ci: Introduce a cache for Gitaly binaries

Signed-off-by: Rémy Coutable <remy@rymai.me>

.gitlab/ci/global.gitlab-ci.yml

@@ -36,6 +36,27 @@
   <<: *gitaly-ruby-gems-cache
   policy: push  # We want to rebuild the cache from scratch to ensure stale dependencies are cleaned up.
 
+.gitaly-binaries-cache: &gitaly-binaries-cache
+  key:
+    files:
+      - GITALY_SERVER_VERSION
+    prefix: "gitaly-binaries"
+  paths:
+    - tmp/tests/gitaly/_build/bin/
+    - tmp/tests/gitaly/config.toml
+    - tmp/tests/gitaly/gitaly2.config.toml
+    - tmp/tests/gitaly/internal/
+    - tmp/tests/gitaly/internal_gitaly2/
+    - tmp/tests/gitaly/internal_sockets/
+    - tmp/tests/gitaly/Makefile
+    - tmp/tests/gitaly/praefect.config.toml
+    - tmp/tests/gitaly/ruby/
+  policy: pull
+
+.gitaly-binaries-cache-push: &gitaly-binaries-cache-push
+  <<: *gitaly-binaries-cache
+  policy: push  # We want to rebuild the cache from scratch to ensure stale dependencies are cleaned up.
+
 .go-pkg-cache: &go-pkg-cache
   key: "go-pkg-v1"
   paths:
@@ -97,12 +118,14 @@
   cache:
     - *ruby-gems-cache
     - *gitaly-ruby-gems-cache
+    - *gitaly-binaries-cache
     - *go-pkg-cache
 
 .setup-test-env-cache-push:
   cache:
     - *ruby-gems-cache-push
     - *gitaly-ruby-gems-cache-push
+    - *gitaly-binaries-cache-push
     - *go-pkg-cache-push
 
 .rails-cache:

scripts/gitaly-test-build

@@ -15,7 +15,12 @@ class GitalyTestBuild
   def run
     set_bundler_config
 
-    abort 'gitaly build failed' unless build_gitaly
+    # If we have the binaries from the cache, we can skip building them again
+    if File.exist?(tmp_tests_gitaly_bin_dir)
+      GitalySetup::LOGGER.debug "Gitaly binary already built. Skip building...\n"
+    else
+      abort 'gitaly build failed' unless build_gitaly
+    end
 
     ensure_gitlab_shell_secret!
     check_gitaly_config!