Working with Go in Bazel

Dependencies

Go dependencies are managed by go.mod and Gazelle. To add a new Go dependency

Run go get to add the dependency to go.mod. E.g.
```
go get github.com/envoyproxy/[email protected]
```
This should update go.mod and go.sum.
Run Gazelle to import the dependencies to Bazel.
```
bazel run //:gazelle-update-repos
```
This should update go_deps.bzl.