[maven] Adding maven nexus repo to my pom.xml

I have installed nexus on my local machine. I want my pom file to point to this repo. How can I add my custom repository to my pom.xml file?

This question is related to maven

The answer is


From Maven - Settings Reference

The repositories for download and deployment are defined by the repositories and distributionManagement elements of the POM. However, certain settings such as username and password should not be distributed along with the pom.xml. This type of information should exist on the build server in the settings.xml.

<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
                  http://maven.apache.org/xsd/settings-1.0.0.xsd">
  ...
  <servers>
    <server>
      <id>server001</id>
      <username>my_login</username>
      <password>my_password</password>
      <privateKey>${user.home}/.ssh/id_dsa</privateKey>
      <passphrase>some_passphrase</passphrase>
      <filePermissions>664</filePermissions>
      <directoryPermissions>775</directoryPermissions>
      <configuration></configuration>
    </server>
  </servers>
  ...
</settings>

id: This is the ID of the server (not of the user to login as) that matches the id element of the repository/mirror that Maven tries to connect to.

username, password: These elements appear as a pair denoting the login and password required to authenticate to this server.

privateKey, passphrase: Like the previous two elements, this pair specifies a path to a private key (default is ${user.home}/.ssh/id_dsa) and a passphrase, if required. The passphrase and password elements may be externalized in the future, but for now they must be set plain-text in the settings.xml file.

filePermissions, directoryPermissions: When a repository file or directory is created on deployment, these are the permissions to use. The legal values of each is a three digit number corrosponding to *nix file permissions, ie. 664, or 775.

Note: If you use a private key to login to the server, make sure you omit the element. Otherwise, the key will be ignored.

All you should need is the id, username and password

The id and URL should be defined in your pom.xml like this:

<repositories>
    ...
    <repository>
        <id>acme-nexus-releases</id>
        <name>acme nexus</name>
        <url>https://nexus.acme.net/content/repositories/releases</url>
    </repository>
    ...
</repositories>

If you need a username and password to your server, you should encrypt it. Maven Password Encryption


First of all I can highly recommend reading the Nexus book. It will explain the benefits of using a Maven repository manager.

There is a section on how to configure your Maven build to use Nexus:

This leads me to question why you altering your POM file? I suspect what you really want to do is setup Nexus as a remote repository mirror. This is done in your Maven settings file.

The following tells Maven use Nexus as your default repository (Instead of Maven Central)

<settings>
  ..
  ..
  <mirrors>
    <mirror>
      <id>nexus</id>
      <url>http://localhost:8081/nexus/content/groups/public</url>
      <mirrorOf>central</mirrorOf>
    </mirror>
  </mirrors>

This is desired behaviour since your Nexus repository is configured to cache artifacts retrieved from Central (which is good for build performance).

Note:

  • The "public" repository group could include other repositories proxied by your Nexus instance (Not just Maven Central). You probabily want this behaviour, as it centralizes all repository management. It just makes your build less portable for people outside of your organization.

From maven setting reference, you can not put your username/password in a pom.xml

The repositories for download and deployment are defined by the repositories and distributionManagement elements of the POM. However, certain settings such as username and password should not be distributed along with the pom.xml. This type of information should exist on the build server in the settings.xml.

You can first add a repository in your pom and then add the username/password in the $MAVEN_HOME/conf/settings.xml:

  <servers>
    <server>
        <id>my-internal-site</id>
        <username>yourUsername</username>
        <password>yourPassword</password>
    </server>
  </servers>

If you don't want or you cannot modify the settings.xml file, you can create a new one in your root project, and call maven passing it as a parameter with the -s parameter:

$ mvn COMMAND ... -s settings.xml

From the Apache Maven site

<project>
  ...
  <repositories>
    <repository>
      <id>my-internal-site</id>
      <url>http://myserver/repo</url>
    </repository>
  </repositories>
  ...
</project>

"The repositories for download and deployment are defined by the repositories and distributionManagement elements of the POM. However, certain settings such as username and password should not be distributed along with the pom.xml. This type of information should exist on the build server in the settings.xml." - Apache Maven site - settings reference

<servers>
    <server>
        <id>server001</id>
        <username>my_login</username>
        <password>my_password</password>
        <privateKey>${user.home}/.ssh/id_dsa</privateKey>
        <passphrase>some_passphrase</passphrase>
        <filePermissions>664</filePermissions>
        <directoryPermissions>775</directoryPermissions>
        <configuration></configuration>
    </server>
</servers>

It seems the answers here do not support an enterprise use case where a Nexus server has multiple users and has project-based isolation (protection) based on user id ALONG with using an automated build (CI) system like Jenkins. You would not be able to create a settings.xml file to satisfy the different user ids needed for different projects. I am not sure how to solve this, except by opening Nexus up to anonymous access for reading repositories, unless the projects could store a project-specific generic user id in their pom.xml.