Maven install local usage when using a repository manger - maven

I am lacking some basic understanding of using a repository manager for our projects. What I don't know is how, if I use a repository manager, if I run a local install command Maven doesn't deploy the package to something like a shared Nexus instance. I seem to have some confusion between local repositories and shared ones when using a repository manager.
Apologies for the naivity and for not testing this myself. We have started versioning our application and using a shared file system approach to getting artifacts and are left with a few questions about what, within the scope of what we are currently doing, will be gained by using a repository manager instead. We do use TeamCity as a build server which is deploying to that currently used file system. I need to know some answers to a few questions before POCing a repo manager.

install is specific to the local repository.
From Maven's point of view whether a remote repository is hosted by your repository manager or is completely external has no relevance - when you're adding your artifact to any kind of remote repository, you need to use the deploy plugin (or release for non-trivial deployments).
Repository managers usually generate instructions on configuring your projects for deployment to a hosted repo.

maven defines a lifecycle (clean, compile, install, deploy...). There are default mappings when you execute "mvn install". So maven knows which plugins to execute for that maven goal.
The Introduction page gives a good overview what happens for each phase (goal) and what the default plugins are: https://maven.apache.org/guides/introduction/introduction-to-the-lifecycle.html
In your case: mvn install will copy the artifacts into the local maven repository to be shared by other projects you have locally.
If you want to share artifacts with other developers on other locations "mvn deploy" will copy the artifacts to the remote repository. Note you need to configure the distributionManagement section in the pom.xml to be able to do that.

The normal maven setup should look like this:
project -> local repository -> private remote repository -> public remote repository
Project: in the simplest case your project consists of source files and a configuration file (pom.xml). The project may depend on third party libraries like junit. The jar files of the libraries are not stored in your project directory, only the information which jars are needed.
mvn package
This command creates a jar out of your project an places it in the target/ folder of your project.
Local Repository: This is a maven repository stored locally on your machine. It normally resides in ~/.m2/repository/. Every dependency you are using in your project will be stored in this repository. On compiling your project, maven will use the jar files from this location.
mvn install
This command creates a jar file and copies it to your local repository: ~/.m2/repository/groupId/artifactId/version/project.jar. Now you can use this jar in different independent projects as a dependency, but only your machine.
Private Remote Repository: Most of the time this is a Nexus in your company network. This server allows to share the build project across developers. Your TeamCity server builds the jar and copies it to your nexus server. Beyond this the nexus server works like a proxy, e.g. A Developer needs junit-4.1.1.jar, so the server looks for it on public remote repositories and caches it.
mvn deploy
This command builds a jar and sends it to your nexus server ('to your private remote repository') After that every developer inside your company network can access the jar.
Public Remote Repository: These are repositories available on the internet which contain several jar files, e.g. maven.codehaus.org
Summary:
If you call mvn compile maven looks for the dependencies in your local repository. If maven can't find them, it will ask the (private/public) remote repository, and copy the files to the local repository.
You should not synchronize a local repository over network, since this type of repository is not targeted at such use and may break in some obscure way.

What you need is a mvn deploy - copies the final package to the remote repository for sharing with other developers and projects
mvn install you tried will just build and install the project in your local ~/.m2 repository. It will_not publish the artifacts to your nexus repository which you have configured.
Both install and deploy are valid build phase - meaning it executes all previous phases. Please refer to Maven docs below for more understanding.
From maven documentation:
the default Maven lifecycle has the following build phases (for a complete list of the build phases, refer to the Lifecycle Reference):
validate - validate the project is correct and all necessary information is available
compile - compile the source code of the project
test - test the compiled source code using a suitable unit testing framework. These tests should not require the code be packaged or deployed
package - take the compiled code and package it in its distributable format, such as a JAR.
integration-test - process and deploy the package if necessary into an environment where integration tests can be run
verify - run any checks to verify the package is valid and meets quality criteria
**install** - install the package into the local repository, for use as a dependency in other projects locally
**deploy** - done in an integration or release environment, copies the final package to the remote repository for sharing with other developers and projects.

