Emmanuel Lecharny wrote:
Hi Stefano !
Stefano Bagnara a écrit :
Emmanuel Lecharny wrote:
So, now, we have some points we need to discuss :
- the need of a local repo, where all the jars are stored, and
versionned, seems to me mandatory
I think that you don't need versioning when using maven repositories.
Maven repository expect that each new version of a jar get a new name
and you never override it (it caches artifacts by they version).
Imho you just need a repository, you don't need a versioned repository.
You should also make sure that you always use specific version in
"dependency/version" and never use an open range.
This is an assertion that does not resist to facts. If anyone just
change a pom.xml file just because there were something wrong ( and
regarding the number of jars in a full maven repo, and all the
dependencies any jars have ), this is more than likely to occurs. Let
say this will occur (and it has already occured). At least, the pom.xml
and .sha1 related with any jars should be versionned, but then to
guarantee that the jar remains available, then the jar itslef should be
versionned.
I think that if you start having different versioned artifact for each
version you will have much problems with Maven2. Imo you should try to
avoid this at all costs. Btw I'm not a maven expert.. just used it in a
few projects.
The pom is part of the artifact, if you change it you HAVE to make a new
release and create a new version for it.
I know this seems to me a little bit extermist, but at the end, this is
the way to go. And considering that jars are not changing very often, a
versionned repo seems just common sense to me. For the sake of reliable
builds.
Well, "versioned" is an additional option: imho it is not needed and you
should avoid to use versioning for artifacts, but the fact that you have
them in a versionable file system is not a problem :-)
[..]
Feel free to express what you think, and it can be as radical as
"Let's move to ant + ivy". I think that some decision will lead to a
vote at some point.
wdyt ?
What do you think that ivy repository will fix from maven2 repository?
Nothing at all. It's just totell people who may want to switch to ant :
"guys, it's ant PLUS ivy, not ant alone". The problem here is not maven
against ant, it's more or less the way we should manage this project.
But if we found 10 people wanting to help building a reliable build
system that want to switch to ant+ivy and only a couple of maven
afficionados, then there is a clear balance for ant+ivy. The problem we
have is more or less competence. I'm definitively not a maven or ant
guru, and we really are loosing a lot of time fixing those build issues,
and it's occuring too often. So just consider this mail as a SOS, not a
rant against maven.
This make sense. If you have skilled people on ivy then it worth working
with it. I've used both, but I'm not an expert. I feel maven2 (2!) is
already better and its architecture allow for much more improvements via
plugins. I would flee on another planet if you asked me to build
directory using ant+ivy: you have a lot of modules and a complex
dependency tree!
If you need the ant way to do thing, you can store the jar in the lib
folder and declare the dependency scope as "system" so maven2 does not
use the repository but read the jar from the folder you specified.
Thanks for the trick ! Do you have any pointer to documentation about
this feature ?
I used this in past:
<scope>system</scope>
<systemPath>${basedir}/lib/mydependency.jar</systemPath>
http://maven.apache.org/guides/introduction/introduction-to-dependency-mechanism.html
Unfortunately currently the site generation (dependency.html generation)
throw an NPE if you have system scoped libraries.
Btw I think that repositories are really cool and having a repository
for that libraries is better than having them in the source repository.
[...]
PS: As far as I know, I see that James project is using a /lib directory
to store all the jars it uses, so I assume that it is somehow related to
the issue we currently try to address. And I don't think that the James
project has done the wrong choice, IMHO :)
Please note that James Server currently use ANT as a build system. I
introduced a pom.xml only to generate the new james project website and
that pom.xml takes almost "random" dependency to be able to run tests
and create reports but is not intended as a build system for James
Server (Note to myself: I should add a disclaimer somewhere to make this
clear).
So we have jars in lib because we use basic ant ;-)
I've replied to this message because we (James PMC) are currently
discussing of maven2 and repository problems, similar to what you rised
here, and I think that we all (ASF projects) have similar requisites and
problems and we can discuss this things together.
As an example we evaluated the idea to create a maven2 repository for
james project and store there everything needed to build/run james
products. I currenlty have put some third party artifact in a temporary
repository while we search for a solution to this issue.
I'm reading the archives of [email protected] ml and I saw that
there is ongoing discussion about an ASF repository (already created)
and a new third party library repository (currently discussed).
I think that the solutions proposed for the ASF release/snapshot
repositories are good but I cannot see a solution for third party
libraries yet: I hope they will decide soon to create a third-party
libraries repository. I think that we can try to have a single
repository for all the ASF projects (I hope we can keep a cleaner
repository than ibiblio) and the maven2 repository structure make sense
even for non-maven users (I think).
I believe that maven2 is the way, and being it an ASF project we should
find collaboration from them to provide us the features we need.
I really like your "offline by default" and "interactive update"
suggestions. I think that maven2 developers will be happy to address our
problems: if we (other apache projects) leave maven in favor of another
build system they really failed their goal (IMO).
I also think that maven architecture and its plugin system should allow
us to create an "ASF release plugin" that simplify the creation/upload
of artifacts with md5/sha/pgp hashes/signatures.
That said my holidays are near now.. I'll look forward for your progress
at the end of august. Currenlty I think the best way is to create a
custom maven2 repository for each apache project (coordination need too
much time, now) and put there plugins and third party products needed to
build so that you have a "source repository" and an "artifact
repository", then we can try to merge to a single ASF repository for
third party artifacts. Btw I'm not strong with this idea.. I hope that
something better will be proposed here or on [EMAIL PROTECTED]
Stefano
