golang offline install third party package

I'm trying to install third party package of golang in offline.
I want to do something like go get <third party package> in an online environment in an offline environment. I can get the source of the third party package from github and put it in an offline environment, but then I can't use it as a package in golang.

What should i do?

As @emptyhua commented, this link worked for me: https://gist.github.com/gmolveau/f09c1038ca622620e54d0579ba06ea96#file-golang_offline-md

For reference here:

1. On the online machine ensure go.mod and go.sum exist in current dir
   create a go file with:

import (
	_ "github.com/gorilla/mux"
	_ "github.com/sirupsen/logrus"
)

func main() {}

2. run: go mod vendor

3. Copy go.mod, go.sum and vendor directory to the offline machine

4. run: go run -mod=vendor main.go

To test offline, I used a container with no network:
podman run --rm -it --net none -v $(pwd):/go/src:z golang

cd src
go run -mod=vendor main.go

Hope that helps! Thanks @gmolveau - offline go mods

You can try the vendor/ directory.

See my answer at https://stackoverflow.com/a/76688264/490291

If the package is part of Debian, perhaps even following is enough:

ln -s /usr/share/gocode/src vendor

A package github.com/$USER/$REPO is searched at vendor/github.com/$USER/$REPO/, such that you can even use git submodule for checking out the package:

git submodule add https://github.com/$USER/$REPO.git vendor/github.com/$USER/$REPO/

> AFAICS (but I never tried it) git submodule update --recursive does not work here as expected. So if some submodule has a vendor/ directory itself, you must mix this into your own vendor/ directory, as this feature does not do recursion. At least that is the impression I got from the (too scarce) documentation about that feature.
>
> You can use softlinks to map the sub-paths, of course, like with
> bash
> yes n | for a in vendor/*/*/*/vendor/*; do [ -d "$a" ] && ln -is --relative "$a"/* "vendor/`basename "$a"`/"; done
>

There is a less known git feature which allows you to map any URL to anything. So for example if you did a mirror (something you can copy to your servers with your provisioning tool or rsync):

git clone --mirror https://github.com/$USER/$REPO.git /srv/git/github.com/$USER/$REPO.git

you can map https://github.com/$USER/$REPO.git to /srv/git/github.com/$USER/$REPO.git with a single line:

git config --global url./srv/git/github.com/.insteadOf https://github.com/

> So:
>
> - On some remote networked PC do all the --mirror cloning
> - Copy the mirrored repositories to /srv/git/ on the offlined PC
> - Then do git config --global url./srv/git/.insteadOf https://
> - Then do the git submodule add into vendor/
>
> Or git clone --recursive /srv/git/yoursource.git which already has the .gitmodules file in place, which carries https://github.com/-URLs which only work outside of the offline environment, but work offline, too, as they are remapped to /srv/git/

Note that you can map all http:// and https:// URLs this way, such that https://$SERVER/$USER/$REPO.git becomes /srv/git/$SERVER/$USER/$REPO.git with

git config --global url./srv/git/.insteadOf https://
git config --global url./srv/git/.insteadOf http://

The only thing you need to remember is: Do not leave the suffix .git away in your checkouts/submodule URLs. And do not add a trailing /.

This usually makes live much easier. Because you usually want to name "bare" git repositories (--mirror) something.git and not something, as usually something/ should be the checkout of a worktree. As git is intelligent enough to remove the .git in most cases, and all git services like GitHub or GitLab do this, too, adding the .git only adds benefits when remapping, because you can map something.git and something-wiki.git differently (without extension something includes something-wiki).

The git feature url.*.insteadOf only maps the prefix, you cannot change the suffix as easily as well. So if you happen to need to add a suffix, you must remap each URL individually, which makes things uncomfortable. Also I consider ending git repo URLs on .git to look much more natural. YMMV.

First of all, you have to set the GOPATH for the working directory.
After then you can use the following offline package just you have to create a mod file for the path of the packages.

Initialize go mod file using below code

go mod init <Enter your GitHub profile link>

For example:

go mod init github.com/amshashankk

after this when you import the packages they will be written as following in the import section of the code

github.com/amshashankk/package.