I'm making a case for moving our builds from Maven to Gradle. Below are a few of the Maven command-line options my team finds useful. What are the Gradle equivalent choices?
-am,--also-makeIf project list is specified, also build projects required by the list
-amd,--also-make-dependentsIf project list is specified, also build projects that depend on projects on the list
-o,--offline Work offline
-pl,--projects Build specified reactor projects
instead of all projects
-rf,--resume-from Resume reactor from specified project
Maven Examples:
I only want to build the sub-project I'm working on and its dependencies.
mvn install --also-makeIf --projects :my-sub-project
After fixing an build issue, I want to start the build from the point of failure.
mvn install --resume-from :my-sub-project
I don't want to download external dependencies from an central repo.
mvn install --offline
Here are some rough analogues:
-am: buildNeeded (This triggers a full build of all upstream projects; building those parts of upstream projects that are required to fulfill the command at hand is automatic in Gradle.)
-amd: buildDependents
-o: --offline
-pl: :subproject1:build :subproject2:build
-rf: No direct analogue (not reliable, wouldn't work for parallel builds, etc.), but Gradle's incremental build will get you to the "resume point" quickly.
Note that Gradle's core concepts differ significantly from Maven's. To give one example, in Gradle build order is solely determined by task relationships, and there is no such concept as an execution dependency between projects. Due to these differences, some Maven features aren't necessary or useful in Gradle, some you get for free, and some come in a different form.
Related
I am learning about Jenkins and I have to explore some existing build jobs that others wrote (in the company that I'm working).
So I am trying to understand a job which uses mvn command.
So under the build part (inside the job), I see these details:
Maven version: 3.0.5
Root POM: pom:xml
Goals and options: clean install -U -Pnotest,docs
I'm trying to understand what this mvn command means?
I tried to google it: "clean install -U"
But I didn't find what the parameter U means.
And I don't know what is "-Pnotest,docs".
can you guide me regarding how I can find what's it? (maybe "-Pnotest,docs" is from a xml file or it's from the artifactory etc..)
Thanks a lot!!!!
-U Forces a check for miss releases and updated snapshots on remote repositories
If Maven is regularly used in your company, and you will have to work with it on a day-to-day basis, I would advise you to find a mentor (any colleague that knows the tool well and is ready to share its knowledge with you) and work with them. Maven, when you first look at it, can be quite of a mouthful and you'll learn it more efficiently with their help.
For the problem at hand, Elarbi Mohamed Aymen's answer already tells you what the -U flag corresponds to. As for -P, it is used to activate profiles (in your case notest and docs). These profiles are usually defined in the pom.xml of the project being build.
See Running Apache Maven for the basic commands, and as advised on that page run mvn -h to have the complete list of flags the command can use.
Maven is one of the mechanism how to handle the build process and check project dependencies, especially for Java.
One of the option can be to have physically included dependencies (artifacts / libs) in the project, but its not so useful- in case of new version, you have to replace the file, sometimes you are using same lib in more apps, ten you have to handle it manually in all projects.
Except this, there is the maven- it has a global repository with shared artifacts / libs , which are common used- ref. https://repo1.maven.org/maven2/.
Except this, you can make your own libs/ artifacts in this case, its a modules / applications which are reusable, then you are storing it in private repository- this is the artifactory.
When you want to build your project, in case of maven project you have pom.xml , which is like manual for maven what to do / how to build.
clean and install are common goals, clean will wipe your local maven repository, install will download them again, with parameter -U it force to download them.
You can define your own goals in pom file, eg. to "tree build"- build some dependent modules, then build parent project.
Eg. with -D you pass parameters to the maven eg.
mvn archetype:generate -DgroupId=com.mycompany.app -DartifactId=my-app
- that will generate new project, based on given archetype- "template", with the given groupID and artifactID- groupID can be eg. company name, artifactID is then the name of specific app / component.
-P,--activate-profiles <arg> Comma-delimited list of profiles
to activate
-D,--define <arg> Define a system property
I'm building a big project using Tycho.
Trying to build offline after one online build is successful, but every time I build, it costs me about 20mins to resolve dependencies.
For other reasons, build fails and I have to try many times. The wasted time got me crazy. Is there any way I can skip the "Resolving dependencies" step?
Once you build your project, i.e. you hit the install lifecycle phase, Maven will have the dependencies pasted under your local repository.
Unless you force dependencies reloading, Maven will go for an offline installation since all dependencies are there (that is the main purpose of saving artifacts locally).
That is the second build should be faster and straightforward.
If you are working within Eclipse, make sure it is using a local copy of Maven. Otherwise, the -o option should be fine if no snapshot dependencies are there:
mvn -o
I tend to avoid using mvn install in my multi-module projects because I feel like I then don't know which exact version of a submodule is then used when building / launching other submodules (particularly when switching between branches very often).
I tend to use mvn package a lot and then mvn verify.
I'm now facing the issue in a FOSS project (a Maven archetype moreover) where I'd like to use Maven's best practices.
It's a multi-module project with a webapp submodule depending on the other modules, and what worries me is the ease of development along with mvn jetty:run (or jetty:start).
