Jenkins is an opensource automation server written in Java which helps to automate the non-human part of the Software Development process with Continuous Integration and facilitating technical aspects of Continuous Delivery.

Jenkins is highly popular and captures almost 68% of market share and the second highest being TeamCity which enjoys almost 16% share.
Link: https://www.datanyze.com/market-share/ci/jenkins-market-share

I will be publishing series of articles on Jenkins, its usage, plugins etc.
Let’s start with Installation and few important configuration tweaks to support Jenkins in production.

Jenkins Installation

There are different ways by which we can install Jenkins:
Jenkins is available in 2 release modes:
1. Long Term Support (LTS) — This is the stable version and is recommended.
2. Weekly release — This is released weekly and includes bug fixes, features etc.

We will be using the LTS version in this article.

Pre-requisites : You need to have Java installed and should be available in the PATH.

1. Installation using Docker This is the preferred way as it doesn’t matter which Operation System you use. Execute the docker run command and that would set it up for you :-)

docker run --name jenkins -p 8080:8080 -p 50000:50000 -d jenkins/jenkins:lts

docker tail -f jenkins

2. Installation using Repository [ Ubuntu and Red Hat Enterprise Linux ]

For Ubuntu:

wget -q -O - https://pkg.jenkins.io/debian-stable/jenkins.io.key | sudo apt-key add -

echo "deb pkg.jenkins.io/debian-stable binary/" >> /etc/apt/sources.list

apt-get update && apt-get install -y jenkins

For Red Hat Enterprise Linux:

wget -O /etc/yum.repos.d/jenkins.repo https://pkg.jenkins.io/redhat/jenkins.repo

rpm --import https://pkg.jenkins.io/redhat/jenkins.io.key

yum install jenkins

3. Using WAR

wget -L http://mirrors.jenkins.io/war-stable/latest/jenkins.war

java -jar jenkins.war

Once installed using any of the above approaches, Jenkins should be up and running on port 8080.

http://localhost:8080

Jenkins Configuration

Jenkins configuration file is located at : /etc/default/jenkins

1. Increase the heap size : Edit the /etc/default/jenkins and the below configuration-
   JAVA_ARGS="-Xmx2048m" #Where 2048m is 2GB of heap. Default is 256MB.
2. Configure https:

# Create key and certificate. Provide information wherever asked.
openssl req -newkey rsa:2048 -nodes -keyout jenkins.key -x509 -days 700 -out jenkins.crt

#Below command would ask you for password. Remember the same as that will be used during the configuration.

openssl pkcs12 -inkey jenkins.key -in jenkins.crt -export -out keys.pkcs12

keytool -importkeystore -srckeystore keys.pkcs12 -srcstoretype pkcs12 -destkeystore /var/lib/jenkins/jenkins.jks

Once the certificates are generated , configure the same in the /etc/default/jenkins file.

JENKINS_ARGS="--webroot=/var/cache/$NAME/war --httpPort=-1 --httpsPort=8443 --httpsKeyStore=/var/lib/jenkins/jenkins.jks --httpsKeyStorePassword="

Note: httpPort=-1 would disable http. If you wish to have both http and https , then provide the desired port.

Once the above configuration is done, restart jenkins to reflect the change.
Now, you will be able to access jenkins via https using the below link

localhost:8443

Hope you enjoyed installing and configuring Jenkins !!!!