The goal of this project was to streamline deployment and testing of a Nodejs application. Jenkins was used to achieve this as well as deliver status reports via Email and Slack. The app is hosted on Render and the database is MongoDB Atlas.
The app can be accessed here: https://my-ip1-node-app.onrender.com/
NOTE: The app may take about 60 sec to start since free instances on Render spin down due to inactivity.
Setting up the github webhook to trigger the pipeline after any commit:
+ Install ngrok
+ Use ngrok to create a public URL for
the Jenkins container running locally
+ Add the URL as a github webhook
Set up the MongoDB database:
+ Create a cloud-hosted MongoDB cluster
on MongoDB Atlas
+ Add the connection string to the
_config.js and server.js files
Configure the Jenkins pipeline:
+ Build triggers: Ensure "GitHub hook
trigger for GITScm polling" is selected
+ Pipeline: Ensure the "Pipeline script
from SCM" option is selected and set the
SCM as "Git". Include the URL to the
github repository that you configured
the webhook on and specify the branch
that the pipeline will be triggered
from.
+ Set the script path as the name of the
pipeline configuration file. In my case,
it was "Jenkinsfile"
Set up a hosting environment for the application on Render:
+ Create an infrastructure as code
template file that creates a web service
in Render. Refer to the render.yaml
file in this repository.
+ Once the web service is up and running,
copy the deploy hook and save it as an
environment variable in Jenkins. It
will be useful for the "deploy stage"
of the pipeline.
Write the pipeline script (Jenkinsfile):
+ Ensure it uses the nodejs plugin by
referencing it in the "tools" section.
+ Stage1: Clone the git repository
containing the application source code.
+ Stage2: Install the dependencies
required to run the app.
+ Stage3: Test the application
+ Stage4: Deploy the application to
the Render web service.
+ Post stage: In case of any failures,
trigger an email notification message
to send alerts immediately. In case of
a successful build, trigger a
notification message on Slack
+ NOTE: Once this file is commited to the
repository, it will trigger the
pipeline and any subsequent commits
thereafter will also trigger the
pipeline.
Download and configure the necessary plugins for both email and Slack notifications using the following guides:
+ Email: https://naiveskill.com/jenkins-pipeline-email-notification/
+ Slack: https://naiveskill.com/jenkins-pipeline-slack-notification/