twitchtv/twirp v7.0.0

on GitHub

Twirp v7 is a major release that includes a protocol spec update. The jump from v5 to v7 is to avoid confusion with the archived protocol spec v6 that was not released.

Changes in the protocol spec from v5 to v7:

• Twirp routes can have any prefix: <prefix>/<package>.<Service>/<Method>. In v5 the prefix was mandatory, always/twirp.
• Error code ResourceExhausted maps to HTTP code 429. In v5 it mapped to 403.

Changes in the Go Twirp v7.0.0 release:

• #264 Optional Twirp Prefix. Implements the proposal #263 with the optional prefix, using an option to specify a different prefix than the default value "/twirp". The default value ensures backwards compatibility when updating the service. Using different prefixes, it is now possible to mount the same Twirp service in multiple routes, which may help migrating existing services from the "/twirp" prefix to a new one.
• #264 also introduces server options on the server constructor, that can be used to setup hooks and new options like the path prefix.
• #270 ResourceExhausted error code changed to 429 HTTP status code. This may affect middleware if it depends on a specific status code being used.
• #271 Server JSON responses using EmitDefaults: responses include all fields, even if they have zero-values. This can be reverted to the previous behavior (skip zero-values) with the server option: twirp.WithServerJSONSkipDefaults(true).
• #257 Go services handle literal routes. Fixing part of the issue #244, affecting cross-language communications when the proto definitions are not using the recommended Protobuf Style Guide.
• #268 Bufgfix: Allow to update context from server Error hooks, so they can communicate with the ResponseSent hook if needed.

Go Upgrade instructions

For the most part, the upgrade to the new version should work out of the box. But there are a few areas to pay attention, depending if your service is using some specific features or not.

Twirp has two components, the twirp package and the code generator plugin (protoc-gen-twirp). One thing is to upgrade the package to the latest version, and another thing is to re-generate the server/client code with the latest version. You should upgrade the package first, because it works with older generated clients.

Upgrade the twirp package to version v7.0.0 in your project.

• If you are explicitly using twirp.ServerHTTPStatusFromErrorCode(twirp.ResourceExhausted), the returned value will change from 403 to 429.
• If your service is returning errors with the code twirp.ResourceExhausted and you have middleware and/or monitoring tools that depend on the HTTP status code, they will now see a change from 403 to 429.

Generate code with version v7+ of the plugin protoc-gen-twirp.

• If your service is serving JSON requests under heavy traffic requirements, make sure to skip defaults with the option twirp.WithServerJSONSkipDefaults(true). Pass this option as an extra argument to the New<Service>Server constructor. See more details on #271

Importing Twirp clients from other services:

• If your service is importing Twirp clients from other services that were generated in older versions, don't worry, they still work.
• The new v7 package works for clients that were generated with the older v5 generator.
• But the new v7 clients require the new v7 package to compile.
• If you have multiple services that depend on each other, update the twirp package on all services first. Don't re-generate the code yet. Once all services have the v7 package, you can update the protoc-gen-twirp to v7 and re-generate all clients.