How to Create a Release of GRPC Java (for Maintainers Only)

Build Environments

We deploy GRPC to Maven Central under the following systems:

  • Ubuntu 14.04 with Docker 1.6.1 that runs CentOS 6.6
  • Windows 7 64-bit with MSYS2 with mingw32 and mingw64
  • Mac OS X 10.9.5

Other systems may also work, but we haven't verified them.

Prerequisites

Setup OSSRH and Signing

If you haven't deployed artifacts to Maven Central before, you need to setup your OSSRH (OSS Repository Hosting) account and signing keys.

  • Follow the instructions on this page to set up an account with OSSRH.
    • You only need to create the account, not set up a new project
    • Contact a gRPC maintainer to add your account after you have created it.
  • (For release deployment only) Install GnuPG and generate your key pair. You'll also need to publish your public key to make it visible to the Sonatype servers (e.g. gpg --keyserver pgp.mit.edu --send-key <key ID>).
  • Put your GnuPG key password and OSSRH account information in <your-home-directory>/.gradle/gradle.properties.
# You need the signing properties only if you are making release deployment
signing.keyId=<8-character-public-key-id>
signing.password=<key-password>
signing.secretKeyRingFile=<your-home-directory>/.gnupg/secring.gpg

ossrhUsername=<ossrh-username>
ossrhPassword=<ossrh-password>
checkstyle.ignoreFailures=false

Build Protobuf

Protobuf libraries are needed for compiling the GRPC codegen. Despite that you may have installed Protobuf on your system, you may want to build Protobuf separately and install it under your personal directory, because

  1. The Protobuf version installed on your system may be different from what GRPC requires. You may not want to pollute your system installation.
  2. We will deploy both 32-bit and 64-bit versions of the codegen, thus require both variants of Protobuf libraries. You don't want to mix them in your system paths.

Please see the Main Readme for details on building protobuf.

Tagging the Release

The first step in the release process is to create a release branch, bump versions, and create a tag for the release. Our release branches follow the naming convention of v<major>.<minor>.x, while the tags include the patch version v<major>.<minor>.<patch>. For example, the same branch v0.7.x would be used to create all v0.7 tags (e.g. v0.7.0, v0.7.1).

  1. Create the release branch and push it to GitHub:

    $ MAJOR=0 MINOR=7 PATCH=0 # Set appropriately for new release
    $ git checkout -b v$MAJOR.$MINOR.x master
    $ git push upstream v$MAJOR.$MINOR.x
    
  2. For master, change build.gradle and android-interop-testing/app/build.gradle to the next minor snapshot (e.g. 0.8.0-SNAPSHOT).

    $ git checkout -b bump-version master
    # Change version to next minor (and keep -SNAPSHOT)
    $ sed -i 's/[0-9]\+\.[0-9]\+\.[0-9]\+\(.*CURRENT_GRPC_VERSION\)/'$MAJOR.$((MINOR+1)).0'\1/' \
      build.gradle android-interop-testing/app/build.gradle
    $ git commit -a -m "Start $MAJOR.$((MINOR+1)).0 development cycle"
    
  3. Go through PR review and push the master branch to GitHub:

    $ git checkout master
    $ git merge --ff-only bump-version
    $ git push upstream master
    
  4. For vMajor.Minor.x branch, change build.gradle and android-interop-testing/app/build.gradle to remove "-SNAPSHOT" for the next release version (e.g. 0.7.0). Commit the result and make a tag:

    $ git checkout -b release v$MAJOR.$MINOR.x
    # Change version to remove -SNAPSHOT
    $ sed -i 's/-SNAPSHOT\(.*CURRENT_GRPC_VERSION\)/\1/' \
      build.gradle android-interop-testing/app/build.gradle
    $ git commit -a -m "Bump version to $MAJOR.$MINOR.$PATCH"
    $ git tag -a v$MAJOR.$MINOR.$PATCH -m "Version $MAJOR.$MINOR.$PATCH"
    
  5. Change build.gradle and android-interop-testing/app/build.gradle to the next snapshot version (e.g. 0.7.1-SNAPSHOT). Commit the result:

