How do you run a test in Jenkins pipeline?

Test automation is widely considered to be a cornerstone of agile development. If you want to release fast, even daily, with reasonable quality, you have to move to automated testing. On the other hand, giving less importance to testing can result in customer dissatisfaction and a delayed product. However, automating the testing process is a bit more difficult than automating the build, release, and deployment processes. It usually takes a lot of effort to automate nearly all the test cases used in an application. It is an activity that matures over time. It is not always possible to automate all the testing. But, the idea is to automate whatever testing is possible.

I have a solution that works well for me. It consists of a local jenkins running in docker and a git web hook to trigger the pipeline in the local jenkins on every commit. You no longer need to push to your github or bitbucket repository to test the pipeline.

This has only been tested in a linux environment.

It is fairly simple to make this work although this instruction is a tad long. Most steps are there.

• Docker installed and working. This is not part of this instruction.
• A Jenkins running in docker locally. Explained how below.
  • The proper rights (ssh access key) for your local Jenkins docker user to pull from your local git repo. Explained how below.
  • A Jenkins pipeline project that pulls from your local git repository. Explained below.
  • A git user in your local Jenkins with minimal rights. Explained below.
• A git project with a post-commit web hook that triggers the pipeline project. Explained below.

Jenkins Docker

Create a file called Dockerfile in place of your choosing. I'm placing it in

$ docker build -t local_jenkins /opt/docker/jenkins/

FROM jenkins/jenkins:lts
USER root
RUN apt-get -y update && apt-get -y upgrade
# Your needed installations goes here
USER jenkins

Build the local_jenkins image

This you will need to do only once or after you have added something to the Dockerfile.

$ docker build -t local_jenkins /opt/docker/jenkins/

Start and restart local_jenkins

From time to time you want to start and restart jenkins easily. E.g. after a reboot of your machine. For this I made an alias that I put in

$ docker build -t local_jenkins /opt/docker/jenkins/

$ echo "alias localjenkinsrestart='docker stop jenkins;docker rm jenkins;docker run --name jenkins -i -d -p 8787:8080 -p 50000:50000 -v /opt/docker/jenkins/jenkins_home:/var/jenkins_home:rw local_jenkins'" >> ~/.bash_aliases
$ source .bash_aliases  # To make it work

Make sure the

$ docker build -t local_jenkins /opt/docker/jenkins/

To start or restart your jenkins just type:

$ localjenkinsrestart

Everything you do in your local jenkins will be stored in the folder /opt/docker/jenkins/jenkins_home and preserved between restarts.

Create a ssh access key in your docker jenkins

This is a very important part for this to work. First we start the docker container and create a bash shell to it:

$ localjenkinsrestart
$ docker exec -it jenkins /bin/bash

You have now entered into the docker container, this you can see by something like

$ docker build -t local_jenkins /opt/docker/jenkins/

Create the key

jenkins@e7b23bad10aa:/$ ssh-keygen

Press enter on all questions until you get the prompt back

Copy the key to your computer. From within the docker container your computer is 172.17.0.1 should you wonder.

jenkins@e7b23bad10aa:/$ ssh-copy-id [email protected]

user = your username and 172.17.0.1 is the ip address to your computer from within the docker container.

You will have to type your password at this point.

Now lets try to complete the loop by ssh-ing to your computer from within the docker container.

jenkins@e7b23bad10aa:/$ ssh [email protected]

This time you should not need to enter you password. If you do, something went wrong and you have to try again.

You will now be in your computers home folder. Try

$ docker build -t local_jenkins /opt/docker/jenkins/

Do not stop here since we have a chain of ssh shells that we need to get out of.

$ exit
jenkins@e7b23bad10aa:/$ exit

Right! Now we are back and ready to continue.

Install your Jenkins

You will find your local Jenkins in your browser at http://localhost:8787.

First time you point your browser to your local Jenkins your will be greated with a Installation Wizard. Defaults are fine, do make sure you install the pipeline plugin during the setup though.

