Setup and implement publishing Maven artefacts to MavenCentral and OSSRH

[paullatzelsperger]

WHAT

In order to have tractusx-edc consumable also on code-level we need to publish all artefacts to MavenCentral. In Eclipse projects that happens through an EF-managed Jenkins instance ("JIPP") that contains signing keys for MavenCentral.

WHY

MavenCentral requires all artefacts to be signed. That is done in Jenkins.

Implementation proposal

• remove the publishAllPublicationsToGithubPackagesRepository task
• GH Actions triggers Jenkins (through this action)
• on releases: the version parameter does not contain the -SNAPSHOT suffix, thus causing it to sync to MavenCentral
• use the credentials provided by this EF helpdesk ticket to sign the artefacts, and to publish to OSSRH/MavenCentral.
• No Jenkins instance is required, we can directly push to OSSRH!
• comment on this OSSRH issue once our first release is published successfully.

OPEN QUESTIONS

• what's our publishing schedule? Snapshots on every push to develop? Nightlies?
• do we already have a publishing environment set up?
• if not: who will open helpdesk issues with EF and OSSRH? -> done here
• should we host the declarative pipelines in a GitHub repo? (in EDC we do that)

[edit]: updated description based on not having to use Jenkins.

[paullatzelsperger]

We are allowed to publish to MV directly from GH Actions, without going through Jenkins. Once this EF helpdesk issue is resolved, we can modify our publish workflow