remote_storage: nil, gitaly_context: gitaly_context,
+          rpc: :find_local_branches
         ).and_call_original
 
         execute
-- 
GitLab