Setup your jenkins

It is very important that you activate matrix based security on http://localhost:8787/configureSecurity and give yourself all rights by adding yourself to the matrix and tick all the boxes. (There is a tick-all-boxes icon on the far right)

• Select

  $ docker build -t local_jenkins /opt/docker/jenkins/
  

  7 as the Security Realm
• Select

  $ docker build -t local_jenkins /opt/docker/jenkins/
  

  8 in the Authorization section
• Write your username in the field

  $ docker build -t local_jenkins /opt/docker/jenkins/
  

  9 and click on the

  $ echo "alias localjenkinsrestart='docker stop jenkins;docker rm jenkins;docker run --name jenkins -i -d -p 8787:8080 -p 50000:50000 -v /opt/docker/jenkins/jenkins_home:/var/jenkins_home:rw local_jenkins'" >> ~/.bash_aliases
  $ source .bash_aliases  # To make it work
  

  0 button
• In the table above your username should pop up with a people icon next to it. If it is crossed over you typed your username incorrectly.
• Go to the far right of the table and click on the tick-all-button or manually tick all the boxes in your row.
• Please verify that the checkbox

  $ echo "alias localjenkinsrestart='docker stop jenkins;docker rm jenkins;docker run --name jenkins -i -d -p 8787:8080 -p 50000:50000 -v /opt/docker/jenkins/jenkins_home:/var/jenkins_home:rw local_jenkins'" >> ~/.bash_aliases
  $ source .bash_aliases  # To make it work
  

  1 is unchecked. (Since this Jenkins is only reachable from your computer this isn't such a big deal)
• Click on

  $ echo "alias localjenkinsrestart='docker stop jenkins;docker rm jenkins;docker run --name jenkins -i -d -p 8787:8080 -p 50000:50000 -v /opt/docker/jenkins/jenkins_home:/var/jenkins_home:rw local_jenkins'" >> ~/.bash_aliases
  $ source .bash_aliases  # To make it work
  

  2 and log out of Jenkins and in again just to make sure it works. If it doesn't you have to start over from the beginning and emptying the

  $ docker build -t local_jenkins /opt/docker/jenkins/
  

  4 folder before restarting

Add the git user

We need to allow our git hook to login to our local Jenkins with minimal rights. Just to see and build jobs is sufficient. Therefore we create a user called

$ echo "alias localjenkinsrestart='docker stop jenkins;docker rm jenkins;docker run --name jenkins -i -d -p 8787:8080 -p 50000:50000 -v /opt/docker/jenkins/jenkins_home:/var/jenkins_home:rw local_jenkins'" >> ~/.bash_aliases
$ source .bash_aliases  # To make it work

$ echo "alias localjenkinsrestart='docker stop jenkins;docker rm jenkins;docker run --name jenkins -i -d -p 8787:8080 -p 50000:50000 -v /opt/docker/jenkins/jenkins_home:/var/jenkins_home:rw local_jenkins'" >> ~/.bash_aliases
$ source .bash_aliases  # To make it work

Direct your browser to http://localhost:8787/securityRealm/addUser and add

$ echo "alias localjenkinsrestart='docker stop jenkins;docker rm jenkins;docker run --name jenkins -i -d -p 8787:8080 -p 50000:50000 -v /opt/docker/jenkins/jenkins_home:/var/jenkins_home:rw local_jenkins'" >> ~/.bash_aliases
$ source .bash_aliases  # To make it work

$ echo "alias localjenkinsrestart='docker stop jenkins;docker rm jenkins;docker run --name jenkins -i -d -p 8787:8080 -p 50000:50000 -v /opt/docker/jenkins/jenkins_home:/var/jenkins_home:rw local_jenkins'" >> ~/.bash_aliases
$ source .bash_aliases  # To make it work

$ echo "alias localjenkinsrestart='docker stop jenkins;docker rm jenkins;docker run --name jenkins -i -d -p 8787:8080 -p 50000:50000 -v /opt/docker/jenkins/jenkins_home:/var/jenkins_home:rw local_jenkins'" >> ~/.bash_aliases
$ source .bash_aliases  # To make it work

