dep2nix converts a Gopkgs.lock file into a deps.nix file which is understood by nixpkgs's go abstraction thanks to go2nix effort.

In other words: For go projects using golang dep already, it is fairly trivial to get these projects to compile with Nix/NixOS.

git clone https://github.com/nixcloud/dep2nix
cd dep2nix
nix-env -f default.nix -i dep2nix
nix-env -i nix-prefetch-git    (this step might not be needed anymore soon)

cd yourproject   (contains the Gopkg.lock)

dep2nix
Found 14 libraries to process: 
github.com/Masterminds/semver github.com/Masterminds/vcs github.com/armon/go-radix github.com/boltdb/bolt github.com/golang/dep github.com/golang/protobuf github.com/jmank88/nuts github.com/nightlyone/lockfile github.com/pelletier/go-toml github.com/pkg/errors github.com/sdboyer/constext golang.org/x/net golang.org/x/sync golang.org/x/sys 

* Processing: "github.com/Masterminds/semver"
* Processing: "github.com/Masterminds/vcs"
* Processing: "github.com/armon/go-radix"
* Processing: "github.com/boltdb/bolt"
* Processing: "github.com/golang/dep"
* Processing: "github.com/golang/protobuf"
* Processing: "github.com/jmank88/nuts"
* Processing: "github.com/nightlyone/lockfile"
* Processing: "github.com/pelletier/go-toml"
* Processing: "github.com/pkg/errors"
* Processing: "github.com/sdboyer/constext"
* Processing: "golang.org/x/net"
* Processing: "golang.org/x/sync"
* Processing: "golang.org/x/sys"

-> Wrote deps.nix, everything fine!

dep2nix has created a deps.nix file similar to the one originally created by go2nix tool. If you wonder how to compile your GO based project with nixpkgs just look into the source code of this project itself at https://github.com/nixcloud/dep2nix

Note: It is good practice to keep the Gopkg.lock, Gopkg.toml as well as the deps.nix in the GIT repository of your project.

nix-shell -p go dep
cd yourproject
dep init
dep2nix

On one test machine dep2nix wouldn't build with the error that lockfile had a 'wrong' sha256:

{
  goPackagePath  = "github.com/nightlyone/lockfile";
  fetch = {
    type = "git";
    url = "https://github.com/nightlyone/lockfile";
    rev =  "6a197d5ea61168f2ac821de2b7f011b250904900";
    sha256 = "0z3bdl5hb7nq2pqx7zy0r47bcdvjw0y11jjphv7k0s09ahlnac29";
  };
}

But running nix-prefetch-git --url https://github.com/nightlyone/lockfile --rev 6a197d5ea61168f2ac821de2b7f011b250904900 showed it was actually correct.

After running nix-build it showed the /nix/store/krjm0nanydmyyddx222vn443hq13fsis-dep2nix.drv target and then this call:

nix-store --delete /nix/store/krjm0nanydmyyddx222vn443hq13fsis-dep2nix.drv

Resets the complete build artifacts and afterwards it was working. No clue what is going on there...

returns bogus for not existent git repos as golang.org/x/net for example, this needs to return at least erropr code != 0

• NixOS/nixpkgs#35017

• add hashes to dependencies (hash per git repo)

  • this is similar to yarn2nix / yarn.lock way):

    there they are using tar.bz2 bundles but from the npm registry IIRC

    • https://github.com/moretea/yarn2nix/blob/master/yarn.lock
    • https://github.com/moretea/yarn2nix/blob/master/yarn.nix

    note: since npm is used they don't use github for binary downloads this works but there are lots of issues as pointed out in this issue report for example easybuilders/easybuild-easyconfigs#5151

  and is discussed for golang dep here:

  • golang/dep#121
  • golang/dep#278

  conclusion: if we had hashes in the Gopkgs.lock, we wouldn't need go2nix and no more duplicated git clones as well as maintainer work to update the Gopkgs.lock -> deps.nix at all.

  this would require:

  • https://lethalman.blogspot.de/2014/08/nix-pill-9-automatic-runtime.html (NAR discussion)
  • https://github.com/NixOS/nixpkgs/blob/master/pkgs/build-support/fetchgit/nix-prefetch-git
  • https://stackoverflow.com/questions/1713214/how-to-use-c-in-go
  • https://github.com/NixOS/nix/blob/master/src/libutil/hash.cc

See LICENSE file.

• integrate into nixpkgs, add nix-prefetch-url as dependency for this tool

  • https://blog.golang.org/generate

      joachim@lenovo-t530 ~/D/p/n/nixpkgs> git grep 'go generate'
      pkgs/applications/networking/gopher/gopherclient/default.nix:    PATH="$(pwd):$PATH" go generate ${goPackagePath}
      pkgs/applications/version-management/git-lfs/1.nix:      go generate ./commands
      pkgs/applications/version-management/git-lfs/default.nix:    go generate ./commands
      pkgs/development/interpreters/joker/default.nix:  preBuild = "go generate ./...";
      pkgs/development/tools/continuous-integration/drone/default.nix:    go generate github.com/drone/drone/server/template
      pkgs/development/tools/continuous-integration/drone/default.nix:    go generate github.com/drone/drone/store/datastore/ddl
      pkgs/development/tools/go2nix/default.nix:  preBuild = ''go generate ./...'';
      pkgs/development/tools/kube-aws/default.nix:    go generate ./core/controlplane/config
      pkgs/development/tools/kube-aws/default.nix:    go generate ./core/nodepool/config
      pkgs/development/tools/kube-aws/default.nix:    go generate ./core/root/config
      pkgs/servers/monitoring/mtail/default.nix:  preBuild = "go generate -x ./go/src/github.com/google/mtail/vm/";
    

• add Flags:

• check to not overwrite the deps.nix if already there

• help

• also write 'incomplete' deps.nix (with 1 exit code and warning) if dependencies using nix-prefetch-url fail

• test with leaps

• blog this