# How to Release to Maven Central, in One Click

Source: https://www.yegor256.com/2014/08/19/how-to-release-to-maven-central.html

When I release a new version of [jcabi-aspects](https://aspects.jcabi.com),
a Java open source library, to Maven Central, it takes 30 seconds of my time.
Maybe even less. Recently, I released version 0.17.2. You can see
how it all happened, in [GitHub issue #80](https://github.com/jcabi/jcabi-aspects/issues/80):

{% figure /images/2014/08/github-ticket-80.jpg 600 %}

As you see, I gave a command to [Rultor](https://www.rultor.com),
and it released a new version to Maven central. I didn't do anything else.

Now let's see how you can do the same. How you can configure your project
so that the release of its new version to Maven Central
takes just a few seconds of your time.


By the way, I assume that you're hosting your project in GitHub. If not,
this entire tutorial won't work. If you are still not in GitHub, I would
strongly recommend moving there.

## Prepare Your POM

{% youtube rEK3Rk2lX3M %}

Make sure your `pom.xml` contains all elements required by Sonatype,
explained in [Central Sync Requirements](http://central.sonatype.org/pages/requirements.html).
We will deploy to Sonatype, and they will synchronize all JAR (and not only)
artifacts to Maven Central.

## Register a Project With Sonatype

Create an account in [Sonatype JIRA](https://issues.sonatype.org/)
and raise a ticket, asking to approve your `groupId`. This
[OSSRH Guide](http://central.sonatype.org/pages/ossrh-guide.html)
explains this step in more detail.

## Create and Distribute a GPG Key

Create a GPG key and distribute it, as explained in this
[Working with PGP Signatures](http://central.sonatype.org/pages/working-with-pgp-signatures.html)
article.

When this step is done, you should have two files:
`pubring.gpg` and `secring.gpg`.

## Create settings.xml

Create `settings.xml`, next to the two `.gpg` files created in the previous step:

```xml
<settings>
  <profiles>
    <profile>
      <id>foo</id> <!-- give it the name of your project -->
      <properties>
        <gpg.homedir>/home/r</gpg.homedir>
        <gpg.keyname>9A105525</gpg.keyname>
        <gpg.passphrase>my-secret</gpg.passphrase>
      </properties>
    </profile>
  </profiles>
  <servers>
    <server>
      <id>oss.sonatype.org</id>
      <username><!-- Sonatype JIRA user name --></username>
      <password><!-- Sonatype JIRA pwd --></password>
    </server>
  </servers>
</settings>
```

In this example, `9A105525` is the ID of your public key, and `my-secret`
is the pass phrase you have used while generating the keys.

## Encrypt Security Assets

Now, encrypt these three files with a [rultor remote](https://github.com/yegor256/rultor-remote):

```xml
$ gem install rultor
$ rultor encrypt -p me/test pubring.gpg
$ rultor encrypt -p me/test secring.gpg
$ rultor encrypt -p me/test settings.xml
```

Instead of `me/test` you should use the name of your GitHub project.

You will get three new files: `pubring.gpg.asc`, `secring.gpg.asc`
and `settings.xml.asc`. Add them to the root directory of your project,
commit and push. The files contain your secret information,
but only the Rultor server can decrypt them.

## Add Sonatype Repositories

I would recommend using [jcabi-parent]({% pst 2015/feb/2015-02-05-jcabi-parent-maven-pom %}), as
a parent pom for your project. This will make many further steps
unnecessary. If you're using jcabi-parent, skip this step.

However, if you don't use jcabi-parent, you should add these two repositories
to your `pom.xml`:

```xml
<project>
  [...]
  <distributionManagement>
    <repository>
      <id>oss.sonatype.org</id>
      <url>https://oss.sonatype.org/service/local/staging/deploy/maven2/</url>
    </repository>
    <snapshotRepository>
      <id>oss.sonatype.org</id>
      <url>https://oss.sonatype.org/content/repositories/snapshots</url>
    </snapshotRepository>
  </distributionManagement>
</project>
```

## Configure GPG Plugin

Again, I'd recommend using [jcabi-parent](https://parent.jcabi.com),
which configures this plugin automatically. If you're using it, skip this step.

