Creating a JGit release and deploying it to Maven Central

Prerequisites

you need to be a Eclipse JGit committer
install jreleaser CLI
install python 3.12
install pipenv we use below to setup a python virtualenv
we sign release tags and Maven artifacts using GPG. Follow Git Tools - Signing Your Work to set this up on your computer before creating the first release.

register a user account on the Maven Central Portal
ask Eclipse Foundation to get yourself registered for the Maven Central namespace org.eclipse.jgit
login to the Maven Central Portal
if you don't already have one create a user token here

add the username and token from the user token to ~/.jreleaser/config.toml

JRELEASER_GITHUB_TOKEN="EMPTY"
JRELEASER_MAVENCENTRAL_TOKEN="maven central token"
JRELEASER_MAVENCENTRAL_USERNAME="maven central username"

store your gpg passphrase used for GPG signing the Maven artifacts in ~/.gnupg/passphrase
restrict read access to the jreleaser config and the gpg passphrase file to yourself
```
chmod 600 ~/.jreleaser/config.toml
chmod 600 ~/.gnupg/passphrase
```

Use the tools/release.sh script to create a new release, e.g.
```
./tools/release.sh v6.1.0.202203080745-r
```
this script
- modifies all version identifiers in pom.xml files and OSGi manifests to the new release version
- creates a commit
- tags the release commit using a signed, annotated tag
release versions have 5 parts major.minor.patch.buildTimestamp-qualifier
since 6.8 we use UTC timezone for the buildTimestamp part of the version number, earlier we used EST.
qualifier is m1, m2, ..., for milestones, rc1, rc2, ... for release candidates and r for releases
we create all milestones and releases on a dedicated stable branch to avoid interference with ongoing development on master. E.g. use the stable-6.1 branch for releasing 6.1.0 and subsequent patch releases like 6.1.1.
push the locally created release commit to eclipse.gerrithub.io for review
wait for the verification build to succeed until it votes +1 on the Verified label
review and submit the release change, then push the release tag to eclipse.gerrithub.io
```
$ git push origin tag v6.1.0.202203080745-r
```
the CI job will build the release version and deploy it to the Eclipse Maven Repository

prepare virtualenv for download_release.py:

$ cd tools/maven-central
$ pipenv --python 3.12
$ pipenv sync

download a JGit release from repo.eclipse.org and create artifact signature files (.asc) using your GPG signing key
```
$ pipenv run ./download_release.py 6.1.0.202203080745-r
```

deploy the release to maven central portal

$ JRELEASER_MAVENCENTRAL_STAGE=UPLOAD jreleaser deploy

check in the Maven Central Portal if the release looks good. You can download uploaded artifacts from there. How to manually test a staged release is explained here
publish the new release
- by clicking “Publish” on the portal deployment page
- or by running
```
$ JRELEASER_MAVENCENTRAL_STAGE=PUBLISH jreleaser deploy
```