Related

Multi-Module local jar dependencies - Jenkins Pipeline

I need to build a Java project on Maven. I am working on a multi-module Maven project that's built on the Jenkins Pipeline in the Nexus repository. I have a few libraries that are not available on the Nexus repository. I can't manually upload the libraries. I am building this project on a pipeline.
What I did:
I created a folder named jars in the project root of the Git hub repository and manually put all the jar files that are not available on Nexus. In the dependency, I referenced all these local jars as in the dependency parameters.
In the repositories, I gave the URL of the git hub repo of the jar folder. The Jenkins were not able to pick the libraries. I am getting the following error: dependency: dependency version - Build Error - Could not build for non-released dependencies and I am getting an error for all the jars that are in the jars folder. I tried putting the jars folder in src/main/resources but still getting the same error.
How can I reference this jar folder so that the Jenkins Pipeline can take it? I don't have control over the Jenkins / Scripts that are involved. I am a developer just building it on the Pipeline.
P.S: I don't have access to the internet at my company to post the POM or Build Failure errors.
Adding more details:
It's built on the Pipeline. There are two repositories: Nexus 2 and Nexus 3. The particular libraries are not available on Nexus 3 and pipeline takes the build only on Nexus 3.
We have raised a request to upload those libraries but it's not going to happen anytime soon. The Jenkins Pipelines takes it's files from the Github repository and builds the Java project using Maven. I don't have control to a pipeline or any of the scripts in Jenkins.
We downloaded all the libraries that are not available and put that in a folder in git hub. There are 4 cycles in the Pipeline. Github Cycle / Jenkins Cycle / Deployment Cycle / Release Cycle.
Github Cycle: In this cycle, it follows three stages. It takes the code from the code, builds it. It builds the snapshot and uploads it to Nexus repo. In these 2 stages, it was able to successfully build by taking the code from the GitHub and builds it and artifact generated. Third stage: It's really strange as in this stage, it again builds and build getting failed in this stage citing code for Non Released Dependencies for the jars that are uploaded in the git hub.
What might be the reason for this: When it can build in the first two stages of the Github cycle and getting failed in the third stage for Build Failure for non-released dependencies.
The pipeline is designed in such a way that it looks only on Nexus 3 and build during each phase of the cycle.
In the repositories, I gave the URL of the git hub repo of the jar
folder
That does not work because your lib folder is not a valid Maven repository.
How can I reference this jar folder so that the Jenkins Pipeline can
take it?
You have some options:
Set up custom Maven repository manager. You can use Nexus
Repository Manager or JFrog Artifactory or something else.
It will give you the greatest flexibility and allow to do a lot more
in the future. Downside is, you will need to have the infrastructure
to run this which usually comes with some sort of maintenance cost.
Install the bundles in Maven's local repo from the jar folder you already have. There are two ways you can do that:
Via script in Jenkins Pipeline that runs before your build and calls mvn install-file ... for each library in your jar folder. You can find the exact syntax for this command on Apache Maven Install Plugin site
By changing your build and calling the install-file goal of the maven-install-plugin in earlier build phase. I've personally
never done that but this answer suggests it's possible.
remove the files from the jar folder and create a wrapper project for each of them which does nothing but install the jar in
the local maven repository. Make sure those are the first modules to
run in your multi-module project.

Maven repository server for caching

I'm trying to understand some concepts about maven. This is the my scenario:
Almost every time I deploy a project, i.e Cloudstack I type:
mvn install
I got some failures like unable to connect to some repositories or that some tests just failed. I don't understand why some tests can fail if the code has been recently downloaded.
My idea is to create a local server repository so maven won't connect to remote servers but to a server that is in the same network with the packages that the application needs.
Is possible to do that? or does these problems are produced by other cause?
See Maven, Introduction to Repositories:
There are strictly only two types of repositories: local and remote. The local repository refers to a copy on your own installation that is a cache of the remote downloads, and also contains the temporary build artifacts that you have not yet released.
Remote repositories refer to any other type of repository, [...]. These repositories might be a truly remote repository set up by a third party to provide their artifacts for downloading [...]. Other "remote" repositories may be internal repositories set up on a file or HTTP server within your company, used to share private artifacts between development teams and for releases.
mvn install does not deploy your project's artifact (at least not in the sense of Maven's deploy, see Introduction to the Build Lifecycle). It does:
install the package into the local repository, for use as a dependency in other projects locally
whereas mvn deploy is:
done in an integration or release environment, copies the final package to the remote repository for sharing with other developers and projects
„unable to connect to some repositories“ and „some tests just failed“ are two different kind of errors. It's impossible to tell more without any relevant part(s) of the output of the build where these occurred.

How to install a Maven/Gradle project along with all its dependencies to a local repository?

I have a Gradle project that depends on several open-source projects up on Maven Central. I'd like to install the project – along with all its direct and transitive dependencies – to my local maven repository, so that I could later zip it all up and put it on offline machines.
How do I do it with Gradle/Maven?
mvn dependency:get plugin will fetch the artifact with all dependencies to the local repository.
I had also developed a plugin to install remote artifacts to a local machine.
If you want to later ZIP up your project w/ dependencies and move them to a different machine, you could try Maven's appassembler plugin. It collects all dependencies and creates a launcher, all in the target folder, ready for deployment.
But note, this, by default, creates a flat directory structure with all dependencies, it doesn't preserve the Maven format. It also has the option to create a repository.

