feat: add tag creation endpoint

artifact/artifact/v1alpha/artifact.proto

@@ -113,3 +113,23 @@ message ListRepositoryTagsResponse {
   // The requested page offset.
   int32 page = 4;
 }
+
+// CreateRepositoryTagRequest represents a request to add a tag to a given
+// repository.
+message CreateRepositoryTagRequest {
+  // The tag information.
+  RepositoryTag tag = 1;
+  // The repository holding the different versions of a given content.
+  // - Format: `repositories/{repository.id}`.
+  // - Example: `repository/flaming-wombat/llama-2-7b`.
+  string parent = 2 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {type: "api.instill.tech/Repository"}
+  ];
+}
+
+// CreateRepositoryTagResponse contains the created tag.
+message CreateRepositoryTagResponse {
+  // The created tag.
+  RepositoryTag tag = 1;
+}

artifact/artifact/v1alpha/artifact_private_service.proto

@@ -13,5 +13,15 @@ service ArtifactPrivateService {
   // Returns a portion of the versions that the specified repository holds.
   rpc ListRepositoryTags(ListRepositoryTagsRequest) returns (ListRepositoryTagsResponse);
 
+  // Create a new repository tag.
+  //
+  // Adds a tag to a given repository. Note that this operation is only
+  // intended to register the information of an *already created* tag. This
+  // method should be called as part of the content push operation, right after
+  // the [PUT Manifest](https://distribution.github.io/distribution/#put-manifest) has
+  // succeeded. The distribution registry won't hold data such as the push time
+  // or the tag digest, so `artifact-backend` will hold this information locally.
+  rpc CreateRepositoryTag(CreateRepositoryTagRequest) returns (CreateRepositoryTagResponse);
+
   option (google.api.api_visibility).restriction = "INTERNAL";
 }