Building an Eclipse plugin using Maven - maven

I am trying to configure Maven to build an Eclipse application (Eclipse plugin packaged with all of the Eclipse EXEs etc).
I have already Mavenised dozens of dependencies of the project and deployed them to our internal Nexus (OSS) server. I have also installed the Nexus P2 Repository Plugin and the P2 Bridge Plugin (2.6.3-01) and the Nexus Unzip Plugin (0.12.0). I can browse to the .meta/p2 folder of our group repository, but it is currently empty.
This should be a lot simpler than it currently appears to be. I'm targeting Eclipse 3.4.2 (Ganymede) on Windows. If it makes any difference, we actually deploy our application packaged as a stripped-down/customised Eclipse installation.
eclipse-repository
When I run maven against a pom with <packaging>eclipse-repository</packaging> I get the following error:
[ERROR] Missing requirement: MyApp 0.0.0 requires
'org.eclipse.equinox.executable.feature.group 0.0.0'
but it could not be found
...where do I get that from, and how do I add it to Nexus?
When I run maven against a pom with <packaging>eclipse-plugin</packaging> I get the following error:
[ERROR] Missing requirement: MyApp 0.0.0 requires
'bundle org.eclipse.ui 0.0.0'
but it could not be found
...but I found the following directories on my local file system (suspect itp-04-rcp generated the first one):
D:\maven\repository\p2\osgi\bundle\org.eclipse.ui\3.6.2.M20110203-1100
D:\maven\repository\p2\osgi\bundle\org.eclipse.ui\3.7.0.v20110928-1505
Tycho POM-First artifacts
I've also tried the pom-first-dependencies and manifest-first-dependency combo: http://wiki.eclipse.org/Tycho/How_Tos/Dependency_on_pom-first_artifacts
I don't understand how this works - I can build itp02 from Git. I can see that it builds two bundles:
+---------------------+---------------------+--------------------------------------+
| artifactId | Bundle-Name | Bundle-SymbolicName |
+---------------------+---------------------+--------------------------------------+
| pomfirst-bundle | pomfirst-bundle | tycho.demo.itp02.pomfirst-bundle |
| pomfirst-thirdparty | pomfirst-thirdparty | tycho.demo.itp02.pomfirst-thirdparty |
+---------------------+---------------------+--------------------------------------+
...but how does build02 pick these up? The only bit that seems relevant is:
Import-Package: tycho.demo.itp02.pomfirst
...that doesn't have anything to do with either of the Bundle-Names.
Felix Maven Bundle Plugin
I tried the Felix maven-bundle-plugin. I include all of my regular maven dependencies in a pom with <packaging>bundle</packaging>.
mvn deploy creates something at /nexus/content/repositories/snapshots/.meta/p2/plugins. I can download the jar via a browser, but all of the dependency jars are named "artifact-vresion" rather than "artifact_version" - is that right?
mvn bundle:bundleall creates an OSGI bundle for each of the transitive dependencies, but I'm not sure what to do with them from here.
mvn bundle:deploy refuses to do anything unless I specify -DremoteOBR and probably a few other parameters which I don't really understand.

The 'org.eclipse.equinox.executable.feature.groug' seems to be necessary if you build an eclipse product which includes the native launchers ("include laucher" property set to true in product configuration). Try to add the feature to your platform definition (e.g. copy from eclipse p2 repo or your running eclipse IDE).
See also https://bugs.eclipse.org/bugs/show_bug.cgi?id=407272
Regards,
Paolo