Add the rights to the git user

Go to the http://localhost:8787/configureSecurity page in your browser. Add the git user to the matrix:

• Write

  $ echo "alias localjenkinsrestart='docker stop jenkins;docker rm jenkins;docker run --name jenkins -i -d -p 8787:8080 -p 50000:50000 -v /opt/docker/jenkins/jenkins_home:/var/jenkins_home:rw local_jenkins'" >> ~/.bash_aliases
  $ source .bash_aliases  # To make it work
  

  4 in the field

  $ docker build -t local_jenkins /opt/docker/jenkins/
  

  9 and click on

  $ echo "alias localjenkinsrestart='docker stop jenkins;docker rm jenkins;docker run --name jenkins -i -d -p 8787:8080 -p 50000:50000 -v /opt/docker/jenkins/jenkins_home:/var/jenkins_home:rw local_jenkins'" >> ~/.bash_aliases
  $ source .bash_aliases  # To make it work
  

  0

Now it is time to check the boxes for minimal rights to the git user. Only these are needed:

• overall:read
• job:build
• job:discover
• job:read

Make sure that the

$ echo "alias localjenkinsrestart='docker stop jenkins;docker rm jenkins;docker run --name jenkins -i -d -p 8787:8080 -p 50000:50000 -v /opt/docker/jenkins/jenkins_home:/var/jenkins_home:rw local_jenkins'" >> ~/.bash_aliases
$ source .bash_aliases  # To make it work

$ echo "alias localjenkinsrestart='docker stop jenkins;docker rm jenkins;docker run --name jenkins -i -d -p 8787:8080 -p 50000:50000 -v /opt/docker/jenkins/jenkins_home:/var/jenkins_home:rw local_jenkins'" >> ~/.bash_aliases
$ source .bash_aliases  # To make it work

Create the pipeline project

We assume we have the username

$ localjenkinsrestart

$ localjenkinsrestart

$ localjenkinsrestart

$ localjenkinsrestart

In your http://localhost:8787 Jenkins add a new pipeline project. I named it hookpipeline for reference.

• Click on

  $ localjenkinsrestart
  

  8 in the Jenkins menu
• Name the project

  $ localjenkinsrestart
  

  9
• Click on Pipeline
• Click

  $ localjenkinsrestart
  $ docker exec -it jenkins /bin/bash
  

  0
• Tick the checkbox

  $ localjenkinsrestart
  $ docker exec -it jenkins /bin/bash
  

  1 in the Build Triggers section. Leave the Schedule empty.
• In the Pipeline section:
  • select

    $ localjenkinsrestart
    $ docker exec -it jenkins /bin/bash
    

    2
  • in the

    $ localjenkinsrestart
    $ docker exec -it jenkins /bin/bash
    

    3 field enter

    $ localjenkinsrestart
    $ docker exec -it jenkins /bin/bash
    

    4
  • in the

    $ localjenkinsrestart
    $ docker exec -it jenkins /bin/bash
    

    5 field enter

    $ localjenkinsrestart
    

    5
• Save the hookpipeline project
• Build the hookpipeline manually once, this is needed for the Poll SCM to start working.

Create the git hook

Go to the

$ localjenkinsrestart
$ docker exec -it jenkins /bin/bash

$ localjenkinsrestart
$ docker exec -it jenkins /bin/bash

#!/bin/sh
BRANCHNAME=$(git rev-parse --abbrev-ref HEAD)
MASTERBRANCH='master'

curl -XPOST -u git:login http://localhost:8787/job/hookpipeline/build
echo "Build triggered successfully on branch: $BRANCHNAME"

Make this file executable:

$ docker build -t local_jenkins /opt/docker/jenkins/

Test the post-commit hook:

$ docker build -t local_jenkins /opt/docker/jenkins/

Check in Jenkins if your hookpipeline project was triggered.

Finally make some arbitrary change to your project, add the changes and do a commit. This will now trigger the pipeline in your local Jenkins.

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