I have found out that most of poms in our project have defined a profile with exactly this definition:
<profile>
<id>default profile</id>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
</profile>
Given there is no profile called "default profile" defined in any of the parent poms, that would do anything, I don't see a point in this. Is there any? Could it possibly override some default maven behaviour or anything, or can it be safely removed?
This is aged, but I've come across this:
I have a parent pom, configured to run some plugins. However, I only ever want to run these plugins for child poms. When I want to deploy "this" pom, I really only want that maven copies it into the repo. So I define an empty profile and activate it when I deploy the pom. Maybe it's a hack, but it's kind of nice to not have to rely on and repeated plugin declarations in the child poms.
Related
I would like to download the JACOB dlls when they're not in my local repository.
As a consequence, I have those two profiles
<profile>
<id>use-jacob-dll</id>
<activation>
<file>
<exists>${settings.localRepository}/com/hynnet/jacob/1.18/jacob-1.18-x64.dll</exists>
</file>
</activation>
<dependencies>
<dependency>
<groupId>${jacob.groupId}</groupId>
<artifactId>jacob</artifactId>
<type>dll</type>
<classifier>x64</classifier>
<version>${jacob.version}</version>
</dependency>
</dependencies>
</profile>
<profile>
<id>download-jacob-dll</id>
<activation>
<file>
<missing>${settings.localRepository}/com/hynnet/jacob/1.18/jacob-1.18-x64.dll</missing>
</file>
</activation>
But, even when download-jacob-dll has accomplished its goal, a call to mvn help:active-profiles indicates the following
The following profiles are active:
- tests-for-eclipse (source: com.capgemini.admdt:kpitv:1.2.4-SNAPSHOT)
- download-jacob-dll (source: com.capgemini.admdt:kpitv:1.2.4-SNAPSHOT)
I suspect it is due to the fact that I use the ${settings.localRepository} in my activation property.
Question: Is it the cause of the failure? And if so, how can I activate my profile only when dependency is missing ?
Is it possible to use a maven property to activate a profile based upon a file?
No, as stated by the Maven documentation on profiles
Supported variables are system properties like ${user.home} and environment variables like ${env.HOME}. Please note that properties and values defined in the POM itself are not available for interpolation here, e.g. the above example activator cannot use ${project.build.directory} but needs to hard-code the path target.
However, from the POM documentation we also get that
a given filename may activate the profile by the existence of a file, or if it is missing. NOTE: interpolation for this element is limited to ${basedir}, System properties and request properties.
Hence, indeed no Maven properties except ${basedir} are allowed.
And if so, how can I activate my profile only when dependency is missing?
By hardcoded path to the dependency or concerned file would be a solution, even though not portable like the solution you meant.
Alternatively you could use a request property as mentioned by the documentation above, thus need to configure the activation with a property which then must be passed from the command line (more portable but more fragile as well):
<activation>
<file>
<missing>${path}/com/hynnet/jacob/1.18/jacob-1.18-x64.dll</missing>
</file>
</activation>
Then invoke maven as following:
mvn clean install -Dpath=path_to_local_rep
The solution above could be reasonable in some contexts like Jenkins jobs.
I currently work in big project built by Maven which has many integration tests modules which are marked as main (not testing) sources.
I am trying to create a profile which would skip compilation of these modules.
I expected gmaven plugin to allow "skip" configuration parameter but this is not the case.
Is there any way to skip module processing without pointing gmaven plugin to non-existent directory and without copy-paste of all modules except integration tests to a separate profile?
You can put the integration test modules in a separate profile of the parent pom where you list the modules. The profile should be active unless you disable it by setting a property when running the Maven build (-DskipIntegrationTestModules). (Don't use activeByDefault.)
<modules>
<module>my-project</module>
</modules>
<profiles>
<profile>
<id>build-integration-tests</id>
<activation>
<property>
<name>!skipIntegrationTestModules</name>
</property>
</activation>
<modules>
<module>my-project-integration-test</module>
</modules>
</profile>
</profiles>
You can find more details in the Maven Introduction to Build Profiles.
You should also know that it can be dangerous to have modules in build profiles because they could be accidentally left out when doing release builds. I think it should be OK in this case because the profile has to be deactivated explicitly.
This is the snippet of pom.xml from my project.
<properties>
<Port>2020</Port>
<threads>20</threads>
<test.suite />
<test.suite.path />
<useTag />
<useTestCase />
<args>-Dthreads=${threads} -Dtest.suite.path=${test.suite.path} -Dappenv=${test.app.env} -Dtest.suite=${test.suite} -DuseTag=${useTag} -DuseTestCase=${useTestCase}</args>
</properties>
when maven build is made, I am wondering how the variables test.suite, test.suite.path, useTestCase are set? I do not see it anywhere in the pom. but the Jenkins build is working fine and it has substituted values for these placeholders.
what is the use of using this kind of property setting. <variable/> rather than <variable>...</variable> ?
To say exactly how those properties are set in your case we need to see the entire pom structure including the parent pom(s) as well as your Jenkins job configuration.
