gRPC depends on several third-party libraries, their source code is available (usually as a git submodule) in this directory.
IMPORTANT: whenever possible, try to only update to a stable release of a library (= not to master / random commit). Depending on unreleased revisions makes gRPC installation harder for users, as it forces them to always build the dependency from source and prevents them from using more convenient installation channels (linux packages, package managers etc.)
bazel BUILD uses a different dependency model - whenever updating a submodule, also update the revision in grpc_deps.bzl
so that bazel and
non-bazel builds stay in sync (this is actually enforced by a sanity check in some cases)
gRPC C++ needs to stay buildable/installable even if the submodules are not present (e.g. the tar.gz archive with gRPC doesn't contain the submodules), assuming that the dependencies are already installed. This is a requirement for being able to provide a reasonable install process (e.g. using cmake) and to support package managers for gRPC C++.
Adding a new dependency is a lot of work (both for us and for the users). We currently support multiple build systems (BAZEL, cmake, make, ...) so adding a new dependency usually requires updates in multiple build systems (often not trivial). The installation process also needs to continue to work (we do have distrib tests to test many of the possible installation scenarios, but they are not perfect). Adding a new dependency also usually affects the installation instructions that need to be updated. Also keep in mind that adding a new dependency can be quite disruptive for the users and community - it means that all users will need to update their projects accordingly (for C++ projects often non-trivial) and the community-provided C++ packages (e.g. vcpkg) will need to be updated as well.
READ THIS BEFORE YOU ADD A NEW DEPENDENCY
[ ] Make sure you understand the hidden costs of adding a dependency (see section above) and that you understand the complexities of updating the build files. Maintenance of the build files isn't for free, so expect to be involved in maintenance tasks, cleanup and support (e.g resolving user bugs) of the build files in the future.
[ ] Once your change is ready, start an adhoc run of artifact - packages - distribtests flow and make sure everything passes (for technical reasons, not all the distribtests can run on each PR automatically).
[ ] Check the impact of the new dependency on the size of our distribution packages (compare BEFORE and AFTER) and post the comparison on your PR (it should not be approved without checking the impact sizes of packages first). The package sizes AFTER can be obtained from the adhoc package build from bullet point above.
Usually the process is
grpc_deps.bzl
to the same committools/run_tests/sanity/check_submodules.sh
to make the sanity test passtools/buildgen/generate_projects.sh
to regenerate the generated filesbazel/update_mirror.sh
Updating some dependencies requires extra care.
generate_projects.sh
above.
src/abseil-cpp/preprocessed_builds.yaml.gen.py
.abseil_version =
scripts in templates/gRPC-C++.podspec.template
and
templates/gRPC-Core.podspec.template
.NOTE: updating the boringssl dependency is now part of the internal grpc release tooling (see go/grpc-release). Prefer using the release tooling when possible. The instructions below are provided as a reference and aren't guaranteed to be up-to-date.
Update the third_party/boringssl-with-bazel
submodule to the latest master-with-bazel
branch
git submodule update --init # just to start in a clean state
cd third_party/boringssl-with-bazel
git fetch origin # fetch what's new in the boringssl repository
git checkout origin/master-with-bazel # checkout the current state of master-with-bazel branch in the boringssl repo
# Note the latest commit SHA on master-with-bazel branch
cd ../.. # go back to grpc repo root
git status # will show that there are new commits in third_party/boringssl-with-bazel
git add third_party/boringssl-with-bazel # we actually want to update the changes to the submodule
git commit -m "update submodule boringssl-with-bazel with origin/master-with-bazel" # commit
Update boringssl dependency in bazel/grpc_deps.bzl
to the same commit SHA as master-with-bazel branch
http_archive(name = "boringssl",
section by updating the sha in strip_prefix
and urls
fields.sha256
field to "" as the existing value is not valid. This will be added later once we know what that value is.Update tools/run_tests/sanity/check_submodules.sh
with the same commit
Commit these changes git commit -m "update boringssl dependency to master-with-bazel commit SHA"
Run tools/buildgen/generate_projects.sh
to regenerate the generated files
Because sha256
in bazel/grpc_deps.bzl
was left empty, you will get a DEBUG msg like this one:
Rule 'boringssl' indicated that a canonical reproducible form can be obtained by modifying arguments sha256 = "SHA value"
Commit the regenrated files git commit -m "regenerate files"
Update bazel/grpc_deps.bzl
with the SHA value shown in the above debug msg. Commit again git commit -m "Updated sha256"
Run tools/distrib/generate_boringssl_prefix_header.sh
git commit -m "generate boringssl prefix headers"
Increment the boringssl podspec version number in
templates/src/objective-c/BoringSSL-GRPC.podspec.template
and templates/gRPC-Core.podspec.template
.
example
git commit -m "Increment podspec version"
Run tools/buildgen/generate_projects.sh
(yes, again)
git commit -m "Second regeneration"
Create a PR with all the above commits.
Run bazel/update_mirror.sh
to update GCS mirror.
Updating the protobuf dependency is now part of the internal release process (see go/grpc-release).
Apart from the above steps, please perform the following two steps to generate the Python xds-protos
package:
tools/distrib/python/xds_protos/setup.py
;tools/distrib/python/xds_protos/build_validate_upload.sh
to upload the built wheel.Since upb is vendored in the gRPC repo, you cannot use submodule to update it. Please follow the steps below.
export GRPC_ROOT=~/git/grpc
wget https://github.com/protocolbuffers/upb/archive/refs/heads/main.zip
rm -rf $GRPC_ROOT/third_party/upb
unzip main.zip -d $GRPC_ROOT/third_party
mv $GRPC_ROOT/third_party/upb-main $GRPC_ROOT/third_party/upb
grpc_deps.bzl
to the same commitbazel/update_mirror.sh
src/upb/gen_build_yaml.py
for newly added or removed upb files
bazel query "deps(upb) union deps(json) union deps(textformat)"
under third_party/upb would give some idea on what needs to be included.tools/buildgen/generate_projects.sh
to regenerate the generated filestools/codegen/core/gen_upb_api.sh
to regenerate upb files.TODO(https://github.com/Cyan4973/xxHash/issues/548): revisit LICENSE instructions if upstream splits library and CLI.
The upstream xxhash repository contains a bunch of files that we don't want, so we employ a rather manual update flow to pick up just the bits we care about:
git remote add xxhash https://github.com/Cyan4973/xxHash.git
git fetch xxhash
git show xxhash/dev:xxhash.h > third_party/xxhash/xxhash.h
git show xxhash/dev:LICENSE | sed -nE '/^-+$/q;p' > third_party/xxhash/LICENSE