Here I’m going to walk through the real life example of the process for publishing an open source library in Maven Central.

When I tried to figure out how to do that first time I couldn’t find one source that contains all related aspects. I had to spent a lot of time on that and made many mistakes.

This is an attempt to collect all findings in one place.

Since this is going to be a huge topic I’ll keep it as a live document with many updates. We all can make mistakes, miss something and be wrong. So please correct me if you find something wrong/missing here. Thanks!

I’m assuming that you already have your project/library somewhere in GitHub and you already have selected the license for your library.

That’s the plan:

  • Create a virtual machine where you can setup everything you need
  • Create a Sonatype OSS account
  • Create a ticket
  • Pick up a right groupId
  • Prepare pom.xml
  • Prepare Maven settings.xml
  • Generate gpg key
  • Maven deploy and release commands

Create and configure Virtual Machine

I prefer using VirtualBox and Ubuntu for that but it’s up to you.

Once you’re done with creating a Virtual Machine you need to

  • Install and configure Git
  • Clone your library repository
  • Install Java
  • Install and configure Maven

We will need to do extra configurations for Maven later

Create Sonatype OSS account

Create an account in Sonatype OSS Repository Hosting Service JIRA - http://issues.sonatype.org/.

That service allows you to publish your library to Maven Central.

Once it’s created create a ticket here https://issues.sonatype.org/projects/OSSRH

IssueType: New Project

Summary, Description: Briefly describe what your library is about. Literally one sentence for each.

Group Id: It should be the domain that you own, I personally use io.lenar. That allows me to publish more than one library without having to create additional tickets, for example io.lenar:easy-log and io.lenar:app-props.

Project url: My example - https://github.com/LenarBad/app-props

SCM url: My example - https://github.com/LenarBad/app-props.git

Prepare pom.xml

Initially when you write your code for a Maven project your pom.xml looks pretty compact but when you go to oprn source it becomes huge.

For example the pom.xml file of one of my projects io.lenar:app-props at the start point was about 15-20 lines - only the info that is required - groupId, artifactId, version and a couple of dependencies.

When I decided to go open source it turned into this

10 times bigger.

Prepare Maven settings.xml

Replace your-sonatype-username, your-sonatype-password, your-github-email, github-password and your-gpg-passphrase with your values.

Generate pgp key

First install GnuPG

sudo apt-get install gnupg

Then generate a key

gpg --gen-key

Set required parameters RSA and RSA/2048/Expiration - Never/Name/Email/passphrase

Verify that you successfuly created a key

gpg --list-keys

You should have something like this

pub   2048R/123ABCDF 2019-04-20 [expires: 2020-10-11]
uid                  John Smith <john.smith@g-hot-web-mail.com>
sub   2048R/456FDCBA 2019-04-20 [expires: 2020-10-11]

Then you have to upload your key

gpg --keyserver hkp://pool.sks-keyservers.net --send-keys 123ABCDF

Publish to Maven Central

To release your library you should execute 3 maven commands

mvn deploy

mvn release:prepare

mvn release:perform

If you did everything right then you can use your library as a dependency in any Maven/Gradle project

Mission complete…

Next time when you need to publish another project to Maven Central with Sonatype OSS just configure you pom.xml and publish with Maven deploy and release commands.

PS: Please feel free to fingerpoint at any mistakes you notice and suggest improvements that need to be done