However, I know of two ways that these properties can be set:
Through a profile in one of your parent poms
Through system properties when maven is invoked
My guess is that you have a profile in one of your parents that sets these properties. Something like this:
<profile>
<id>jenkins</id>
<properties>
<test.suite>...</test.suite>
...
</properties>
</profile>
And that this profile is activated on your Jenkins server. Look here for information how the profile can be activated.
The other option is that these properties are specified as system properties when maven is invoked from Jenkins.
As for why <variable/> is used over <variable></variable> it is a matter of taste. <variable/> means the same thing as <variable></variable> in XML.
I have the following profiles in my parent pom
<profile>
<id>P1</id>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
</profile>
<profile>
<id>P2</id>
<activation>
<file>
<exists>${project.basedir}/src/main/whatever</exists>
</file>
</activation>
</profile>
Why P1 is active in child POM and P2 isn't?
The directory ${project.basedir}/src/main/whatever, does not exist in the parent project, but exists in the child one.
Profile P2 is not activated because the path under its exists tag does not resolve to an existing path even though the directory ${project.basedir}/src/main/whatever exists. If you rewrite the property ${project.basedir} as ${basedir}, it should activate the P2 profile.
That should mean that the ${project.basedir} does not resolve to the project base directory as it should. The help:effective-pom shows that it does, though. I have reported this (MNG-5516).
Also I think that P1 will not be active if P2 is.
That is correct. Quoting the documentation for activeByDefault:
This profile (P1 in this example) will automatically be active for all builds unless another profile in the same POM is activated using one of the previously described methods. All profiles that are active by default are automatically deactivated when a profile in the POM is activated on the command line or through its activation config.
The word inherit got me confused, because the "profile inheritance" works in project aggregation but not in project inheritance.
To make things clear, I simulated this situation. Empty pom means that it is empty except for the standard model, group, artifact and version tags.
Simple scenario
Directory structure:
simple
\-pom.xml
pom content:
<profiles>
<profile>
<id>P1</id>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
</profile>
<profile>
<id>P2</id>
<activation>
<file>
<exists>${basedir}/dir/</exists>
</file>
</activation>
</profile>
</profiles>
If there is no dir directory mvn help:all-profiles outputs:
Profile Id: P1 (Active: true , Source: pom)
Profile Id: P2 (Active: false , Source: pom)
If there is dir directory mvn help:all-profiles outputs:
Profile Id: P2 (Active: true , Source: pom)
Profile Id: P1 (Active: false , Source: pom)
Project inheritance
Directory structure:
inheritance
|--child
| \-pom.xml // child pom
\-pom.xml // parent pom
Child pom is empty while parent pom has the profiles as in the simple scenario. Regardless of the existence of the inheritance/child/dir directory running mvn help:all-profiles from child directory outputs:
Profile Id: P1 (Active: false , Source: pom)
Profile Id: P2 (Active: false , Source: pom)
When running mvn help:effective-pom from child directory it shows that the profiles are indeed not inherited. It behaves as documented:
Elements in the POM that are merged are the following:
dependencies
developers and contributors
plugin lists (including reports)
plugin executions with matching ids
plugin configuration
resources
No profiles are mentioned here.
Project aggregation
Directory structure:
aggregation
|--module
| \-pom.xml // module pom
\-pom.xml // aggregator pom
Module pom is empty while aggregator pom has the profiles as in the simple scenario. If there is no aggregation/module/dir directory running mvn help:all-profiles from module directory outputs:
Profile Id: P1 (Active: true , Source: pom)
Profile Id: P2 (Active: false , Source: pom)
If there is aggregation/module/dir directory running mvn help:all-profiles from module directory outputs:
Profile Id: P2 (Active: true , Source: pom)
Profile Id: P1 (Active: false , Source: pom)
When running mvn help:effective-pom from module directory it shows that the profiles are inherited. This is not explicitly documented:
Project inheritance
If you have several Maven projects, and they all have similar configurations, you can refactor your projects by pulling out those similar configurations and making a parent project. Thus, all you have to do is to let your Maven projects inherit that parent project, and those configurations would then be applied to all of them.
Notes:
That does not apply to profiles, as it has been shown.
Runnnig a maven build from inheritance directory will run only parent build.
Project aggregation
And if you have a group of projects that are built or processed together, you can create a parent project and have that parent project declare those projects as its modules. By doing so, you'd only have to build the parent and the rest will follow.
Notes:
Runnnig a maven build from aggregation directory will run the build of each module and the aggregator (the actual order is determined by maven based on different criteria).
Conclusion
Profiles can be defined globally, per user or per project. Since the aggregated projects are built together (in the same build) some sort of profile resolution must be run to calculate the active ones. So this is the confusing part:
When projects are inherited profiles are not inherited from parent pom to child pom.
when projects are aggregated profiles are inherited from aggregator pom to module pom.
This was tested this using Maven 3.1.0. and 3.0.5.
Just to clarify on this, Maven Profiles are in fact inherited. For a reference to another SO question see: Inheriting Maven profiles. I have successfully inherited profiles in my project and no additional work is needed.
