Want to contribute? Great! First, read this page.

Contributor License Agreement

Contributions to this project must be accompanied by a Contributor License Agreement. You (or your employer) retain the copyright to your contribution; this simply gives us permission to use and redistribute your contributions as part of the project. Head over to https://cla.developers.google.com/ to see your current agreements on file or to sign a new one.

You generally only need to submit a CLA once, so if you‘ve already submitted one (even if it was for a different project), you probably don’t need to do it again.

Using GOPATH

Some editors may require the code to be structured in a GOPATH directory tree. In this case, you may use the :gopath target to generate a directory tree with symlinks to the original source files.

bazel build :gopath

You can then set the GOPATH in your editor to bazel-bin/gopath.

If you use this mechanism, keep in mind that the generated tree is not the canonical source. You will still need to build and test with bazel. New files will need to be added to the appropriate BUILD files, and the :gopath target will need to be re-run to generate appropriate symlinks in the GOPATH directory tree.

Coding Guidelines

All Go code should conform to the Go style guidelines. C++ code should conform to the Google C++ Style Guide and the guidelines described for tests.

As a secure runtime, we need to maintain the safety of all of code included in gVisor. The following rules help mitigate issues.

Definitions for the rules below:

core:

  • //pkg/sentry/...
  • Transitive dependencies in //pkg/..., //third_party/....

runsc:

  • //runsc/...

Rules:

  • No cgo in core or runsc. The final binary must be a statically-linked pure Go binary.

  • Any files importing “unsafe” must have a name ending in _unsafe.go.

  • core may only depend on the following packages:

    • Itself.
    • Go standard library.
      • Except (transitively) package “net” (this will result in a non-cgo binary). Use //pkg/unet instead.
    • @org_golang_x_sys//unix:go_default_library (Go import golang.org/x/sys/unix).
    • Generated Go protobuf packages.
    • @com_github_golang_protobuf//proto:go_default_library (Go import github.com/golang/protobuf/proto).
    • @com_github_golang_protobuf//ptypes:go_default_library (Go import github.com/golang/protobuf/ptypes).
  • runsc may only depend on the following packages:

    • All packages allowed for core.
    • @com_github_google_subcommands//:go_default_library (Go import github.com/google/subcommands).
    • @com_github_opencontainers_runtime_spec//specs_go:go_default_library (Go import github.com/opencontainers/runtime-spec/specs_go).

Code reviews

All changes must be submitted via Gerrit.

All submissions, including submissions by project members, require review.

To submit a patch, first clone the canonical repository.

git clone https://gvisor.googlesource.com/gvisor

From within the cloned directory, install the commit hooks (optional, but if you don't you will need to generate Change-Ids manually in your commits).

curl -Lo `git rev-parse --git-dir`/hooks/commit-msg https://gerrit-review.googlesource.com/tools/hooks/commit-msg
chmod +x `git rev-parse --git-dir`/hooks/commit-msg

Edit the source and generate commits as you normally would. While making changes, remember to organize commits logically. Changes are not reviewed per branch (as with a pull request), they are reviewed per commit.

Before posting a new patch, you will need to generate an appropriate authentication cookie. Visit the repository and click the “Generate Password” link at the top of the page for instructions.

To post a patch for review, push to a special “for” reference.

git push origin HEAD:refs/for/master

A change link will be generated for the commit, and a team member will review your change request, provide feedback (and submit when appropriate).

If you receive an error like No Contributor Agreement on file for user ..., make sure you've signed the CLA.

To address feedback, you may need to amend your commit and repush (don't change the Commit-Id in the commit message). This will generate a new version of the change.

When approved, the change will be submitted by a team member and automatically merged into the repository.

The small print

Contributions made by corporations are covered by a different agreement than the one above, the Software Grant and Corporate Contributor License Agreement.