To solve the Problem concerning the missing dependencies:
[ERROR] Missing requirement: MyApp 0.0.0 requires
'bundle org.eclipse.ui 0.0.0'
but it could not be found
seems that your Feature/Plugin MyApp requires to download the org.eclipse.ui Plug-in before it can be installed.
You should check your settings from your configuration-pom like this:
<properties>
<tycho.version>0.25.0</tycho.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<repository.url>http://download.eclipse.org/releases/neon</repository.url>
</properties>
<repositories>
<repository>
<id>NeonRepository</id>
<url>${repository.url}</url>
<layout>p2</layout>
</repository>
if you have set up your self-hosted p2 repository, make sure that the page is correctly build.
You can check this if you select(in eclipse) Help -> Install New Software.
Eclipse should show the provided parts.
If nothing is shown, even if you have deselected every checkbox, you should check your p2-repository.
It should contain the "features" and "plugins" container as well as the artifacts.jar and content.jar.
If you have only the two folders, you should run
eclipse -application org.eclipse.equinox.p2.publisher.UpdateSitePublisher
-metadataRepository file:/<some location>/repository
-artifactRepository file:/<some location>/repository
-source /<location with a site.xml>
-configs gtk.linux.x86
-compress
-publishArtifacts
in a CLI/Shell.
For more Information check the eclipse documentation.

Can you make maven/tycho instantiate a target platform against which you can build your source plugins? http://www.vogella.com/articles/EclipseTycho/article.html

Related

How to fix not finding a plugin artifact?

I am getting this error: [ERROR] Plugin org.apache.maven.plugins:maven-surefire-plugin:2.12.4 or one of its dependencies could not be resolved: Could not find artifact org.apache.maven.plugins:maven-surefire-plugin:jar:2.12.4 in nexus-xyz-plugin
I tried to run maven with dependecy:tree, but I can't see surefire, and I dont know why it is looking for this specific version 2.12.4 which is not specified in my pom!
Even the surefire plugin is not defined in my pom, but I have the assembly plugin not sure if assembely is dependent on surefire
Note that I only get the error when running mvn package, however when running mvn compile the build succeeds
Version 2.12.4 of the maven-surefire-plugin is always added to the pom by maven version 3.x unless you depend on a specific other version.
Maven has a so called super pom that you get for free, but that doesn't list surefire: https://maven.apache.org/ref/3.8.5/maven-model-builder/super-pom.html
However it is added to the pom, i've checked this with maven 3.3.9. You can verify this by running mvn help:effective-pom.
Reference with the same problem: No surefire plugin in my pom - How does it show surefire output?
These plugin versions are part of the default bindings for lifecycle executions, in this case of the test phase. So these plugins are always included if not specified.
See for reference:
https://maven.apache.org/guides/introduction/introduction-to-the-lifecycle.html
https://maven.apache.org/ref/3.8.5/maven-core/default-bindings.html
Maven default life-cycle and plugins section
Normally this plugin should be available in maven central, check if you have a <pluginRepository> in your (effective) pom that references https://repo1.maven.org/maven2/
Some other things you can check:
Open the file .m2\repository\org\apache\maven\plugins\maven-surefire-plugin\2.12.4\maven-surefire-plugin-2.12.4.jar.lastUpdated and check the error message for each repository. Check why it can't reach maven central; is it missing from the list or giving an error? This might be a company firewall/policy issue perhaps? Or is it giving an error on HTTPS/TLS protocol level?
Check if you can add maven central to your repositories list if it's missing somehow (should be included by default). Check if it's HTTP or HTTPS, only secure is supported now.
Run your maven command with -X for debug mode to investigate further
An alternative is to add the latest version of surefire to your project that is available in your plugin-repository, and perhaps disable it if you're not executing unit tests.
See Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.12:test (default-test) on project.

