Pulp

# Maven Plugin

I think this should actually be a maven plugin, since it needs to download both jar files and pom files which are maven artifacts. With each, there is a sha and md5 signature.

uniqueness : group_id + artifact_id + version (maybe, the hash???)  

types per unit : 1 pom, many jars. 2 sigs per item  

attriubtes : updated date (datetime)

clients: maven  

maybe https://pypi.python.org/pypi/jip

### Content

  - Root discovery uses the architype-catalog.xml file  

    https://maven.repository.redhat.com/ga/archetype-catalog.xml

  - Each archtype has a version metadata  

    https://maven.repository.redhat.com/ga/org/apache/ant/ant/maven-metadata.xml

### Discovery

  - It may be nice to have pulling down deps.

  - If not, you mirror everything

  - Or pull down a single item

# Notes from https://pulp.plan.io/issues/854

Create an initial framework for supporting syncing & publishing [Maven](https://maven.apache.org/what-is-maven.html) artifacts from within Pulp. This issue is an ok place for planning and gathering comments and information, but that should be broken up into smaller stories if/when implemented.

## Deliverables

  - A plugin module for maven artifacts

      - The plugin supports creating maven repositories

      - As a user, I can provide a URL, and possibly some additional information about how to discover specific content, that Pulp will use to sync a remote repository.

      - The plugin supports deleting maven repositories

      - As a user syncing from a remote Pulp, I only need to provide a URL to sync. Additional information about how to discover content should not be necessary.

      - The plugin supports uploading of maven modules to a repository

      - The plugin DOES NOT support lazy loading or syncing content from maven central

  - CLI support for creating maven repositories

  - CLI support for deleting maven repositories

  - CLI support for uploading a maven artifact

  - CLI support for deleting a maven artifact

## Questions

### archetype-catalog.xml

Some maven repositories appear to have an index of content named [archetype-catalog.xml](https://repository.jboss.org/nexus/content/repositories/releases/archetype-catalog.xml), and some [do not](http://jcenter.bintray.com/). What are the expectations around that file? When is/should it be present?

When Pulp does a sync, if that catalog is not present, we will need some other way for a user to specify what content to get. Should they provide a pom.xml file to the importer? Or perhaps csv/json that enumerates the content to get?

When Pulp does a publish, is it always safe for it to create an archetype-catalog.xml file? It is handy to have so that other Pulp deployments can sync from it and duplicate the exact same content.

### SNAPSHOT

Should Pulp support "snapshot" repositories?

https://blog.packagecloud.io/eng/2017/03/09/how-does-a-maven-repository-work/#snapshot-repositories

The challenge is that the content with a given unique identifier that includes "-SNAPSHOT" can change from one sync to the next, and there's no way to know if it did. So it would need to be downloaded every time. We would also have to accept that if the content had been promoted into an additional repository, it could get updated in-place without another promote operation.

### Upload

Is there a use case for upload? What does that look like? In what format would data get uploaded?

## References

  - https://blog.packagecloud.io/eng/2017/03/09/how-does-a-maven-repository-work/

## Repo in the sky

It may be worth looking at http://artificer.jboss.org/ just to see if there's any opportunity to integrate with that.