nexus-installation6.sh

#!/bin/bash
# Install and start nexus as a service 
# This script works on RHEL 7 & 8 OS 
# Your server must have atleast 4GB of RAM
# become the root / admin user via: sudo su -
#1. Create nexus user to manage the nexus
# As a good security practice, Nexus is not advised to run nexus service as a root user, so create a new user called nexus and grant sudo access to manage nexus services as follows.

useradd nexus

#4 Give sudo access to nexus user

sudo echo "nexus ALL=(ALL) NOPASSWD:ALL" | sudo tee /etc/sudoers.d/nexus
sudo su - sonar

cd /opt

# 1.Install prerequisit: JAVA, git, unzip

sudo yum install wget git nano unzip -y
sudo yum install java-11-openjdk-devel java-1.8.0-openjdk-devel -y


# 2. Download nexus software and extract it (unzip)

sudo wget http://download.sonatype.com/nexus/3/nexus-3.15.2-01-unix.tar.gz 

sudo tar -zxvf nexus-3.15.2-01-unix.tar.gz
mv /opt/nexus-3.15.2-01 /opt/nexus


#5 Change the owner and group permissions to /opt/nexus and /opt/sonatype-work directories.


sudo chown -R nexus:nexus /opt/nexus
sudo chown -R nexus:nexus /opt/sonatype-work
sudo chmod -R 775 /opt/nexus
sudo chmod -R 775 /opt/sonatype-work

#6 Open /opt/nexus/bin/nexus.rc file and  uncomment run_as_user parameter and set as nexus user.

vi /opt/nexus/bin/nexus.rc
run_as_user="nexus"

#7 CONFIGURE NEXUS TO RUN AS A SERVICE 

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

#9 Enable and start the nexus services
sudo systemctl enable nexus
sudo systemctl start nexus
sudo systemctl status nexus
echo "end of nexus installation"

=====================
access nexus on the browser
34.229.62.93:8081
userName  --- ADMIN
Password   ADMIN123

<<Troubleshooting
---------------------
nexus service is not starting?

a)make sure  to change the ownership and group to /opt/nexus and /opt/sonatype-work directories and permissions (775) for nexus user.
b)make sure you are trying to start nexus service AS nexus user.
c)check java is installed or not using java -version command.
d) check the nexus.log file which is availabe in  /opt/sonatype-work/nexus3/log  directory.

Unable to access nexus URL?
-------------------------------------
a)make sure port 8081 is opened in security groups in AWS ec2 instance.

Troubleshooting