1 files changed, 52 insertions, 0 deletions
diff --git a/app/services/dependency_proxy/find_or_create_manifest_service.rb b/app/services/dependency_proxy/find_or_create_manifest_service.rb
new file mode 100644
index 00000000000..6b46f5e4c59
--- /dev/null
+++ b/app/services/dependency_proxy/find_or_create_manifest_service.rb
@@ -0,0 +1,52 @@
+# frozen_string_literal: true
+
+module DependencyProxy
+  class FindOrCreateManifestService < DependencyProxy::BaseService
+    def initialize(group, image, tag, token)
+      @group = group
+      @image = image
+      @tag = tag
+      @token = token
+      @file_name = "#{@image}:#{@tag}.json"
+      @manifest = nil
+    end
+
+    def execute
+      @manifest = @group.dependency_proxy_manifests
+                        .find_or_initialize_by_file_name(@file_name)
+
+      head_result = DependencyProxy::HeadManifestService.new(@image, @tag, @token).execute
+
+      return success(manifest: @manifest) if cached_manifest_matches?(head_result)
+
+      pull_new_manifest
+      respond
+    rescue Timeout::Error, *Gitlab::HTTP::HTTP_ERRORS
+      respond
+    end
+
+    private
+
+    def pull_new_manifest
+      DependencyProxy::PullManifestService.new(@image, @tag, @token).execute_with_manifest do |new_manifest|
+        @manifest.update!(
+          digest: new_manifest[:digest],
+          file: new_manifest[:file],
+          size: new_manifest[:file].size
+        )
+      end
+    end
+
+    def cached_manifest_matches?(head_result)
+      @manifest && @manifest.digest == head_result[:digest]
+    end
+
+    def respond
+      if @manifest.persisted?
+        success(manifest: @manifest)
+      else
+        error('Failed to download the manifest from the external registry', 503)
+      end
+    end
+  end
+end