Currently, I defined 2 profiles:
prod, the default one, declares dependencies on the other submodules;
dev on the other hand does not depend on the other modules, and configures the jetty-maven-plugin by adding the other modules' output directories as extraClasspath and resourcesAsCSV.
That way, I can mvn package once and then cd webapp && mvn jetty:start -Pdev and quickly iterate, reloading the webapp without the need to even stop the server.
AFAICT, extraClasspath was added for that exact purpose (JETTY-1206).
I've been pointed at the tomcat7-maven-plugin which can resolve modules from the reactor build when using Maven 3 (and I raised an issue to bring the same to Jetty: JETTY-1517), but that hardly solve my
If I hadn't removed the dependency on the other submodules from in dev profile, I'd have had to do an mvn install first so that validating the POM doesn't fail, even if jetty:start doesn't use those dependencies afterwards.
So here's my question: is mvn install really that common? or my approach of putting the intra-reactor dependencies only in the prod profile OK?
(note that I have the exact same problem with the gwt-maven-plugin, so please don't tell me to simply switch to Tomcat; that wouldn't even work actually, details here)
The mvn install is common in particular in relationship with multi-module builds, cause it will give you the chance to run a single module from your multi-module build.
This can be achieved by using:
mvn -pl submodule LifeCycle
I just found a workaround (which seems logical as an afterthought): https://jira.codehaus.org/browse/JETTY-1517?focusedCommentId=306630&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-306630
In brief: skip the plugin by default in the parent module then re-enable it where needed.
This however only works if the plugin can be skipped (i.e. has a skip configuration) and is only used in one specific submodule, and it has to be selectively done for each plugin you need/want to run that way (in my case, jetty:run and gwt:run).
I do most of my development on my laptop. For the projects I'm currently working on, my local repository is really more of a temporary holding area. I run mvn install all the time. Putting artifacts in one's local repo is the only way I know of to share built artifacts between projects, especially if you are working on projects which are related but are not (and should not be) part of the same multi-module build.
When I'm done developing I commit changes to the shared SCM and let Jenkins build & deploy the code to the shared remote repo. Then I either blow away the changed projects in my local repository so the next build brings down the freshly built artifacts, or I run Maven with -U to force updates.
This works well for me, YMMV.
What is the true way of building multi-module maven project: via package or via install if NONE of the modules will be a dependency for another project? I think in this case package is the only way to build it but I see how people IMO abuse the install goal. And I don't get why.
Is there any official considerations on how the multi-module project should be built?
UPD: I have only one explanation. Sometimes people just unaware of -pl, -am and -rf maven options. Thus it leads them to install the modules' artifacts into repository when they want to build part of the reactor.
if none of the projects is a dependency of any other project you have a weird setup. why build them together if they don't belong together?
Sometimes people just unaware of -pl,
-am and -rf maven options
in a normal setup, where there are dependencies between modules, these options (at least -rf) don't work if the modules aren't installed.
OK, you are using a dependency management system without dependencies. Yes, you can use package instead of install. But you are not avoiding bad usage patterns, you are either missing out on features or grouping things together that don't belong together.
Is it possible to do?
The environment: Multimodule pom consists of 3 modules: mm1, mm2, mm3. Module mm2 has mm1 as dependency. It is possible to build parent pom without any errors.
The question: Is it possible to build single module mm2 (i.e., run maven from mm2 base directory) without installing mm1 into local repository?
Thanks.
I'm not sure what you mean exactly by "without installing mm1 into local repository". Do you mean previously to building mm2 or never?
In doubt, maybe one of the new build options announced in the Maven Tips and Tricks: Advanced Reactor Options blog post can help:
Starting with the Maven 2.1 release,
there are new Maven command line
options which allow you to manipulate
the way that Maven will build
multimodule projects. These new
options are:
-rf, --resume-from
Resume reactor from specified project
-pl, --projects
Build specified reactor projects instead of all projects
-am, --also-make
If project list is specified, also build projects required by the list
-amd, --also-make-dependents
If project list is specified, also build projects that depend on projects on the list
I was specifically thinking to the -pl and -am options. To build a subset of the modules, run the following from the root directory
$ mvn --projects mm2 --also-make install
However, I'm not sure this answers your question (which is not totally clear for me).
Without automatic installing not, but it's possible to build only choosen projects. You need to have multi module build (I'm assuming you do). In reactor mode every command need to be run from the root of reactor.
So in your case:
mvn reactor:make -Dmake.folders=mm2
In this case you build mm2 module and modules on which it depends (mm1).
Useful links:
Maven reactor plugin reference
Maven book reactor chapter
From book examples I build only project persist and his dependency project model. Others projects are untouched with
mvn reactor:make -Dmake.folders=sample-persist
alt text http://www.sonatype.com/books/maven-book/reference/figs/web/running_aro-dependencies.png
Other useful command is reactor:make-dependents which build projects that depend on X.
This goes against the principle of dependencies of Maven2. What is the interest of doing that exactly?
However, we can imagine to define the mm1 dependency of mm2 as a system dependency:
<dependency>
<groupId>...</groupId>
<artifactId>mm1</artifactId>
<version>...</version>
<scope>system</scope>
<systemPath>../mm1/target/</systemPath>
</dependency>