How to fix 'Missing requirement' error in Maven on Windows

I'm trying to build dbeaver and get the following error when running mvn package:
[ERROR] Cannot resolve project dependencies:
[ERROR] Software being installed: org.jkiss.dbeaver.slf4j 1.0.0.qualifier
[ERROR] Missing requirement: org.jkiss.dbeaver.slf4j 1.0.0.qualifier requires 'bundle org.slf4j.api 0.0.0' but it could not be found
I'm running on Windows 10 and using apache-maven-3.6.1. The strange thing is that when I try the same steps on Linux it builds without problem.
Update
Possible cause is maven 3.6.1 https://www.eclipse.org/lists/tycho-user/msg08177.html
Original post
The problem here, I presume, is that https://dbeaver.io/eclipse-repo/ p2 site is missing slf4j bundle and Tycho (?) cannot resolve the requirement. I still do not know how to make standalone maven build work, but here is an ugly workaround on how to build Windows binary with Eclipse (and embedded maven).
You can use p2-maven-plugin to build that missing bundle yourself. Instead of setting up a brand new project, you can temporarily modify product\localRepository\pom.xml to have a single artifact like
...
<artifacts>
<artifact><id>org.slf4j:slf4j-api:1.7.26</id></artifact>
</artifacts>
...
Now build that (product\localRepository\) project and start jetty
mvn p2:site
start mvn jetty:start
Now you can add this interim update site (http://localhost:8080/site/) to your Eclipse installation (Help -> Install New Software) and install slf4j. You should already be able to run DBeaver from within Eclipse.
To build a binary, add this interim repo into main pom.xml file, e.g. right after local-contrib one.
<repository>
<id>more</id>
<url>http://localhost:8080/site/</url>
<layout>p2</layout>
</repository>
Then go to Run Configurations -> Maven Build -> dbeaver, enter package goal and tick Skip Tests, click Run and go have some coffee.
As you can see Eclipse uses some sort of embedded maven runtime, so I guess it resolves things differently.
Note that if you are updating your local git repo, you might need to update your Eclipse project big time. I was unable to do it with right clicking on the project -> Configure -> Configure and Detect Nested Projects :( But deleting Eclipse project and nested projects (without deleting underlying files) and re-importing Maven project did the trick for me.
There is also an open issue for this https://github.com/dbeaver/dbeaver/issues/6115 .

Installation and deployment of maven test-jar

I've discovered the wonderful test-jar facility in Maven: https://maven.apache.org/plugins/maven-jar-plugin/examples/create-test-jar.html
But it may so happen that one project needs to use the test-jar of another project. From https://stackoverflow.com/a/6469256/421049 and experimentation, it would seem that using mvn install does not install the test-jar to the local ~/.m2/repository. So how does one project on my machine use the test jars of another project not in the same aggregate POM?
Yet it would seem from Maven deploy not to upload test jar that deployment of a project to Maven Central does in fact deploy the test-jar? So I can deploy it to Nexus but not install it locally? And if I deploy it to Nexus, will my local project using a dependency of <type>test-jar</type> go find it on Maven Central?
It turns out that maven-jar-plugin does in fact install the test-jar (e.g. foo-1.2.3-tests.jar) in the local Maven repository ~/.m2/repository/.... Wonderful!
My problem is that I had inadvertently configured the maven-jar-plugin to be in a separate profile named release. (I had copied and pasted to the wrong location in my POM.) That's why the test-jar didn't show up in my local repository after a mvn install, and that's why it suddenly showed up later (after I used -P release once in testing), and I thought I had just missed it when I looked the first time.
I move the maven-jar-plugin to the <build> section and everything is working fine: the test-jar gets put into the local maven repository using mvn install.
In my case, I was setting maven.test.skip for a particular build profile. That property actually causes tests to not be compiled/installed, thus also preventing their deploy. The solution was to set the skipTests property instead.

Do we have to include jar files in eclipse project if we are using maven?

