This is just a basic introduction to the CI/CD tool Jenkins.

CI/CD stands for Continuous Integration and Continuous Deployment which comes under DevOps.

So, whenever we make changes in our code then Jenkins can automatically build and test it. With this it will be helpful to find any kind of bugs of failures in the application.

Extensive documentation can be found here -> https://www.jenkins.io/doc/book/installing/

For Debian based distributions

curl -fsSL https://pkg.jenkins.io/debian/jenkins.io.key | sudo tee \
  /usr/share/keyrings/jenkins-keyring.asc > /dev/null
echo deb [signed-by=/usr/share/keyrings/jenkins-keyring.asc] \
  https://pkg.jenkins.io/debian binary/ | sudo tee \
  /etc/apt/sources.list.d/jenkins.list > /dev/null
sudo apt update
sudo apt install jenkins

For Fedora

sudo wget -O /etc/yum.repos.d/jenkins.repo \
    https://pkg.jenkins.io/redhat-stable/jenkins.repo
sudo rpm --import https://pkg.jenkins.io/redhat-stable/jenkins.io.key
sudo dnf upgrade
# Add required dependencies for the jenkins package
sudo dnf install java-11-openjdk
sudo dnf install jenkins

For Arch based distributions

sudo pacman -Syy jenkins

If you are using a non-systemd init system then also install jenkins-runit or jenkins-openrc , according to your init system.

For systemd:

     see the official docs (or just google it, systemd is quite famous).

For Runit:

    1. create a symlink

         sudo ln -s /etc/sv/jenkins /var/service/jenkins

        or

         sudo ln -s /etc/runti/sv/jenkins /run/runit/service

    this should start the jenkins service immediately, if not then

    2. start the service

         sudo sv up jenkins

          or

        sudo sv start jenkins

1. first get the ip address of your machine

            For linux, run ifconfig command, and see the 'inet' line for ip address.

    2. paste this https://<your_ip>:8080 in the browser.    (the port number can be changed later)

    3. then the webapp starts

    4. cat out following file and paste its contents in the box

             cat /var/lib/jenkins/secrets/initialAdminPassword

There you Go :)