As for the original question, you have a variable defined in the exists element. According to the documentation:
As of Maven 2.0.9, the tags and could be
interpolated. Supported variables are system properties like
${user.home} and environment variables like ${env.HOME}. Please note
that properties and values defined in the POM itself are not available
for interpolation here, e.g. the above example activator cannot use
${project.build.directory} but needs to hard-code the path target.
So, what I get from that is that ${project.basedir} cannot be used and will not work. If however you have it defined as an environment variable, it will work.
One caveat that I found is that in the parent pom <plugin-management> should be used to configure the plugins. However, for within the profiles I find that <plugin-management> must not be used in order for the profile-specific configuration to work.
The problem is not with inheritance but with interpolation (i.e. which values are supported for ${...}): file-based profile activation only supports limited interpolation: see http://maven.apache.org/pom.html#Activation
So ${project.basedir} isn't supported but only ${basedir} (and system properties).
For more details, you can have a look at the model building algorithm: http://maven.apache.org/ref/3.2.1/maven-model-builder/
Full model interpolation happens after profile activation: so even if your effective pom shows interpolated value for ${project.basedir}, the value isn't calculated when profile activation happens.
In Maven 3.2.2, there are multiple enhancements regarding this: documentation in http://jira.codehaus.org/browse/MNG-5590, warning at runtime in http://jira.codehaus.org/browse/MNG-5608 and better effective pom result http://jira.codehaus.org/browse/MNG-5612
In general, Maven profiles are not inherited (see http://jira.codehaus.org/browse/MNG-5127 for a discussion and links to blog posts that might be useful). I've had success doing something like this:
<!-- Parent -->
<profile>
<id>P2</id>
<activation>
<file>
<exists>${project.basedir}/src/main/whatever</exists>
</file>
</activation>
<!-- all the things you want to define for the child POMs -->
</profile>
<!-- Child -->
<!-- Include only the activation block, which must match parent's exactly -->
<!-- Whatever is in the parent will be inherited -->
<profile>
<id>P2</id>
<activation>
<file>
<exists>${project.basedir}/src/main/whatever</exists>
</file>
</activation>
</profile>
Also I think that P1 will not be active if P2 is. This is because <activeByDefault> is true for P1. The element name is a little misleading in my opinion. "Active by default" implies "always active" when it really means "active only if no other profile in this POM is active."
The above discovered using Maven 3.0.x.
Remove the P2 from the second profile that has the file based activation.
<profiles>
<profile>
<id>P1</id>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
</profile>
<profile>
<id>P2</id>
<activation>
<file>
<exists>${basedir}/dir/</exists>
</file>
</activation>
</profile>
</profiles>
I have a dependency which I have installed in Maven local repository and is being used locally but is not available on deployment server. I use that dependency using Class.forName(...) so there will be no problem if it's missed from classpath on deployment server.
Is there any way to tell Maven to ignore a dependency if it failed to resolve it?
I doesn't seem that <scope> or <optional> can solve this problem, but it may be possible to do it with <profiles> if there is any way to activate/deactivate a profile based on dependencies availability.
Short answer: no.
Long answer: Once dependency is declared - either in common part or in an active profile - it must be resolvable when Maven attempts it; otherwise the build fails.
If maven allowed the requested behavior, the reproducibility of build would suffer a lot.
If obscurity and irreproducibility is not an issue for you, here is a hint how to do it:
call external ant from your pom.xml, using either exec-maven-plugin or maven-antrun-plugin
in the ant code, use artifact:dependencies from Maven Ant Tasks
wrap it in ant-contrib's trycatch block
In any case, I strongly discourage including such things into maven build. Having it as separate functionality, invoked via ant from commandline, might often be enough.
assuming the missing dependency is only important in the local environment you can use a combination of profile and activation via your .m2/settings.xml
You remove the dependency from your general dependencies and move it as a referenced dependency into a profile of your pom.xml (Project level profile) and activate the profile through your m2/settings.xml.
You may also remove the dependency completly from your pom.xml and move the dependency into a profile which resides in your .m2/settings.xml (User level profile)
see the introduction to profiles section
another way which fits your needs maybe better
The activation of the above mentioned profile based on the presence of the file in .m2/repository/local/dependency/1.0.0-Snapshot/local.jar
<profiles>
<profile>
<activation>
<file>
<exists>/home/user/.m2/repository/local/dependency/1.0.0-Snapshot/local.jar</exists>
</file>
</activation>
...
</profile>
</profiles>
Bizarrely, I had a problem with maven where it would say "cannot resolve dependency" (of some weird transitive dependency that didn't exist anymore), but it only failed with that error message if my ~/.m2/settings.xml had a
got my jars from a local repository
<profiles>
<profile>
<id>nexus</id>
<repositories>
<repository>
<id>a name</id>
<url>http://somewhere/local/a</url>
</repository>
If I changed it to mirror, it would not fail.
<mirrors>
<mirror>
<id>a name</id>
<name>an awesome description</name>
<url>http://some/where/local</url>
<mirrorOf>external:*</mirrorOf>
(same repo). Go figure.
Please try to exclude the dependencies from the POM
<executions>
<execution>
<id>***failed dependency Id***</id>
</execution>
</executions>