    # Change version to next patch and add -SNAPSHOT
    $ sed -i 's/[0-9]\+\.[0-9]\+\.[0-9]\+\(.*CURRENT_GRPC_VERSION\)/'$MAJOR.$MINOR.$((PATCH+1))-SNAPSHOT'\1/' \
      build.gradle android-interop-testing/app/build.gradle
    $ git commit -a -m "Bump version to $MAJOR.$MINOR.$((PATCH+1))-SNAPSHOT"
    
  6. Go through PR review and push the release tag and updated release branch to GitHub:

    $ git checkout v$MAJOR.$MINOR.x
    $ git merge --ff-only release
    $ git push upstream v$MAJOR.$MINOR.$PATCH
    $ git push upstream v$MAJOR.$MINOR.x
    

Setup Build Environment

Linux

The deployment for Linux uses Docker running CentOS 6.6 in order to ensure that we have a consistent deployment environment on Linux. You'll first need to install Docker if not already installed on your system. Make sure to have at least version 1.7.1 or later.

  1. Under the Protobuf source directory, build the protoc-artifacts image:

    protobuf$ docker build -t protoc-artifacts protoc-artifacts
    
  2. Under the grpc-java source directory, build the grpc-java-deploy image:

    grpc-java$ docker build -t grpc-java-deploy compiler
    
  3. Start a Docker container that has the deploy environment set up for you. The GRPC source is cloned into /grpc-java.

    $ docker run -it --rm=true grpc-java-deploy
    

    Note that the container will be deleted after you exit. Any changes you have made (e.g., copied configuration files) will be lost. If you want to keep the container, remove --rm=true from the command line.

  4. Next, you'll need to copy your OSSRH credentials and GnuPG keys to your docker container. In Docker:

    # mkdir /root/.gradle
    

    Find the container ID in your bash prompt, which is shown as [root@<container-ID> ...]. In host:

    $ docker cp ~/.gnupg <container-ID>:/root/
    $ docker cp ~/.gradle/gradle.properties <container-ID>:/root/.gradle/
    

    You'll also need to update signing.secretKeyRingFile in /root/.gradle/gradle.properties to point to /root/.gnupg/secring.gpg.

Windows

Windows 64-bit with MSYS2 (Recommended for Windows)

Because the gcc shipped with MSYS2 doesn't support multilib, you have to compile and deploy 32-bit and 64-bit binaries in separate steps.

Under MinGW-w64 Win32 Shell
  1. Compile and install 32-bit protobuf:

    protobuf$ ./configure --disable-shared --prefix=$HOME/protobuf-32
    protobuf$ make clean && make && make install
    
  2. Configure CXXFLAGS needed by the protoc plugin when building.

    grpc-java$ export CXXFLAGS="-I$HOME/protobuf-32/include" \
      LDFLAGS="-L$HOME/protobuf-32/lib"
    
Under MinGW-w64 Win64 Shell
  1. Compile and install 64-bit protobuf:

    protobuf$ ./configure --disable-shared --prefix=$HOME/protobuf-64
    protobuf$ make clean && make && make install
    
  2. Configure CXXFLAGS needed by the protoc plugin when building.

    grpc-java$ export CXXFLAGS="-I$HOME/protobuf-64/include" \
      LDFLAGS="-L$HOME/protobuf-64/lib"
    

Windows 64-bit with Cygwin64 (TODO: incomplete)

Because the MinGW gcc shipped with Cygwin64 doesn't support multilib, you have to compile and deploy 32-bit and 64-bit binaries in separate steps.

  1. Compile and install 32-bit protobuf. -static-libgcc -static-libstdc++ are needed for protoc to be successfully run in the unit test.

    protobuf$ LDFLAGS="-static-libgcc -static-libstdc++" ./configure --host=i686-w64-mingw32 --disable-shared --prefix=$HOME/protobuf-32
    protobuf$ make clean && make && make install
    
  2. Compile and install 64-bit protobuf:

    protobuf$ ./configure --host=x86_64-w64-mingw32 --disable-shared --prefix=$HOME/protobuf-64
    protobuf$ make clean && make && make install
    

Mac

Please refer to Protobuf README for how to set up GCC and Unix tools on Mac.

Mac OS X has been 64-bit-only since 10.7 and we are compiling for 10.7 and up. We only build 64-bit artifact for Mac.

