Bazel External Deps Roadmap

Last verified: 2018-07-17 (Update history)

Point of contact: dslomov

Roadmap for improving external dependencies support and integration with package managers and other build systems in Bazel.


External dependencies work fall into three broad categories:

  1. General improvements for WORKSPACE support in Bazel (see External Repositories: The Future for general background and discussion).

  2. Allowing Bazel project to depend on other projects built with a different build tool and/or available through a package manager.
    • bazel-deps is one tool that provide that support.
    • A good analysis of challenges with C++ dependencies has been done by Envoy project.
  3. Allowing other build systems to depend on Bazel project.
    • Generally this includes features such as
      • plugins for other build systems invoking Bazel
      • publishing Bazel-built artifacts so that they can be used by other build systems
      • generating project files for other build systems
    • The full set of features needed for this is currently forming. (We welcome your input on bazel-discuss@)

2018 Q2

  1. General improvements for WORKSPACE support in Bazel
  2. Bazel depends on 3rd-party

2018 Q3

  1. General improvements for WORKSPACE support in Bazel
    • Document curent state and best practices for BUILD files that can be used both as main and external repository, decide on whether the change to exec root layout is needed
    • Implement WORKSPACE/WORKSPACE.resolved split, so that users can easily upgrade and share their dependencies in a controlled and well-defined way
    • Technical plan for recursive workspaces: convenient way for users to manage transitive dependencies
  2. Bazel depends on 3rd-party
    • Provide rules for cmake and other C++ build systems
      • Validation: Envoy is able to switch to these rules for their cmake dependecies.
    • Integrate bazel-deps into WORKSPACE.resolved so that users don’t have to run it as a separate tool
    • Technical plan for PIP support

2018 Q4

  • Technical plan for better support of WORKSPACE.configured (tentative)
  • Technical plan for improvements of repository rule APIs and semantics (no restarts? action graphs?)