Nexus_Configuration.txt

Nexus-Storing artifacts in Nexus after build
Problem Statement: In the document below, We will be storing our build artifacts in the Nexus.
Install Nexus on Ubuntu machine
1. Launch a Ubuntu instance, instance type as t3.medium(which has minimum 4 cpu's) and root storage as 20GB.
2. Security group as ssh- my ip and Custom TCP-8081 Open to the world.
3. update the system packages
4.
sudo apt-get update
Install OpenJDK 1.8 on Ubuntu 20.04 LTS
sudo apt install openjdk-8-jre-headless
Download Nexus Repository Manager setup on Ubuntu 20.04 LTS
Download the latest Nexus Repository Manager Setup from official nexus page.
Navigate to /opt directory
cd /opt
Download the SonaType Nexus on Ubuntu using wget
sudo wget https://download.sonatype.com/nexus/3/latest-unix.tar.gz
#3: Install Nexus Repository on Ubuntu 20.04 LTS
Extract the Nexus repository setup in /opt directory
sudo tar -zxvf latest-unix.tar.gz
Rename the extracted Nexus setup folder to nexus
ls

sudo mv /opt/nexus-3.36.0-01 /opt/nexus
As security practice, not to run nexus service using root user, so lets create new user named nexus to run nexus service
sudo adduser nexus
Type and Retype a password to it. Enter the details(optional)
To set no password for nexus user open the visudo file in ubuntu

Nexus-Storing artifacts in Nexus after build 2
sudo visudo
Add below line into it , save and exit
nexus ALL=(ALL) NOPASSWD: ALL
Give permission to nexus files and nexus directory to nexus user
sudo chown -R nexus:nexus /opt/nexus

sudo chown -R nexus:nexus /opt/sonatype-work
To run nexus as service at boot time, open /opt/nexus/bin/nexus.rc file, uncomment it and add nexus user as shown below
sudo nano /opt/nexus/bin/nexus.rc

run_as_user="nexus"
To Increase the nexus JVM heap size, open the /opt/nexus/bin/nexus.vmoptions file, you can modify the size as shown below
In the below settings, the directory is changed from ../sonatype-work to ./sonatype-work
-Xms1024m
-Xmx1024m
-XX:MaxDirectMemorySize=1024m
-XX:LogFile=./sonatype-work/nexus3/log/jvm.log
-XX:-OmitStackTraceInFastThrow
-Djava.net.preferIPv4Stack=true
-Dkaraf.home=.
-Dkaraf.base=.
-Dkaraf.etc=etc/karaf
-Djava.util.logging.config.file=/etc/karaf/java.util.logging.properties
-Dkaraf.data=./sonatype-work/nexus3
-Dkaraf.log=./sonatype-work/nexus3/log
-Djava.io.tmpdir=./sonatype-work/nexus3/tmp
#4: Run Nexus as a service using Systemd
To run nexus as service using Systemd
sudo nano /etc/systemd/system/nexus.service
paste the below lines into it.
[Unit]
Description=nexus service
After=network.target
[Service]
Type=forking
LimitNOFILE=65536
ExecStart=/opt/nexus/bin/nexus start
ExecStop=/opt/nexus/bin/nexus stop
User=nexus
Restart=on-abort
[Install]
WantedBy=multi-user.target

Nexus-Storing artifacts in Nexus after build 3
To start nexus service using systemctl
sudo systemctl start nexus
To enable nexus service at system startup
sudo systemctl enable nexus
To check nexus service status
sudo systemctl status nexus
To stop Nexus service
sudo systemctl stop nexus
if the nexus service is not started, you can the nexus logs using below command
tail -f /opt/sonatype-work/nexus3/log/nexus.log
We have covered How to Install Nexus Repository on Ubuntu 20.04 LTS.
#5: Access Nexus Repository Web Interface
To access Nexus repository web interface , open your favorite browser
if you are running UFW firewall on Ubuntu, open the firewall port 8081 using below command
sudo ufw allow 8081/tcp

http://server_IP:8081
you will see below default nexus page

Nexus-Storing artifacts in Nexus after build 4
To login to Nexus, click on Sign In, default username is admin
To find default password run the below command
cat /opt/nexus/sonatype-work/nexus3/admin.password
copy the default nexus password and login, you can reset the password once logged in to nexus
Below nexus setup wizard will show
Change the password
configure Anonymous Access

Nexus-Storing artifacts in Nexus after build 5
Next and click on Finish.

Create a Repository
Click on the Settings button
Click on Repositories > create a new repository > select maven2(hosted)
give it a name.
Version policy - select "Mixed"
Layout Policy - permissive
In Hosted - Deployment Policy - Allow redeploy
Click on Create Repository

Create a Local User
In security tab, Select Users -
id - jenkins-user
firstname - jenkins
lastname - user
email- provide id
password - 12345
retype password - 12345
status - active
In availables - double click on nx-admin to select
Click on create local user