  1. Compile and install protobuf:

    protobuf$ CXXFLAGS="-m64" ./configure --disable-shared --prefix=$HOME/protobuf
    protobuf$ make clean && make && make install
    
  2. Configure CXXFLAGS needed by the protoc plugin when building.

    grpc-java$ export CXXFLAGS="-I$HOME/protobuf/include" \
      LDFLAGS="$HOME/protobuf/lib/libprotobuf.a $HOME/protobuf/lib/libprotoc.a"
    

Build and Deploy

We currently distribute the following OSes and architectures:

OSx86_32x86_64
LinuxXX
WindowsXX
MacX

Deployment to Maven Central (or the snapshot repo) is a two-step process. The only artifact that is platform-specific is codegen, so we only need to deploy the other jars once. So the first deployment is for all of the artifacts from one of the selected OS/architectures. After that, we then deploy the codegen artifacts for the remaining OS/architectures.

NOTE: Before building/deploying, be sure to switch to the appropriate branch or tag in the grpc-java source directory.

First Deployment

As stated above, this only needs to be done once for one of the selected OS/architectures. The following command will build the whole project and upload it to Maven Central.

grpc-java$ ./gradlew clean build && ./gradlew uploadArchives

If the version has the -SNAPSHOT suffix, the artifacts will automatically go to the snapshot repository. Otherwise it's a release deployment and the artifacts will go to a freshly created staging repository.

Deploy GRPC Codegen for Additional Platforms

The previous step will only deploy the codegen artifacts for the OS you run on it and the architecture of your JVM. For a fully fledged deployment, you will need to deploy the codegen for all other supported OSes and architectures.

To deploy the codegen for an OS and architecture, you must run the following commands on that OS and specify the architecture by the flag -PtargetArch=<arch>.

If you are doing a snapshot deployment:

grpc-java$ ./gradlew clean grpc-compiler:build grpc-compiler:uploadArchives -PtargetArch=<arch>

When deploying a Release, the first deployment will create a new staging repository. You'll need to look up the ID in the OSSRH UI (usually in the form of iogrpc-*). Codegen deployment commands should include -PrepositoryId=<repository-id> in order to ensure that the artifacts are pushed to the same staging repository.

grpc-java$ ./gradlew clean grpc-compiler:build grpc-compiler:uploadArchives -PtargetArch=<arch> \
    -PrepositoryId=<repository-id>

Releasing on Maven Central

Once all of the artifacts have been pushed to the staging repository, the repository must first be closed, which will trigger several sanity checks on the repository. If this completes successfully, the repository can then be released, which will begin the process of pushing the new artifacts to Maven Central (the staging repository will be destroyed in the process). You can see the complete process for releasing to Maven Central on the [OSSRH site] (http://central.sonatype.org/pages/releasing-the-deployment.html).

Notify the Community

After waiting ~1 day and verifying that the release appears on [Maven Central] (http://mvnrepository.com/), the last step is to document and publicize the release.

  1. Add Release Notes for the new tag. The description should include any major fixes or features since the last release. You may choose to add links to bugs, PRs, or commits if appropriate.
  2. Post a release announcement to grpc-io (grpc-io@googlegroups.com). The title should be something that clearly identifies the release (e.g.GRPC-Java <tag> Released).

Update README.md

Update the version numbers in README.md to the new grpc-java version. Also update the version numbers for protoc if the protobuf library version was updated since last release. Make a new commit with description similar to "Update README to reference <VERSION>" and have it reviewed before submitting.

Update Hosted Javadoc

Now we need to update gh-pages with the new Javadoc:

git checkout gh-pages
rm -r javadoc/
wget -O grpc-all-javadoc.jar "http://search.maven.org/remotecontent?filepath=io/grpc/grpc-all/$MAJOR.$MINOR.$PATCH/grpc-all-$MAJOR.$MINOR.$PATCH-javadoc.jar"
unzip -d javadoc grpc-all-javadoc.jar
rm grpc-all-javadoc.jar
rm -r javadoc/META-INF/
git add -A javadoc
git commit -m "Javadoc for $MAJOR.$MINOR.$PATCH"

Push gh-pages to the main repository and verify the current version is live on grpc.io.