Review incorrect go module usage

[cep21]

Hi,

I ran into the following issue using this client with go and modules.

build github.com/my/service: cannot load github.com/cactus/go-statsd-client/statsd: ambiguous import: found github.com/cactus/go-statsd-client/statsd in multiple modules:
    github.com/cactus/go-statsd-client v3.1.1+incompatible (/Users/jlindamo/go/pkg/mod/github.com/cactus/go-statsd-client@v3.1.1+incompatible/statsd)
    github.com/cactus/go-statsd-client/statsd v0.0.0-20190501063751-9a7692639588 (/Users/jlindamo/go/pkg/mod/github.com/cactus/go-statsd-client/statsd@v0.0.0-20190501063751-9a7692639588)

This doesn't happen if you're directly referencing this client, but can if multiple libraries are referencing the client in different ways and you're trying to use both libraries at once.

I don't think the change to add the go.mod file was correct: https://github.com/cactus/go-statsd-client/blob/master/statsd/go.mod

With go.mod, since you're on tag v3, the path of everything inside there should be github.com/cactus/go-statsd-client/statsd/v3 instead of github.com/cactus/go-statsd-client/statsd. That includes the go.mod file as well.

It may be best to either add v3 to the path in the module file, or remove the go.mod file.

[cep21]

CC: @manaspaldhe12

[dropwhile]

There is some unclear documentation on the go site in regards to the placement of go.mod.
For example, this documentation wiki makes it sound like like even though the go-statsd-client is never used as a top level import (eg. import "github.com/cactus/go-statsd-client") that the go.mod should go at the top level anyway. That's a bit strange...

This page seems to present conflicting information:

A module is defined by a tree of Go source files with a go.mod file in the tree's root directory. The directory containing the go.mod file is called the module root. Typically the module root will also correspond to a source code repository root (but in general it need not). The module is the set of all Go packages in the module root and its subdirectories, but excluding subtrees with their own go.mod files.

Perhaps you can post the go.mod for the project that raised the error?
Maybe that go.mod file has a dep pinned for github.com/cactus/go-statsd-client instead of for github.com/cactus/go-statsd-client/statsd?

[dropwhile]

no feedback. closing for now. reopen if needed.