I have setup a multimodule project with maven.
hierachie is
- parent
-- module 1
-- module 2
-- module n
I am wondering, how I can release just one single module of this project in Jenkins.
Would appreciate any comments.
Thank you
No problem with that, go for the maven-release-plugin and release the modules of interest only.
You should start with the parent. Afterwards, go for the others (assuming inheritence is in place, and these are not submodules of parent). Moreover, as there might be dependencies between modules, make sure to follow the rule, that: there are no SNAPSHOT dependencies on the module you're about to release.
For deeper understanding, check the official docs of maven-release-plugin, or go for the link (that seems to summarize/detail steps on release, even the background things happening).
Steps to be done on each module are:
preparation for release
performing a release
Moreover, as you're interested in Jenkins release, you should go for: non-interactive release
Well, release plugin might be a pain to use properly/get used to, but once it's setup, moreover assuming Jenkins jobs would be created for the purpose, things should get settled and releases smooth.
Related
I have a number of builds that creates a package that is published to a package manager (for example NPM, Nuget and Maven).
I have subsequent builds that trigger on the completion of this build, they get the artifact from this repository. The problem is they show a warning:
I'm considering adding a Snapshot dependency, however, Teamcity's UI describes snapshot dependencies as builds using the same sources:
There is no source dependency between these projects and in fact, they may have completely different VCS roots.
What is the appropriate way to link these projects? Reading the documentation on Snapshot Dependencies, it sounds like things might not work as expected if I add a dependency without shared sources.
There is no requirement to link these projects, other than by the trigger you already have I don't think.
If the triggered build always gets the latest version from the package manager, then you'll get the behaviour that you want.
Snapshot dependency simply ensures that a build which depends on another build gets the same version of the source code when it builds, and doesn't end up being built using some changes that someone else checked in between the first build starting and the second build starting. This doesn't look like its going to be an issue in your situation (and indeed the builds may use completely different repositories), so I think your finished build trigger is an appropriate solution.
I was trying to build Maven pom in something similar to the following hierarchical form:
root
+-- A-POM
+-- B-POM
+-- C-POM
+---D-POM
I was hoping that this could take care of my changed module problem. That is, if C is changed, then A must be rebuilt, etc.
But I ran into the issue that it seems the packaging at root is "pom," and after that I can't have A as packaging "war" then continue to drill in to have A include B, C as its modules. It seems to me that any POM which does not have "pom" in the then it can't have child modules. Is my understanding correct? Is there a way to do what I wanted to do?
In addition, I don't seem about to chain the "changed" mechanism in Maven (must due to my lack of knowledge). I like to have Maven detect a dependent project has changed and rebuild all the affected projects.
Thanks so much!
the reactor project (the root of the multimodule project) must have pom packaging. So your nested structure is invalid since A is not of type pom and I'm pretty sure you won't get it to work this way.
Second point is that Maven is a modularized build system and uses repository mechanisms to locate pre-built artifacts instead of checking out all modules from version control and building them in a monolithic way like in the old days ;) This means that Maven cannot know what to rebuild when you change something at your module since it simple does not have all the other module there at this time.
I think this is more a CI task than that should be handled by the build system itself. I know that your can achieve such a behavior with an appropriate build/CI Server like Jenkins that supports upstream and downstream projects. This means it is able to detect dependencies between the projects and trigger other builds as soon as a dependency has been built. This comes close to the behavior you are trying to achieve.
Btw. rebuilding other projects is only required for SNAPSHOT dependencies. Jenkins with the maven plugin supports this behavior but, depending on the number of SNAPSHOT dependencies of your project, this can cause long chains of project builds on the server. Some folks are of the opinion that in general SNAPSHOT versions are hell for CI tasks since these artifacts can change over time and are not reproducible. You could think over completely omitting SNAPSHOT versions and building final versions each time. This would also obviate your requirement to rebuild other modules as soon as a module changes. There are simply no changes until you upgrade dependency versions.
This is probably supported, so I apologize if the answer is trivial, but I can't find an answer.
I have a multimodule (aggregate) pom containing a number of modules with interdependencies. Let's say something like:
infrastructure
framework
business-module1
business-module2
At a certain moment, infrastructure is stable, so I can release it. The version is updated to 1.0 and all dependencies to it are updated to that version as well.
When doing a local install, the module is still build. I know want to avoid building the 1.0 version locally, since it is released and costs build time. The question could be rephrased to, never build a released module.
I have quite a lot of modules in a multimodule setup, and only want to build snapshots. I know that I can skip modules using command line options, but don't want to repeat all these modules. Besides, from the version declarations, it should be clear to maven which modules to build.
I have two multi module projects. One is the main project tree. The other project tree pulls in the artifacts (WARs, JARs, etc) from the first project. They each have their own separate parent pom.
I would like to keep their version numbers identical. Project 2 has a dependency management section that has the artifacts from project 1 in it. The problem with this is that I can't release the project due to snapshots.
