[MNG-6691] Maven protocol specification

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dzikoysk opened MNG-6691 and commented

There is a lot of guides and docs about "How to start" on maven.apache.org with maven as developer who wants to use maven in a project, but I'm not able to find something for people working with repository managers. Is there any technical specification of maven http/protocol specification/rest api and what's required from a custom repository manager to serve requests properly or the only way is to search in maven/other repositories like nexus, artifcatory sources?

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0 votes, 5 watchers

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Michael Osipov commented

Why do you need this? Do you plan to implement a repo manager?

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dzikoysk commented

Michael Osipov that's right. The first implementation (PoC that evolved into small repository manager) was just based on reverse engineering and it works, but it's also problematic to maintain. We don't really know how well we imitate the protocol, sometimes we're discovering a new issues (e.g. required handling of HEAD requests for some callers).

Now, we want to create full application and we are looking for any specification. It's strange that one of the most popular tool does not provide specification (or we can't find it). Honestly, even simple list with all procedures and expected order of request would be great.

[jira-importer]

Michael Osipov commented

Robert Scholte, I guess we don't have a formal specification, do we? Structures, XML formats, etc?

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Robert Scholte commented

This all happened before I joined the team. Tamas Cservenak might have something to share.

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Tamas Cservenak commented

Well, in my opinion, best doco is source, and it is up there. You can start by looking into Maven Wagon for start (ie. what it does, when issues HEAD, when GET, what it does with HTTP 429 response etc.). But frankly, am really unsure that you really want yet another Maven repo manager out there, unless you have some very good reasons to do so.

Am not aware of any spec, moreover, as maven transport is pluggable (multiple wagons can implement HTTP, but there is also takari okhttp transport, etc), and Aether by itself has transport, so IMO there is so broad area to doco on Maven side, nearly impossible.

On the other hand, you have very good starting point: something like Jetty default servlet (or resource handler) for example, as if you use it to "host" artifacts, it will "just work". So, what am implying, is that if you go MRM route, you basically need a full HTTP support, and you will not mistake. As I said, different wagons, aether transport etc may behave wildly different, so you have no "one target" to implement. Or to reverse, implement HTTP is your best bet.

[jira-importer]

dzikoysk commented

Yeah, it's what we need to do now and it's why I'm loking for something better. At this moment, we have only 3 open source repository managers where 2 of them are just trimmed-down versions of pro (commercial) software that is huge and heavy - honestly, I don't think that yet another phrase just fits here. Also, in our case it's not just Maven support, we're also targeting our language and related stuff, nvm, but it is not an option. It looks like there is no other resources than sources and we have to stay with our present methods. Thanks for your answers, just consider simple specification for future users :)

[jira-importer]

Hervé Boutemy commented

don't hesitate to contribute back your findings