How to install Apache Maven on Redhat Enterprise Linux Instance?

Here are the steps for installing Apache Maven on RHEL:
Make sure you install Java first by following below steps:

sudo yum -y install wget
sudo wget --no-check-certificate --no-cookies --header 'Cookie: oraclelicense=accept-securebackup-cookie' 'http://download.oracle.com/otn-pub/java/jdk/8u141-b15/336fa29ff2bb4ef291e347e091f7f4a7/jdk-8u141-linux-x64.rpm'
sudo rpm -i jdk-8u141-linux-x64.rpm

Now steps for installing Apache Maven:
sudo wget http://repos.fedorapeople.org/repos/dchen/apache-maven/epel-apache-maven.repo -O /etc/yum.repos.d/epel-apache-maven.repo
sudo sed -i s/\$releasever/6/g /etc/yum.repos.d/epel-apache-maven.repo
sudo yum install -y apache-maven
mvn --version

the above command should print the below message:

Apache Maven 3.5.2 (138edd61fd100ec658bfa2d307c43b76940a5d7d; 2017-10-18T07:58:13Z)
Maven home: /usr/share/apache-maven
Java version: 1.7.0_181, vendor: Oracle Corporation
Java home: /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.181-2.6.14.8.el7_5.x86_64/jre
Default locale: en_US, platform encoding: UTF-8
OS name: "linux", version: "3.10.0-862.el7.x86_64", arch: "amd64", family: "unix"

How to change default port number in Sonatype Nexus 2? - Change default port number in SonaType Nexus 2

The default port number for Sonatype Nexus is 8081. It can be changed though.
If you would like to change it, modify in below location:
$install-dir/etc/org.sonatype.nexus.cfg file
application-port=8082

Click here to see steps for how to install Nexus on Redhat.
Click here to see steps for how to install Nexus on Ubuntu.

How to install Sonarqube on Redhat enterprise Linux - Install Sonarqube on Redhat enterprise Linux (RHEL)

SonarQube is popular static code analysis tool. It is Java based tool. Here are the steps for installing Sonarqube.

first you need to install a database as SonarQube uses database to store code quality report. We can use MySQL, Postgres, Oracle or MSSQL. Here are the steps for setting up SonarQube using MySQL database :

sudo yum update -y

sudo yum install wget -y

MySQL installation steps:

sudo wget http://repo.mysql.com/mysql-community-release-el7-5.noarch.rpm  

sudo rpm -ivh mysql-community-release-el7-5.noarch.rpm

sudo yum install mysql-server -y

Start MySQL service

sudo systemctl start mysqld

sudo mysql_secure_installation

enter n as we will not be setting any admin password for user root.

Would you like to setup VALIDATE PASSWORD component?
type n

now set up password for root user

Remove anonymous users?
type y
for Disallow root login remotely?
type y
for Remove test database and access to it?
type y
for Reload privileges tables
type y

Setup Sonarqube user and password

mysql -u root -p

SHOW GLOBAL VARIABLES LIKE 'storage_engine';

CREATE USER 'sonar'@'localhost' IDENTIFIED BY 'password';

CREATE DATABASE sonar;

GRANT ALL PRIVILEGES ON sonar.* TO 'sonar'@'localhost';

now type exit to come out of MySQL.

Sonarqube web server installation steps:

Start with java installation.

sudo wget --no-check-certificate --no-cookies --header 'Cookie: oraclelicense=accept-securebackup-cookie' 'http://download.oracle.com/otn-pub/java/jdk/8u141-b15/336fa29ff2bb4ef291e347e091f7f4a7/jdk-8u141-linux-x64.rpm'

sudo rpm -i jdk-8u141-linux-x64.rpm

now type java -version to make sure Java 8 is installed.

Download SonarQube

cd /opt 

sudo wget https://binaries.sonarsource.com/Distribution/sonarqube/sonarqube-6.7.6.zip

sudo yum install unzip -y

sudo unzip sonarqube-6.7.6.zip

sudo mv sonarqube-6.7.6 sonarqube

Modify Sonar Conf file

sudo vi /opt/sonarqube/conf/sonar.properties

uncomment the below lines by removing #:

sonar.jdbc.username=sonar

sonar.jdbc.password=password

sonar.jdbc.url=jdbc:mysql://localhost:3306/sonar?useUnicode=true&characterEncoding=utf8&rewriteBatchedStatements=true&useConfigs=maxPerformance

sonar.web.host=0.0.0.0

sonar.web.javaOpts=-Xmx512m -Xms256m -XX:+HeapDumpOnOutOfMemoryError

sonar.ce.javaOpts=-Xmx512m -Xms256m -XX:+HeapDumpOnOutOfMemoryError

Run Sonarqube as sonar user
create a user called sonar by executing below command:
sudo useradd sonar

sudo chown -R sonar:sonar /opt/sonarqube

Edit the sonar.sh start script and change the #RUN_AS_USER to be RUN_AS_USER=sonar

sudo vi /opt/sonarqube/bin/linux-x86-64/sonar.sh

Change 
RUN_AS_USER=sonar

now start the server 

sudo sh /opt/sonarqube/bin/linux-x86-64/sonar.sh start

for any issues, look at logs at 

tail -f /opt/sonarqube/logs/sonar.log

Verify by going to browser http://hostname:9000

 

Docker installation on Ubuntu 16.0.4 server

Docker can be installed on Ubuntu 16.0.4 by following below steps:
 
sudo curl -fsSLhttps://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"

sudo apt-get update

sudo apt-cache policy docker-ce

sudo apt-get install -y docker-ce

sudo systemctl status docker

ps -ef | grep docker

docker –version

docker run hello-world