在具有多个模块的mono-repos中是否存在Go模块名称的约定？

Question

In a multi-module repository, should a module name (set via the go.mod module directive) follow the conventions of package naming?

E.g. module github.com/org-name/repo-name/path/to/module-dir

I understand that, whatever the module is named, the packages within the module refer to each other using the module name as prefix. But, from outside the module, there seems to problems if the module name is set to something other than the <host><path-within-repo> pattern. get-ing a package included in the module then gives messages about unrecognized import path.

Is there any cause to name a module differently than <host><path-within-repo> ?

Answer 1

There isn't any hard requirement for referencing modules, although it always good practice to use the domain/repo pattern. So, if you want to reference other modules locally that are not in the GOPATH, you can use the replace directive.

https://github.com/golang/go/wiki/Modules#when-should-i-use-the-replace-directive

replace also can be used to inform the go tooling of the relative or absolute on->disk location of modules in a multi-module project, such as:

replace example.com/project/foo => ../foo

Let's say we have the following structure:

├── .gitingore
├── pkg1
│   ├── go.mod
│   └── main.go
└── pkg2
    ├── go.mod
    └── utils.go

pkg1/main.go

package main

import (
    "fmt"
    "local/pkg2"
)

func main() {
    fmt.Println(pkg2.Add(1, 2))

}

pkg1/go.mod

module local/pkg1

go 1.12

require local/pkg2 v0.0.0

replace local/pkg2 => ../pkg2

pkg2/utils.go

package pkg2

func Add(a, b int) int {
    return a + b
}

pkg2/go.mod

module local/pkg2

go 1.12

Running:

cd pkg1
go run main.go

You get:

3