Install SonaType Nexus 3 on Ubuntu 18.0.4 - How to configure SonaType Nexus 3 on Ubuntu - Install Nexus on Ubuntu

SonaType Nexus3 is one of the popular binary repository managers, used for storing build artifacts such as Jars,WARs, EARs. It is Java based web application. 

Pre-requistes
Please create a new Ubuntu 18.0.4 EC2 instance with small type in AWS cloud. You would need at least 2 GB RAM.

Let us see how to configure Nexus 3 on Ubuntu 18.0.4.

How to setup SonaType Nexus3 on Ubuntu:

Java 8 installation
sudo apt update && sudo apt install openjdk-8-jre-headless -y

Note: Nexus is not compatible with Java 11 in Ubuntu 18.0.4. So we need to install Java 8.
java -version

Execute the below commands -  navigate to /opt directory by changing directory:
cd /opt

Download Nexus
sudo wget https://download.sonatype.com/nexus/3/nexus-3.22.0-02-unix.tar.gz

Extract Nexus files

sudo tar -xvf nexus-3.22.0-02-unix.tar.gz
sudo mv nexus-3.22.0-02 nexus

Create a user called Nexus
sudo adduser nexus

give some password may be as admin, but do remember.

Keep entering enter for all other values and press y to confirm the entries.

Give permission to Nexus user

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

sudo vi /opt/nexus/bin/nexus.rc

change run_as_user="nexus"
 



Modify memory settings
sudo vi /opt/nexus/bin/nexus.vmoptions

Add all the below changes the file with below yellow highlighted entry:

-Xms512M

-Xmx512M
-XX:MaxDirectMemorySize=512m

Configure Nexus to run as a service
sudo vi /etc/systemd/system/nexus.service
Copy the below content highlighted in green color.

[Unit]
Description=nexus service
After=network.target

[Service]
Type=forking
LimitNOFILE=65536
User=nexus
Group=nexus
ExecStart=/opt/nexus/bin/nexus start
ExecStop=/opt/nexus/bin/nexus stop
User=nexus
Restart=on-abort

[Install]
WantedBy=multi-user.target

Now Start Nexus

sudo systemctl enable nexus

sudo systemctl start nexus 

sudo systemctl status nexus

if it says stopped, review the steps above and you can troubleshoot by looking into Nexus logs by executing below command:

tail -f /opt/sonatype-work/nexus3/log/nexus.log

Press control C to come out of the above window.
It should say Started Sonatype Nexus OSS 3.22.0-02.  If you Nexus stopped, review the steps above.

Once Nexus is successfully installed, you can access it in the browser by 

URL - http://public_dns_name:8081

Now click on Sign in, enter admin as user name and password by executing below cat command.

cat /opt/sonatype-work/nexus3/admin.password
Now change admin password as admin123

enable anonymous access

Click Finish.

Sign in with user name/password is admin/admin123

you should see the home page of Nexus.

Please follow steps for integrating Nexus with Jenkins

http://www.cidevops.com/2018/06/jenkins-nexus-integration-how-to.html