Otherwise, add this plugin to your `pom.xml`:

```xml
<project>
  [..]
  <build>
    [..]
    <plugins>
      [..]
      <plugin>
        <artifactId>maven-gpg-plugin</artifactId>
        <version>1.5</version>
        <executions>
          <execution>
            <id>sign-artifacts</id>
            <phase>verify</phase>
            <goals>
              <goal>sign</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
</project>
```

## Configure Versions Plugin

Once again, I recommend using [https://parent.jcabi.com]({% pst 2015/feb/2015-02-05-jcabi-parent-maven-pom %}). It
configures all required plugins out-of-the-box. If you're using it, skip this step.

Otherwise, add this plugin to your `pom.xml`:

```xml
<project>
  [..]
  <build>
    [..]
    <plugins>
      [..]
      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>versions-maven-plugin</artifactId>
        <version>2.1</version>
        <configuration>
          <generateBackupPoms>false</generateBackupPoms>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>
```

## Configure Sonatype Plugin

Yes, you're right, [https://parent.jcabi.com]({% pst 2015/feb/2015-02-05-jcabi-parent-maven-pom %}) will help
you here as well. If you're using it, skip this step too.

Otherwise, add these four plugins to your `pom.xml`:

```xml
<project>
  [..]
  <build>
    [..]
    <plugins>
      [..]
      <plugin>
        <artifactId>maven-deploy-plugin</artifactId>
        <configuration>
          <skip>true</skip>
        </configuration>
      </plugin>
      <plugin>
        <artifactId>maven-source-plugin</artifactId>
        <executions>
          <execution>
            <id>package-sources</id>
            <goals>
              <goal>jar</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
      <plugin>
        <artifactId>maven-javadoc-plugin</artifactId>
        <executions>
          <execution>
            <id>package-javadoc</id>
            <phase>package</phase>
            <goals>
              <goal>jar</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
      <plugin>
        <groupId>org.sonatype.plugins</groupId>
        <artifactId>nexus-staging-maven-plugin</artifactId>
        <version>1.6</version>
        <extensions>true</extensions>
        <configuration>
          <serverId>oss.sonatype.org</serverId>
          <nexusUrl>https://oss.sonatype.org/</nexusUrl>
          <description>${project.version}</description>
        </configuration>
        <executions>
          <execution>
            <id>deploy-to-sonatype</id>
            <phase>deploy</phase>
            <goals>
              <goal>deploy</goal>
              <goal>release</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
</project>
```

## Create Rultor Configuration

Create a `.rultor.yml` file in the root directory of your project
([reference page](https://doc.rultor.com/reference.html)
explains this format in details):

```text
decrypt:
  settings.xml: "repo/settings.xml.asc"
  pubring.gpg: "repo/pubring.gpg.asc"
  secring.gpg: "repo/secring.gpg.asc"
release:
  script: |
    mvn -ntp versions:set "-DnewVersion=${tag}"
    git commit -am "${tag}"
    mvn clean deploy -Pjcabi --settings /home/r/settings.xml
```

You can compare your file with live Rultor
[configuration of jcabi-aspects](https://github.com/jcabi/jcabi-aspects/blob/master/.rultor.yml).

## Run It!

{% badge https://doc.rultor.com/images/logo.svg M https://www.rultor.com %}

Now it's time to see how it all works. Create a new ticket in the
GitHub issue tracker, and post something like that into it
(read more about [Rultor commands](https://doc.rultor.com/basics.html)):

```text
@rultor release, tag is `0.1`
```

You will get a response in a few seconds. The rest will be done by Rultor.

Enjoy!

BTW, if something doesn't work as I've explained, don't hesitate to
submit a ticket to
[Rultor issue tracker](https://github.com/yegor256/rultor/issues).
I will try to help you.

Yeah, forgot to mention, Rultor is also doing two important things. First,
it creates a GitHub release with a proper description. Second, it
posts a tweet about the release, which you can retweet, to make
an announcement to your followers. Both features are very convenient
for me. For example:

<blockquote class="twitter-tweet" lang="en"><p>DynamoDB Local Maven Plugin, 0.7.1 released <a href="https://t.co/C3KULouuKS">https://t.co/C3KULouuKS</a></p>---rultor.com (@rultors) <a href="https://twitter.com/rultors/statuses/501617747269517312">August 19, 2014</a></blockquote>
<script async='' src="http://platform.twitter.com/widgets.js" charset="utf-8"></script>