Temporal Activity Protobuf Generator Proof of Concept

This is a protoc plugin for generating easy to use code for calling and implementing activities.

This is not an official Temporal product

This generator converts protobuf services to easy to use Temporal activity code. Specifically a struct is generated for calling activities and an interface is generated for implementing them.

See the example to see how it can be used.

Usage

This is similar to the gRPC quick start

This requires Go installed, and protoc installed and on the PATH.

If not already installed, the protobuf Go code generator should be installed with:

go install google.golang.org/protobuf/cmd/protoc-gen-go@latest

Similarly, this code generator should also be installed with:

go install github.com/cretz/temporal-protoc-gen-go-activity/protoc-gen-go-activity@latest

The Go bin also needs to be on the PATH for those two protoc-gen binaries to be seen by protoc. For example, on Linux:

export PATH="$PATH:$(go env GOPATH)/bin"

Now protoc can be used with both --go_out and --go-activity_out and Temporal code will be written. See the example for a sample of its use.

Additional Notes

• This is just a proof of concept showing how to use protobuf services. It is not a robust code generator.
• By default, the Temporal Go SDK will use protobuf JSON serialization for activity request/response. While this is much more human friendly to external readers, it is less resilient to field name changes than traditional binary protobuf serialization which only cares about field numbers. If binary serialization is preferred, the data converter can be set to converter.NewCompositeDataConverter(converter.NewProtoPayloadConverter()) (but this loses fallback converters, so instead one may just want to reorder what's in the default).
• While the activity struct has synchronous invocations, futures can still be used by still using ExecuteActivity passing the function reference (e.g. workflow.ExecuteActivity(ctx, MyService.MyRPC, req)).