I am new to maven.
The POM file in maven contains all the dependencies that we need in our project.
So we don't have to externally add any JAR's to the buildpath in eclipse.Right?
That's right. Maven will download dependencies and M2Eclipse (Eclipse plugin for integrating Eclipse with Maven) will setup a build path for you.
Two Solutions - 1 Using Eclipse IDE
Install the Maven (M2E Eclipse Plugin) if you use older version of eclipse, If you download the latest eclipse.
Point your settings.xml and create a maven project from your eclipse, it is better keep Group Id as com.yourcompany.app Artifact Id as yourProjectName and Version 0.0.1-SNAPSHOT depends on your Architecture Standards set by your company. Also Packaging can be as WAR file for WebApplication, EAR file for Enterprise Application. You can find the numerous list of examples from Maven Site.
2 From Command Line
Install Maven from Apache Maven site, Would recommend to go for the latest version -apache-maven-3.3.9-bin.zip.
Set the Maven Home in the Environment Variables as shown in the below figure.
Edit Your Path variable as %MAVEN_HOME%\bin, verify your installation by using this command from your command prompt. It should display the Maven Home and Java Version, which confirms your maven successful installation.
Paste your settings.xml (C:\apache-maven-3.3.9\conf) given by your build team or Architecture team for accessing your internal repository. And keep a backup of the original settings.xml (which is default download from Maven site)
Run these commands from your command prompt.
mvn eclipse:clean -e
mvn eclipse:eclipse -e (which will automatically set your project build path as shown in the below figure)
It will resolve your compilation issues and your project is ready as an deploy-able artifact