Share Maven Dependencies with team members using Mercurial

I want to share all the External Jars currently being managed by MAVEN with my other team members. I am using Mercurial as my SCM and i am trying to figure what is the easiest way to commit my entire project (include libs) to a repository so that my team members can clone and get running without severe eclipse configuration?
Maven is there in order to help you retrieving libraries. So that, all you have to do is to commit all your files including the pom.xml (.hg should contains everything in target, and other unrelevant files)
Then your project members can pull the sources and run mvn eclipse:eclipse (see eclipse & maven.
And finally import the project in Eclipse.
That was is they need sources...
If they only need the jars, you must put in your infrastructure a company repo that will handle your deployment using mvn deploy. Some information there maven repo::Intro, take special care at the wagon you could use (ftp, ...)
This way, when you're done with your devel and you have pushed your code, you just have to deploy the jar on your repo.
Doing so, your project member'll have to run mvn -U eclipse:eclipse or any goal to update their local repository with your lastest deployed version.

Maven without Internet connection

I'm new to maven project.
I'm changing an ant project to maven project.
To install the 3rd party jar's in maven local repository, I used install command.
Its trying to download the resource jar.pom.
I don't have download access in my organization so the build failed for installtion.
After request i got the resouce jar and clean jar in my desktop(also i can get other necessary jar).
How to make maven to use these jar for the process and how to install the jar in local repository without internet acess.
I downloaded the jar and placed in local repository but it couldn't point the path and use those jars.
please let me know what steps i have follow to run maven install and other commands to build the project without internet access.
where should i placed the jar which i have downloaded by external way.
Please guide me for building and deploying the project.
Thanks in advance.
http://maven.40175.n5.nabble.com/Maven-installation-and-using-in-project-without-Internet-conncetion-tp4564443p4564443.html.
http://www.coderanch.com/t/544641/Jobs-Offered/careers/Maven-installation-project-without-Internet#2471141
I've posted same question in these link
You need an internet connection. Maven isn't initially self-sufficient. It needs to download a bunch of plugins along with their dependencies and the dependencies of your own project. And this really depends on what sort of settings you have for your projects. One set up will require one set of dependencies, another - a whole different one. You can't download artifacts from the Maven Central manually and then install them locally one by one. Simply put, that sounds stupid.
I understand that you're coming from the Ant world where Ant has everything it needs on the local file system. However, Maven relies on the fact that it will have a central repository (either Maven Central, or your own repository - Nexus, Artifactory, etc.) from which to download the plugins and dependencies it needs. There is no point in you migrating to Maven, unless you'll be allowed access to the Central Maven Repository.
Yes, indeed, you can run Maven offline and you can have Maven produce a local repository for you to use when you are in offline mode. However, what you're trying to do is against Maven's principles.
If your company won't allow access to Maven Central, just stick to Ant. Your effort will be a waste of your company's and, ultimately, your own time.
In fact the maven strenght is mainly in the internet accessible repositories and automatic dependency management. But it's possible to use this tool to build your project if you have all dependencies required for your project in your local repository. Then you may use -o option for offline mode and maven will not try to download updated artefact versions.
To get the artifacts into you local repository you have several options:
1) connect to the internet once and mvn build the project (this will download all required dependencies)
2) install dependencies as jar to the local repository manualy (using appropriate mvn command)
I think the questioner is looking for -o or --offline option for mvn. This is a command line option and can be provided while executing.
I think you can setup your repo correctly and execute the mvn goals once when you are connected to internet and use the -o option for later executions .
Hope this helps.
~Abhay
You can configure maven to run in offline mode. Add this entry to your settings.xml
<offline>true</offline>
See here for further information:
http://maven.apache.org/settings.html
Before you can use offline mode, you have to install all necessary third party jars to your local maven repository.
mvn install:install-file
-Dfile=filename.jar
-DgroupId=com.stackoverflow
-DartifactId=artifact
-Dversion=1.0.0
-Dpackaging=jar
-DcreateChecksum=true
-DgeneratePom=true
It's much easier to get those jars in your local repository using an internet connection and online mode.
It's possible to install these resource jars in your local maven repo using install-file. This will make the available to the build. You'll have to do this for each individually, but once that's done you won't have to do anything special.
To be clear, maven puts everything in your local repository, both the jar you're building with this project and the various library jars. Because your system cannot be connected to the internet to maven can populate the local repo with your libraries, you'll have to use this manual approach.
Edit: You should be able to run install-file anywhere. When you do, you'll need to provide the groupId, artifactId, version, and packaging using the command line options. If you already have a POM file for the library, you can provide that instead via -DpomFile=your-pom.xml.
This question has some useful info: How to manually install an artifact in Maven 2?

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