Provide a vendor directory to avoid downloading all go modules when execute "go build"

[Mingli-Yu]

After fetch the cni code via "git clone git://github.com/containernetworking/cni.git" and then continue to build the code via "go build", but it still try to fetch the dependencies defined in ../cni/go.module after a7cceb9 included in go 1.15. It's better to provide a vendor directory to avoid downloading all go modules when execute "go build".
go version: 1.15
cni version: v0.8.0

[antoninbas]

I'm no expert but projects that use Go modules typically no longer include a vendor directory. So I'm not sure it is "better to provide a vendor directory". See the "End of Vendoring" in https://research.swtch.com/vgo-module. The community seems to be transitioning to self-hosted or public proxies such as https://github.com/gomods/athens to ensure availability of dependencies or enable "offline" builds. You may also build your own vendor directory, with the caveat that vendor diectories are ignored by go build by default unless you provide -mod vendor.

[Mingli-Yu]

@antoninbas, thanks your response, yes, I just want to enable offline build.

[bboreham]

Please explain what you built using go build. This repo is primarily a library.

[Mingli-Yu]

@bboreham
Yes, I indeed know the cni is a library and there is another package depends on cni in my build environment, so I need to run build against cni and want to do a offline build in my env. Thanks!

[bboreham]

Ok so the vendor directory would be in your project not in ours.

[Mingli-Yu]

@bboreham,
Thanks your response, but I don't understand what you mean. Initially I open the issue is because I clone the cni code via "git clone git://github.com/containernetworking/cni.git" and then continue to run "go build", but don't want it connect the network to fetch the dependencies defined in go.mod file for cni during "go build" phase, is there any means? Thanks in advance!

[bboreham]

I clone the cni code via "git clone git://github.com/containernetworking/cni.git" and then continue to run "go build"

If I do this it says "no Go files in /home/vagrant/src/github.com/containernetworking/cni".

What you indicated before is that you are building your own project, which will say something like import "github.com/containernetworking/cni/pkg/types/current". And you can have a vendor directory in that project.

As described at https://golang.org/ref/mod#vendoring, "the go command ignores vendor directories in locations other than the main module's root directory", so even if we did what you asked it would not change anything. The "main module" is whatever you are building; the CNI library is not your main module.

[Mingli-Yu]

@bboreham,
1, mkdir -p $GOPATH/src/github.com/containernetworking
2, cd $GOPATH/src/github.com/containernetworking
3, git clone git://github.com/containernetworking/cni.git
4, cd cni/libcni
5, go build

[bboreham]

This is not something you need to do, or should do.
Just import the package(s) and build your project in its directory; Go will compile all dependencies.

[Mingli-Yu]

@bboreham,
Thanks very much for your response!
Actually I don't quite understand what you mean when you say "This is not something you need to do, or should do."

In my env, it's easy to reproduce that it needs to connect the network during "go build" stage with below steps. And all I want just provide a method not let it connect the network during "go build" stage. Thanks a lot!
1, mkdir -p $GOPATH/src/github.com/containernetworking
2, cd $GOPATH/src/github.com/containernetworking
3, git clone git://github.com/containernetworking/cni.git
4, cd cni/libcni
5, go build