David

Posted on May 24, 2021

🌟Install Jenkins in Windows Subsystem for Linux (WSL2)

#jenkins #wsl #wsl2 #cicd

Jenkins

Jenkins is one of the most popular tools DevOps tools, originally designed with one purpose in mind: be a great build automation server. It’s free and open-source, built for developers, and has lots and lots of plugins that you can configure to build anything.

Although Jenkins can be deployed to lots of public clouds like AWS, GCP or Azure, running a local Jenkins server still has its own advantages and values. Speeds and easy for experimentation are just two of the most important ones.

Windows Subsystem for Linux

The Windows Subsystem for Linux (WSL) lets developers run a GNU/Linux environment -- including most command-line tools, utilities, and applications -- directly on Windows, unmodified, without the overhead of a traditional virtual machine or dual-boot setup.

WSL 2 is a new version of the Windows Subsystem for Linux architecture that powers the Windows Subsystem for Linux to run ELF64 Linux binaries on Windows. Its primary goals are to increase file system performance, as well as adding full system call compatibility.

Install WSL2 on Windows

For the full instructions to install WSL2 on windows, refer to this link or this one

Mix together: Install Jenkins in Windows Subsystem for Linux

This blog will focus on putting all the nice stuffs together: Windows + Ubuntu + Jenkins.

Open a terminal in Windows

Open a new Ubuntu terminal (I am using Windows Terminal, but you can use whatever terminal tools like blow excellent candidates)

Update Ubuntu in WSL2

Below here are the quick scripts for updating Ubuntu in WSL2:



sudo -s
apt-get update
apt-get -y install apt-transport-https ca-certificates curl gnupg-agent software-properties-common
apt-get update

Install Java and Jenkins in WSL2



sudo apt install openjdk-8-jdk           # choose this or next line
sudo apt install openjdk-11-jre-headless # or Install Java 11 JDK/JRE
sudo apt install Jenkins

You will get an error like below:

To solve this, run the below script:



wget -q -O - https://pkg.jenkins.io/debian-stable/jenkins.io.key | sudo apt-key add
sudo bash -c 'echo deb https://pkg.jenkins.io/debian-stable binary/ > /etc/apt/sources.list.d/jenkins.list'
sudo apt update
sudo apt-get install jenkins

With this, ~ 68MB Jenkins package will be downloaded, it will take a while depending on the internet speeds.

Update Firewall to enable Jenkins service



sudo ufw enable
sudo ufw allow 8080 # whatever port number you like

Check the status of your port:



sudo ufw status

Run Jenkins server



sudo service jenkins start

Install Jenkins from a browser

Navigate to your host browser, and type:



http://localhost:8080/

You will see the screen as below:

where you will be prompted to provide an initial password to unlock Jenkins.

Follow up the screen instructions and in the terminal, type below:



sudo cat /var/lib/jenkins/secrets/initialAdminPassword

Copy the password you retrieved to clipboard
Return to the host browser window, and paste the password therein
Click "Continue" button!

Follow the screen instructions to create an account. Hooray!

Top comments (8)

Francis Vila • Dec 21 '21

Everything works up to sudo ufw enable .
This triggers an error starting with

ERROR: problem running ufw-init
modprobe: ERROR: ../libkmod/libkmod.c:586 kmod_search_moddep() could not open moddep file '/lib/modules/4.4.0-19041-Microsoft/modules.dep.bin'

Looking up the errors does not give encouraging results. It appears ufw does not function with WSL.
This link: askubuntu.com/questions/1100739/i-... even concludes (about ufw on WSL) that "Some tools are really not portable to different platforms".

I read a stackoverflow post (stackoverflow.com/questions/660185... ) saying "Just let the Windows Firewall do its job if you are concerned about external access to the Nginx. " But no clues as to how to do this.

I'm using Ubuntu 18.04

alogan5201 • Jul 13 '23

I had the same issue and this resolved it:
Run:
sudo nano /usr/lib/python3/dist-packages/ufw/util.py

Replace under_ssh function with

def under_ssh(pid=None):
'''Try to determine if we are being run from an ssh session'''
if pid is None:
pid = str(os.getpid())

ppid = None
try:
    name = "/proc/%s/stat" % pid
    ppid = open(name).readlines()[0].split(')')[1].split()[1]
except IOError:
    err_msg = _("Couldn't find parent pid for '%s'") % pid
    raise ValueError(err_msg)
except IndexError: # Add this block
    return False

if ppid == '1':
    return False

name = "/proc/%s/cmdline" % ppid
try:
    cmdline = open(name).readline().strip().split('\x00')
except IOError:
    return False

for i in cmdline:
    if re.search('sshd', i):
        return True

return under_ssh(ppid)