Go for Node developers

I'm developing Node apps for years and started working with Go last month. So far, I like it as much as I like Node. So I hope to blog some quick tips about Go (aka Golang) for Node developers starting with the $GOPATH. I'll start with some boring stuff and quickly move on to something useful. If you haven't tried go yet, this is a good page to start.

The $GOPATH

It's sort of like one path to rule them all solution. All your Go projects and their dependencies go here. This is a bit different from node_modules. The $GOPATH contains following directories.

bin/  # compiled binaries
pkg/  # compiled non-binary packages
src/  # package source files

And there are several approaches to managing the $GOPATH.

Per-app $GOPATH

This is the way I tried first because it was similar to having a node_modules directory. Your project would look something like this.

bin/
pkg/
src/
  app/         # app source files
    main.go
    ...
  github.com/  # dependencies
  ...

When checking into a repo, add the complete $GOPATH with all dependencies. Add the bin and pkg directories to your .gitignore file. This way you will have all your dependency versions fixed. The bad side of this approach is that you'll have to set the $GOPATH environment variable quite a lot. This can get pretty annoying. And you may work with an incorrect $GOPATH by mistake.

Global $GOPATH

Others use a common $GOPATH for all their projects. Dependencies are usually kept to their latest versions. I know this sounds like installing everything globally with npm. Anyways, it's not as bad as it would be if we're doing this with Node. Mostly because Go applications wouldn't have many external dependencies (compare that to Node).

bin/
pkg/
src/
  github.com/
    username/
      app-1/
        main.go
        ...
      app-2/
        main.go
        ...

I'm not really feeling comfortable with mixing everything but it usually gets the job done. If you're starting with Go, don't waste time worrying about versions and go ahead with a common $GOPATH.

Global $GOPATH with Godeps

Another way to manage dependencies is vendoring. It can be done easily with Godep. With Godeps you can create a snapshot of all your dependencies. This successfully freezes dependencies to the exact version. It also saves a copy of all dependencies so you don't need to worry if the author takes the repo down (... maybe you should).

More about Godep