Nexus

This page explains how to setup and configure NEXUS Maven repositories.

Requirements

a) You need to setup Maven

b) Create user / group

# Create group
addgroup --system "nexus"
 
# Create Nexus user (home directory must be Nexus)
adduser --home /opt/nexus --disabled-login --disabled-password nexus

c) You need to create a root folder to host all the artifacts

mkdir -p /home/nexus
chmod -R 777 /home/nexus
chown -R nexus:nexus /home/nexus

Installation

Download Nexus OSS as Nexus Open-Source Server - take the ZIP format

• http://www.sonatype.org/nexus/go/

cd /opt
wget http://www.sonatype.org/downloads/nexus-latest-bundle.tar.gz
tar xzvf nexus-latest-bundle.tar.gz
rm nexus-latest-bundle.tar.gz
ln -s /opt/nexus-2.11.4-01/ /opt/nexus

Set rights

chown -R nexus:nexus /opt/nexus
chown -R nexus:nexus /opt/nexus-2.11.4-01

Configuration

Set nexus parameters

Adjust the port number and root context path, if required

vim /opt/nexus/conf/nexus.properties

Set:

application-port=9081
application-host=127.0.0.1
nexus-webapp-context-path=/nexus

## Nexus section
## nexus-work ==>> folders where the artifacts are going to be saved. You must choose a folder with a lot of disk!
nexus-work=/home/nexus
runtime=${bundleBasedir}/nexus/WEB-INF

Log symlink

ln -s /opt/nexus/logs/wrapper.log /var/log/nexus.log

Set Nexus user and rights

vim /opt/nexus/bin/nexus

# Set the correct home
NEXUS_HOME="/opt/nexus"

#uncomment and adjust
RUN_AS_USER="nexus"
#The PID directory must be a directory where you the runtime user can Read/Write
PIDDIR="/opt/nexus"

ERROR Fix

If you encounter the Failed to start Nexus OSS error, then you need to:

chown -R nexus:nexus /opt/sonatype-work

Run Nexus from anywhere

Set the NEXUS_HOME into the start script. Without it you cannot run Nexus as a service!

ln -s /opt/nexus/bin/nexus /usr/bin/nexus
ln -s /opt/nexus/bin/nexus /etc/init.d/nexus

vim /opt/nexus/bin/nexus

Congratulation! Now you’r Nexus installation is available on http://localhost:8081/nexus/. The default user and password are “admin” and “admin123“. Basic configuration of the maven clients

Login as admin, locate predefined repositories. All repositories of type “proxy” need to change “Download Remote Indexes” property to true in the configuration tab.

As you see there are several types of repositories.

   proxy – acts as proxy for external repository.
   hosted – repository that managed artifact produced by you
   virtual – kind of adapter for e.g transforming maven1 to maven 2 format.
   group – maybe not a repository in sonatyp’s terminology but behaves like one. A group groups several repositories to one exposing result as single URI.

Per default there is a group “public” present. This group includes all the needed stuff, we just need to tell our maven clients to use this group. Maybe the easiest and flexiblest way to do so, is to use a mirror in settings.xml of your local maven. <mirrors>

 <mirror>
   <id>nexus</id>
   <mirrorOf>*</mirrorOf>
  <url>http://YOR_NEXUS_HOST:8081/nexus/content/groups/public</url>
 </mirror>

</mirrors>

Then we use a power of Maven Profiles and define new repositories they are magically (consider “*” in the mirror declaration) maps to the mirror. <profile>

    <id>nexus</id>
    <repositories>
      <repository>
        <id>central</id>
        <url>http://central</url>
        <releases><enabled>true</enabled></releases>
        <snapshots><enabled>true</enabled></snapshots>
      </repository>
    </repositories>
   <pluginRepositories>
      <pluginRepository>
        <id>central</id>
        <url>http://central</url>
        <releases><enabled>true</enabled></releases>
        <snapshots><enabled>true</enabled></snapshots>
      </pluginRepository>
    </pluginRepositories>
  </profile>

Do not forgete to activate thins new profile <activeProfiles>

   <activeProfile>nexus</activeProfile>

</activeProfiles>

Now your maven client knows only your nexus and everything it needs and how it gets it, should be controlled by nexus.

References

• http://alexander.holbreich.org/2012/10/sonatype-nexus-setup/