Building a p2 repository by resolving Tycho features from a Maven repository

I'm trying to build a p2 repository from Tycho feature artifacts which are deployed in a remote Maven repository, without having to install the artifacts into the local Maven repository first (as in Tycho fails to resolve reference from product to eclipse-feature from a different reactor build), and without having to build all features and the repository together in a single reactor build.
Background
I have a multi-module Tycho project that builds several Eclipse plugins and features.
So that I can build each module separately - and so that I can reference OSGI artifacts in our Nexus Maven repository - I have enabled <pomDependencies>consider</pomDependencies> in my target platform, and added Maven dependencies between the modules or to the repository artifacts as usual with <dependency/> elements.
This works well - I can build the features or run the plugin tests without their dependant plugins being either in my local Maven repository or in the same reactor build. For example, when I run mvn test on a plugin test project, the relevant dependencies will be downloaded from Nexus and Tycho will happily resolve the Import-Packages in my manifest against these, build everything and run the tests. So far so good.
I would like to generate a p2 repository from these features so that I can install them in Eclipse from an update site, and the advertised way to do this is with the eclipse-repository packaging type. But here the plan falls down - Tycho doesn't seem to be able to resolve feature dependencies when building repositories in the same way as it can resolve plugin dependencies when building features. All attempts yield:
[ERROR] Cannot resolve project dependencies:
[ERROR] Software being installed: my.eclipse.repository raw:0.0.1.'SNAPSHOT'/format(n[.n=0;[.n=0;[-S]]]):0.0.1-SNAPSHOT
[ERROR] Missing requirement: my.eclipse.repository raw:0.0.1.'SNAPSHOT'/format(n[.n=0;[.n=0;[-S]]]):0.0.1-SNAPSHOT requires 'my.prj.eclipse.project.feature.feature.group 0.0.0' but it could not be found
There are two ways I have successfully built the p2 repository:
As part of the same reactor build. If I make the eclipse-repository a module within the Tycho multi-module project, and build the whole project at once with e.g. mvn verify, the features are resolved fine. But I don't want to do this. I would prefer to build modules individually. This means our CI can have an indicator for each module, and we can immediately see what module tests have failed in; it gives us opportunities for parallelising builds; and we avoid having to be constantly running builds on modules that haven't changed. It would be a shame to have to use a monolithic Maven build.
If I install the Tycho project into my local Maven repository, by running mvn install on the dependency. But I don't want to do this either, because this would mean the build is inherently irreproducable, as it would be sensitive to the state of the local repository. Our CI is currently set up to maintain a Maven repository per job and to completely wipe it at the start of execution, to shield us from this potential messiness.
So my question is: is there a third way? Is there any way I can get the Tycho plugin responsible for building eclipse-repository packaging types to download features from a remote Maven repository? Or any other way I can build the p2 repository from plugins that have been individually built and deployed to the Maven repository?
Things I've tried include:
specifiying the Maven feature depedencies as both jar and eclipse-feature
explicitly adding the features to the target platform, like
...
<artifactId>target-platform-configuration</artifactId>
<version>${tycho.version}</version>
<configuration>
<dependency-resolution>
<extraRequirements>
<requirement>
<type>eclipse-feature</type>
<id>my.prj.eclipse.project.feature</id>
<versionRange>0.0.0</versionRange>
</requirement>
...
The closest thing I've found to a decent solution is have a multi-module Tycho project that just contains the repository and features.
feature-project
|- feature1 (eclipse-feature)
|- feature2 (eclipse-feature)
|- repository (eclipse-repository)
Building this works - all plugins added to the top-level POM are downloaded from Nexus, available for inclusion in each feature and included in the generated repository.
However this is far from ideal because I can no longer store my features logically alongside my plugins; they need to be in separate project hierarchies. Attempting to build the features and repository separately, like with mvn clean verify -pl :feature1,feature2,repository, fails presumably due to Bug 380152.
Is there a better way? Any help would be gratefully received.
Many thanks
(As an aside: building the repository with mvn clean verify -Dtycho.localArtifacts=ignore will succeed if the features are present in the local Maven repository, and won't show you the warning that artifacts are being resolved from the local repo... is this a bug?)
I am pretty impressed by your thorough analysis. You've almost got everything covered which is possible with the current Tycho version (0.22.0) - except for the solution which is so unintuitive that I wouldn't have expected anyone to be able to guess it (see below). Note however that there is a small fix required to also make the solution work for SNAPSHOT artifacts.
But first, I'd like to provide some technical (and historical) background for what you have observed:
pomDependencies=consider only works for plug-ins: The use case for this functionality was to allow referencing plug-ins (or more precisely OSGi bundles) from Maven repositories. So when the flag is set and the project has dependencies to JARs, Tycho will check if they are OSGi bundles, generate the p2 metadata for them on-the-fly, and add them to the target platform. There is no similar support for feature JARs because these usually don't exist in Maven repositories.
But what about Tycho-built projects? These may deploy into Maven repositories! Yes, this is true, and this is why I tried to extend the pomDependencies concept to allow for what you are trying to do. The idea was that every time Tycho considers a POM dependency for the target platform, it also checks if the p2 index files ...-p2metadata.xml and ...-p2artifacts.xml exist. However this turned out to infer a massive performance penalty because it generally takes very long for a Maven repository server to figure out that an artifact does not exist. So the remote download was disabled, and replaced with a look-up in the local Maven repository. In this way, two Tycho builds could set -Dtycho.localArtifacts=ignore and would still be able to exchange the artifacts specified in the POM via the local Maven repository.
Knowing these implementation details, we get to the following solution: Instead of only adding a POM dependency from the repository to the feature artifact, you also need to add dependencies to the p2metadata and p2artifacts files. Example:
<dependencies>
<dependency>
<groupId>myproject</groupId>
<artifactId>myproject.feature</artifactId>
<version>0.1.0-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>myproject</groupId>
<artifactId>myproject.feature</artifactId>
<version>0.1.0-SNAPSHOT</version>
<classifier>p2metadata</classifier>
<type>xml</type>
</dependency>
<dependency>
<groupId>myproject</groupId>
<artifactId>myproject.feature</artifactId>
<version>0.1.0-SNAPSHOT</version>
<classifier>p2artifacts</classifier>
<type>xml</type>
</dependency>
</dependencies>
This makes Maven also download these p2 index files, so Tycho recognizes the main artifact as Tycho artifact. In this way, you can also get an eclipse-feature into the target platform via POM dependencies - at least almost: With 0.22.0, the repository build passes, but the feature.jar artifact is missing. I already debugged this issue, and it is easy to fix.
Obviously the syntax with three <dependency> elements for every actual dependency is not nice. It should be possible to boil this down to a single p2artifacts element - but this is more work. In case you are interested in this feature, you could open an enhancement request in Tycho's issue tracker.

Resources