# Continuous Integration using Jenkins for Backend(NodeJs, Python, Angular)

Before beginning to this article make sure [Jenkins Server](https://jenkins-ci.org/) is already setup and running. This article covers how to use Jenkins for build automation and deployment over server for script based programming languages.

**Step 1: Configure Machine:**

> **1.1 Python Prerequisites:** Run the following commands to install essential packages.

sudo apt-get update

sudo apt-get install -y build-essential git-core python-dev python-virtualenv nginx supervisor

> **1.2 Node Prerequisites:**Run the following commands to install essential packages.

sudo apt-get update  
sudo apt-get install nodejs  
sudo apt-get install npm

> **1.3 Angular** **Prerequisites:** Run the following commands to install essential packages.

sudo apt-get update  
sudo apt-get install nodejs  
sudo apt-get install npm  
`sudo npm install -g @angular/cli`

**Step 2: Project Setup and Configurations:**

> 2.1 Jenkins → New Item → Freestyle project

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1669457294976/1oCNecp7I.png)

> *2.2 General*

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1669457296413/4uxiy1Mtq.png)

For saving the project repository in different workspace select “use custom workspace” as follows:

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1669457297730/lz5xlxJMY.png)

> 2.3 Source Code Management

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1669457299034/ZZnNX_PiE.png)

**Add repository URL, select credentials and specify the source branch to pull.**

> 2.4 Build Triggers

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1669457300970/y6nHyCROC.png)

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1669457302290/CxmxbwcQ2.png)

> 2.5 Build: Execute using shell script

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1669457303521/JlCQtqPqR.png)

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1669457304823/vEht4md6C.png)

**Deploying application on server using script**

**Step 3: Deployment Scripts:** This script will cover the following.

**Step 3: Deployment Scripts:** This script will cover the following.

> Pull the latest code to the server

> Run database migrations

> Collect static files

> Restart application

ssh <user>@<machine-ip> /home/ubuntu/BackendTest/Scripts/./deploy.bash <Branch>

> *3.1 Python Script*

#!/bin/bash

echo "Starting script ..."

user = 'myuser'

projectDir = 'MyApp'

supervisorapp = 'app'

echo "Switching to user..."

sudo -u $user bash << EOF

echo "In"

echo "Switching to project directory..."

cd "/home/$user/$projectDir/"

echo "Activating Virtual Environment..."

source venv/bin/activate

echo "Pull latest code from branch passed as argument..."

git pull origin $1  
git checkout $1

echo "Installing Requirements..."

pip install -r requirements.txt

echo "Running migrate for any database migrations..."

python manage.py migrate

echo "Running collectstatic..."

python manage.py collectstatic  <<<yes

EOF

echo "Out"

whoami

echo "Restarting app using supervisor ... "

sudo supervisorctl restart $supervisorapp

> 3.2 Node Script

#!/bin/bash

echo "Starting script ..."

user = 'myuser'

projectDir = 'MyApp'

echo "Switching to project directory..."

cd "/home/$user/$projectDir/"

echo "Pull latest code from branch passed as argument..."

git pull origin $1  
git checkout $1

echo "Updating dependencies..."

npm i

echo "Restarting Process Manager..."

pm2 restart all

> 3.3 Angular Script

#!/bin/bash

echo "Starting script ..."

user = 'myuser'

projectDir = 'MyApp'

echo "Switching to project directory..."

cd "/home/$user/$projectDir/"

echo "Pull latest code from branch passed as argument..."

git pull origin $1  
git checkout $1

echo "Updating dependencies..."

npm i

echo "Creating Build..."

ng build --prod --build-optimizer --env=prod

echo "Switching to build directory..."

cd "dist"

echo "Restarting Process Manager..."

**Script 4: Generate an SSH key on Jenkins machine and add your public key to the server for authentication:**

> 4.1 Generate ssh keys for jenkins user.

sudo su jenkins

ssh-keygen -t rsa

> 4.2 Copy public key

cat ~/.ssh/id\_rsa.pub

> 4.3 Add public key to server authorized\_keys

ssh <user>@<machine-ip>

vi ~/.ssh/authorized\_keys

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1669457306040/SBImXAkrn.png)

**Jenkins Command line displaying successful completion of deployment.**

This tutorial has been designed keeping things in mind that Development, Jenkins and Server machines are separate.

In current scenario Jenkins is installed over Mac environment and source is being pushed either from Linux or Windows machine.