grpc-any

grpc-any Example

Use the gRPC (google.protobuf.Any) type to pass an arbitrary type across a pseudo call boundary.

Note: there are older, historical ways. This package attempts to implement the current best practice, as of 2/2022.

• https://pkg.go.dev/google.golang.org/protobuf@v1.27.1/types/known/anypb

Some learning(s) along the way:

Install BOTH protoc and the associated includes

The protoc compiler (https://github.com/protocolbuffers/protobuf) comes with two things:

1. protoc the IDL compiler
2. Include protobuf files (.proto's)

If you are only compiling IDL you generated then only protoc is required. IF you wish to add core protobuf types, like Any, then you need the includes as well.

Download the protobuff-all-x.y.z.tar.gz file, it includes both.

Docs: https://grpc.io/docs/protoc-installation/

Golang - the golang plugin

Each language requires a language specific plugin to generate protobuf stubs for that language.

• https://developers.google.com/protocol-buffers/docs/reference/go-generated

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

The above will install protoc-gen-go, the golang plugin, into your $GOBIN directory.

Golang libraries

Additional golang libraries are needed. The google.golang.org/protobuf packages are newer, and preferred over (the deprecated) github.com/golang/protobuf packages.

• https://pkg.go.dev/google.golang.org/protobuf@v1.27.1/types/known/anypb

The anypb package contains documentation describing how to marshal and unmarshal between compiled (concrete) protobuf types and the any type. (as does this example)