Tool to set or replace the go_package option in all protobuf files of a directory, according to a user-specified rule
Suppose you receive a bunch of gRPC .proto files and your task is to write a Go client for it. You will observe that it is tricky to generate correct Go code from the .proto files. Especially when the original Protobuf files import each other. That's because each .proto file needs to declare option go_package = "..." in a way that is consistent with Go's module conventions. But most Protobuf files out there either have no such option or set it to an import path that doesn't match your module name.
proto-gopackage solves this problem by enabling you to manage option go_package declarations consistently across all .proto files within a directory structure. First, it will match their package declaration against a regular expression, then it will add or update the option go_package directive according to a template.
Install using go get:
> go get -u github.com/indyjo/proto-gopackage
This will place proto-gopackage in your ~/go/bin folder.
Suppose you have a Go module named acme.com/client. Beneath its main directory, there is s folder named proto/ which contains a bunch of proto files, some of those provided by your company, Acme Corp.. Those .proto files haven't been prepared for Go, so they're lacking proper option go_package declarations.
> proto-gopackage -package 'acme\.(.*)' -go_package 'acme.com/client/proto/acme/{{index . 1}}' ./proto
The above command will scan through folder ./proto, setting (or replacing) option go_package in all .proto files whose package declaration starts with acme.. Notice that package substrings containing a dot . will automatically be converted to slash / when inserted into option go_package.
Some .proto files have versioned packages, that is they declare a package suffixed by a version. Something like acme.logging.v2. You might want those packages to receive an option go_package in extended format like acme.com/client/proto/logging/v2;logging. Easy with the following command:
> proto-gopackage -package 'acme\.(.*)\.([^.]+)\.(v.)' -go_package 'acme.com/client/proto/acme/{{index . 1}}/{{index . 2}}/{{index . 3}};{{index . 2}}' ./proto