Basic release tool for a Java 8 package including a push to Maven Central

Published here: https://hub.docker.com/r/robertbaboi/basic-java8-release

The purpose of this container is to perform a "Release" of a Java 8 package built with Maven and push it to Maven Central.

Env Variable	Default value	Required	Comments
DEPLOY	yes		To skip mvn deploy just override this with anything other than yes
RELEASE_TYPE	PATCH		Must be PATCH, MINOR or MAJOR (case insensitive)
GITHUB_REPO		YES
GITHUB_BRANCH	master
GITHUB_USERNAME		YES
GITHUB_EMAIL		YES
GITHUB_TOKEN_FILE	/work/secrets/github_token
SIGNING_KEY_FILE	/work/secrets/signingkey.asc
GPG_KEY_NAME_FILE	/work/secrets/gpg_keyname
GPG_KEY_PASSPHRASE_FILE	/work/secrets/gpg_key_passphrase
SONATYPE_USERNAME_FILE	/work/secrets/sonatype_username
SONATYPE_PASSWORD_FILE	/work/secrets/sonatype_password

Example

• The .m2 volume is mounted to avoid downloading the dependencies every time
• All the secrets are mounted into /work/secrets

docker run \
   -e GITHUB_REPO=github.com/${github_username}/${repo}.git \
   -e GITHUB_USERNAME=${github_username} \
   -e GITHUB_EMAIL=${github_email} \
   -v $(pwd)/../secrets:/work/secrets \
   -v $(pwd)/.m2:/root/.m2 \
  robertbaboi/basic-java8-release

What does it do

1. Checkout the branch
2. Identify the release version(${release_version}) from pom.xml and calculate the next version(${next_version}) using the RELEASE_TYPE env var
   • it uses a simplified semantic versioning system:
     • the version must match this regular expression: ^([0-9]+)\.([0-9]+)\.([0-9]+)\-SNAPSHOT$
   • The calculus will increase the version part to which the env var refers to
     • For example, for version 2.5.1-SNAPSHOT, for all possible types, the next version will be:
       • RELEASE_TYPE=PATCH: 2.5.2
       • RELEASE_TYPE=MINOR: 2.6.0
       • RELEASE_TYPE=MAJOR: 3.0.0
3. Switch to a new branch named RELEASE_${RELEASE_TYPE}_${release_version}
4. Change version to the ${release_version}
5. Build
6. Deploy
   • runs:

     mvn clean deploy \
       -DskipTests=true \
       -Prelease \
       --settings /work/settings.xml \
       -Dgpg.executable=gpg2 \
       -Dgpg.keyname=${gpg_keyname} \
       -Dgpg.passphrase=${gpg_key_passphrase}

   • as long as pom.xml is properly configured this will push to Maven Central
   • notice that this command activates the release profile
7. Commit the version change
8. Tags with v${release_version}
9. Updates the RELEASE_LOG.md file with a list of all commits in between this tag and the previous tag and commit
   • This is somewhat fragile because any other tags other than release tags will dirty this
10. Change the version to ${next_version} and commit
11. Push the release branch
12. Push the tag

Source Project Maven configuration

SCM Section (replace the <<...>> placeholders)

<scm>
    <connection>scm:git:https://github.com/<<username>>/<<repo>>.git</connection>
    <developerConnection>scm:git:ssh://github.com/<<username>>/<<repo>>.git</developerConnection>
    <url>https://github.com/<<username>>/<<repo>></url>
    <tag>HEAD</tag>
</scm>

Distribution Management Section

<distributionManagement>
   <snapshotRepository>
       <id>ossrh</id>
       <url>https://oss.sonatype.org/content/repositories/snapshots</url>
   </snapshotRepository>
   <repository>
       <id>ossrh</id>
       <url>https://oss.sonatype.org/service/local/staging/deploy/maven2</url>
   </repository>
</distributionManagement>

The release build profile

<profile>     

   <id>release</id>

   <build>

       <plugins>

           <plugin>
               <groupId>org.apache.maven.plugins</groupId>
               <artifactId>maven-javadoc-plugin</artifactId>
               <version>3.0.0</version>
               <executions>
                   <execution>
                       <id>attach-javadocs</id>
                       <goals>
                           <goal>jar</goal>
                       </goals>
                   </execution>
               </executions>
           </plugin>

           <plugin>
               <groupId>org.apache.maven.plugins</groupId>
               <artifactId>maven-source-plugin</artifactId>
               <version>3.2.0</version>
               <executions>
                   <execution>
                       <id>attach-sources</id>
                       <goals>
                           <goal>jar</goal>
                       </goals>
                   </execution>
               </executions>
           </plugin>

           <plugin>
               <groupId>org.apache.maven.plugins</groupId>
               <artifactId>maven-gpg-plugin</artifactId>
               <version>1.6</version>
               <executions>
                   <execution>
                       <id>sign-artifacts</id>
                       <phase>verify</phase>
                       <goals>
                           <goal>sign</goal>
                       </goals>
                       <configuration>
                           <gpgArguments>
                               <arg>--pinentry-mode</arg>
                               <arg>loopback</arg>
                           </gpgArguments>
                       </configuration>
                   </execution>
               </executions>
           </plugin>

           <plugin>
               <groupId>org.sonatype.plugins</groupId>
               <artifactId>nexus-staging-maven-plugin</artifactId>
               <version>1.6.8</version>
               <extensions>true</extensions>
               <configuration>
                   <serverId>ossrh</serverId>
                   <nexusUrl>https://oss.sonatype.org/</nexusUrl>
                   <autoReleaseAfterClose>true</autoReleaseAfterClose>
               </configuration>
           </plugin>

       </plugins>

   </build> 

</profile>