Building Jenkins Pipeline Free style

In this blog I will be discussing on working on simple Free-Style project

Seletct Free style project
Project Name: Generate ASCII Artwork
Select General Configuration.
Description: Generate ASCII Artwork using Cowsay library and AdviceSlip Rest API
Build Environment -- Add timestamps to the Console Output
Build Steps -- Execute Shell

# See the list of available environment variables
# Build a message by invoking ADVICESLIP API

curl -s https://api.adviceslip.com/advice > advice.json
cat advice.json

# Test to make sure the advice message has more than 5 words.
cat advice.json | jq -r .slip.advice > advice.message
[ $(wc -w < advice.message) -gt 5 ] && echo "Advice has more than 5 words" || (echo "Advice $(cat advice.message) has 5 words")

# Deploy
sudo apt-get install cowsay -y
echo $PATH
export PATH="$PATH:/usr/games:/usr/local/games
echo $PATH
cat advice.message | cowsay -f $(ls /usr/share/cowsay/cows | shuf -n 1)

Save and Apply: A work space will be allocated for this pipeline.
Build the pipeline
Check the console output of log info

The pipeline fails because the jenkins is not able to access the system environment variables. Jenkins runs as an isolated environment with jenkins user.

This can be resolved by envs place after the installation of cowsay.

echo $PATH
export PATH="$PATH:/usr/games:/usr/local/games
echo $PATH

If the multiple jenkins jobs need these envs as dependencies pass them in the environment key-value. For this freestyle project.

In the workspace the file downloaded was stored.

Chained Freestyle Project

The previous shell script has three stages if take them as

Build
Test
Deploy So, lets seperate these into each freestyle job. ### Build job

# Build a message by invoking ADVICESLIP API

curl -s https://api.adviceslip.com/advice > advice.json
cat advice.json

Test Job

It will fail if manually triggered.
Because the build job has seperate workspace and test job has different.

# Test to make sure the advice message has more than 5 words.
cat advice.json | jq -r .slip.advice > advice.message
[ $(wc -w < advice.message) -gt 5 ] && echo "Advice has more than 5 words" || (echo "Advice $(cat advice.message) has 5 words")

Now we chain the build job and test jobs.
Trigger only the build jobs success then test job. Under the build job configuration. Add the test job name in build job post actions save and apply.

lets trigger the build job then look at the test job. Yes now they are linked even though the test job failed. Now Look at Plugins. Some plugins info are below.

Where plugin store and their format, priority.

Installing plugins

To install plugins go to ManageJenkins > Plugin

Updates
Available plugins
installed plugins

Lets install Copy Artifact for this project.For documentation Copy Artifact

in the build job enable the artifacts copyt to test-job and enable the archive advice.json file. Save and apply.

In the test job add the build step as first build step for getting the artifacts. To move the build steps use drag-and-drop.

Not the build and test jobs are working fine.

Deploy job

Create deploy job and configure the build step with below and add the prior step as copy artifacts from test-job only if the testjob is stable. Also give permissions to copy artifacts from the test job.

# Deploy
sudo apt-get install cowsay -y
cat advice.message | cowsay -f $(ls /usr/share/cowsay/cows | shuf -n 1)

If you faced any issues with the deploy-job then try to replicate same as test job configuration.

Finally the three jobs are chained. Now to visualize the chanied jobs
install the Yet another build visualizer then goto any of the chained project.

Disadvantages of Freestyle pipeline:

start the jobs and run systemctl stop jenkins. It will stop the jobs running. Try 'systemctl start jenkins` check the jobs restarted where they failed. Freestyle project pipelines would not auto-restart.

Lets try to add figerprint to the advice.json and advice.message file. Jenkins will create a MD5 checksum to track the jobs used the file, it only store the checksum not the file itself. Configure it as a post action save and apply.