For example. The version number (for both projects) is 3.4-SNAPSHOT. I can release a version 3.4 of project 1 and all the pom versions will be set from 3.4-SNAPSHOT to 3.5. When I go into project 2, I want to do the same exact thing. The hitch is that dependencies of project 1 are at 3.4-SNAPSHOT and I can't figure out how to automatically get them to be 3.5. It's like I want the dependencies to be updated to the release version, before actually releasing.
I understand that if I make both trees extend from the same parent pom, the maven release plugin would detect the dependencies as submodules and update them automatically.
I read a little bit about the versions plugin but I didn't like the use-latest-versions part of it (it seems way to dangerous). The Update-properties seemed promising but it upon a second cursory look, it looked like the use-latest-versions plugin packaged slightly different.
Also, I tried just using ${project.version} but that's basically the same as putting 3.4-SNAPSHOT in as the dependency - it'll error saying it can't release due to snapshots since the version actually hasn't been updated yet.
The way you have the projects configured they are totally independent. You might as well be asking for the version of your log4j dependency to be the same as your current project B version.
While it won't be automatic, you should replace the versions of all references to Project A within Project B to use a property that is defined in the parent pom for Project B. Then, when you release Project A, you only have to change one pom so the project.a.version property is now the released version instead of SNAPSHOT. After the release of B you could then change it back to ${project.version} to keep them in sync.
As you admit, the right answer here is to re-arrange your project to have a common parent. Anything else is just a workaround.
However, it looks to me like versions:use-releases might achieve your goal. You can specify an includes list to ensure only project 1 dependencies are updated.
If you wanted this to be automatic, you could consider binding this goal to one of the lifecycle phases prior to compile.
Edit: sadly this looks like its not possible. At least, that's how I understand by the "Executes by direct invocation only" mentioned at the top of the page.
What are the best practices for software versioning and multimodules projects with Maven?
I mean, when I create a multimodules project with Maven, what is the best approach for the versioning? To use a single version for all the modules (defined in the top project)? To use a version for each module (defined in the POM of each module)? Is there another approach that I'm missing? What are the pros and cons of each approach?
In general, are the different modules released together (possibly sharing the same version number)?
Thanks
Honestly it depends on what you would like to do. Multimodule projects are created for multiple reasons, one of them being you only need to deploy what has changed instead of all modules.
Think about it this way: if you had a non-multi-module project and you only had to change one line in the services layer, you have to rebuild the entire project and deploy all of the code again...even though only your services layer will change.
With multi-module projects, you can regenerate your project and deploy only what changed...your services. This reduces risk and you're assured that only your services module changed.
You also have a multitude of benefits to using multi-module projects that I'm not listing here but there is certainly a huge benefit to NOT keeping your version numbers of your modules in sync.
When you build your project, consider deploying it to a repository that will hold all compatible jars together for builds (each build creates a new folder with the parent-most pom version number). That way, you don't need to keep documentation about which jars are compatible...they're all just deployed together with a build number.
I was looking for a solution for this exact problem myself and versions-maven-plugin was exactly what I needed. I don't like the release plugin communicating with the SCM system. The versions plugin does just what we need: it sets a new version number in all poms of the project:
mvn versions:set -DnewVersion=2.0.0
Then I can proceed with commits, tags and an official build server build...
EDIT:
The versions plugin depends on how a maven multi-module project has been organised: as a result, it often does not update all POM files in a complex multi-module project.
I've found that sed and find do the job much more reliably:
sed -i 's/1.0.0-SNAPSHOT/1.0.0-RC1/g' `find . -name 'pom.xml'`
Typically you create a multi-module project because you have deemed that the various modules are parts of a single whole. Maybe the client-piece, the controller-piece and the services-piece. Or maybe the UI with services.
In any case, it makes sense to have the version numbers for the various modules to move in lock-step. However Maven does not enforce that as a rule.
As to your question
are the different modules released together (possibly sharing the same
version number)
I would think so. That is one of the reasons for having it a multi-module project. Otherwise you could have the modules as independent projects.
Of course this is the kind of stuff that is rife with edge cases and exceptions ;-)
I had the same problem with a project I`m working on. I also decided to use separate versions and even the dependency to the parent pom only has to be updated if some of the managed dependencies change. (so mostly as #vinnybad describes it)
Two additions
exists-maven-plugin
With the usage of the "org.honton.chas.exists-maven-plugin" only the modules will be deployed to the repository that have actually changed, which is really great, because also the according docker-images will only be published if something has changed on one of the service. This avoids "polluting" the image repository with different but unchanged versions.
versioning
One main downside of the "separated versions" approach are the questions regarding versioning:
What's the current version of my project?
Which module versions work with each other? (even thought they don't directly depend on each other, one does rely on what another does, e.g. they share the database schema)
To solve that I put all module versions into the dependency management part of the parent pom, even if no other module depends on them. A "integration-test" module could solve that by depending on all of the modules - and of course testing them together.
This way I would be "forced" to update the parent pom with every change, since it's referring the released module versions. This way the parent pom would have the "leading" version and at the dependency-management block state the versions of all modules that are compatible with each other (which will be ensured by the integration test).