Task 2 DevOps using Jenkins, Docker and git

TASK 2 DevOps Integration of Jenkins, Docker and Git 

This Task was a little bit tough but I tried my best to implement it.

Steps to follow to complete this task

1.Create container image that’s has Jenkins installed  using dockerfile

2.When we launch this image, it should automatically starts Jenkins service in the container.

3.Create a job chain of job1, job2, job3 and  job4 using build pipeline plugin in Jenkins

4.Job1 : Pull  the Github repo automatically when some developers push repo to Github.

5.Job2 : By looking at the code or program file, Jenkins should automatically start the respective language interpreter install image container to deploy code ( eg. If code is of  PHP, then Jenkins should start the container that has PHP already installed ).

6.Job3 : Test your app if it  is working or not.

7.Job4 : if app is not working , then send email to developer with error messages.

8.Create One extra job job5 for monitor : If container where app is running. fails due to any reson then this job should automatically start the container again.

Setps 1 and Step 2:

* I have create a DockerFile to setup jenkins inside Docker use the following code for the same:

FROM centos
RUN yum install httpd -y
RUN yum install wget -y
RUN wget -O /etc/yum.repos.d/jenkins.repo https://pkg.jenkins.io/redhat-stable/jenkins.repo
RUN rpm --import https://pkg.jenkins.io/redhat-stable/jenkins.io.key
RUN yum install java-11-openjdk -y
RUN yum install jenkins -y
RUN yum install git -y
RUN echo -e "jenkins ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers
USER jenkins
ENV USER jenkins
CMD ["java", "-jar", "/usr/lib/jenkins/jenkins.war"]

EXPOSE 8080

This Will setup the jenkins for you on the URL https://localhost:9001

* To Build this image use the command:

docker image build -t jenkins:v1 /your/dockerfile/path

* To run this Image use

docker run -it -p 9001:8080 jenkins:v1

****Setp 1 and Step2 Compeleted**************************************

Step 3:

* Now we have to create total 5 jobs

Job 1:

1) Create a Github repo in which you want your code to be stored

2) Now clone your repo from github

3) Now create a post-commit hook by going inside  cd .git/hooks

4) use any text editor and paste the following code

#! /bin/bash

git push

5) Whenever you commit some changes in your code this will automatically push the code to github

Webhook for jenkins job trigger

6) Now create a job1 in jenkins and install git plugin

7) Then enter you github repo url after selecting the git option in SCM category

8) After that use scm poll to monitor the code changes. If the changes are detected than jenkins will automatically pull the repo

Testing if my server is running

**************Job 1 Completed*******************************************

Step 4:

Job 2:

1) Create job2 in jenkins as you created job1 and then to chain it with job2 use build triggers select build after project and write job1

2)    Select trigger only if build is stable and then in execute shell paste the follwing bash script 

3)  For Detecting the programming language or the file extension i used the following code

 

#!/bin/bash -xe

export perl=$(ls | grep .perl | cut -d'.' -f2)
export js=$(ls |grep .js| cut -d'.' -f2)
export php=$(ls |grep .php| cut -d'.' -f2)
export py=$(ls |grep .py| cut -d'.' -f2)

if [ [  "$py" == "py"  ]]
then

   docker pull python

   docker run -d -it --name python -p 8001:80 python:latest

   
elif [ [ "$php" == "php"  ]]
then
   docker pull php

  docker run -d -it --name php -p 8002:80 php:latest

   
elif [[ "$perl" == "perl" ]]
then
   docker pull perl

  docker run -d -it --name perl -p 8003:80 perl:latest

elif [[ "$js" == "js" ]]
then
   docker pull node

 

  docker run -d -it --name node -p 8004:80 python:latest

else
   echo "Unknown format"

You can add more language if you want

If your project only contains a web application with php and html you can use this script

#!/bin/bash -xe

export html=$(sudo ls mytest/ | grep .html | wc –l)
export php=$(sudo ls mytest/ | grep .php | wc –l)  

if echo $php > 0                                                       
then
if sudo docker ps -a | grep phpsetup                 
then
echo "php setup already running"
else
sudo docker run -d -i -t --name phpsetup -p 9001:80 php
sleep 5
sudo docker cp *.php phpsetup:/var/www/html/
fi

elif echo $html > 0                                                       
then
if sudo docker ps -a | grep htmlsetup                 
then
echo "html setup already running"
else
sudo docker run -d -i -t --name htmlsetup -p 9002:80 httpd
sleep 5
sudo docker cp *.php htmlsetup:/usr/local/apache2/htdocs/
fi
fi

***********Job 2 Completed*******************************************

Step 5:

Job3:

 1)  Create job 3 same as we created job 1 and 2

 2)  Copy and paste github url same as job 1

 3)  In build triggers select build after project is  build give name of job 2

 4)  To test it the job and above all code has successfully executed we need to check the exit code of the last run commands or program. we can use the command

* if you want to check the web app status use the following commands

#!/bin/bash -xe

htmlfiles=$(sudo ls *.html)     

phpfiles=$(sudo ls *.php)         

for file in $htmlfiles; do                 

status=$(curl -o /dev/null -s -w "%{http_code}" your ip:port/$file) 

if [ $status == 200 ] ; then       

echo "OK"

else                                       

echo "Error"          

fi

done 

for file in $allphpfiles; do                

status=$(curl -o /dev/null -s -w "%{http_code}" your ip:port/$file)  

if [ $status == 200 ] ; then       

echo "OK"

else                                  

echo "Website not working"          

fi

echo "done"

***********Job 3 Completed*******************************************

Step 6:

job4:  This job will send an email to the Dev team if some error occurs

1)  Create job 4 as we create job 1, 2, 3

2)  Copy and paste github url same as you did in job 1

3)  In build triggers select build after project is build give name as job3

if docker ps | awk '{print$11}' | grep phpsetup
then
echo "php website running"
elif docker ps | awk '{print$11}' | grep htmlsetup
echo "htmlwebsite running"
else
python3 mail.py
fi

4)  For sending an email we have to use python script (mail.py)

1.     import  smtplib

2.     sender ="email address of sender" 

3.     receiver= "email of receiver"         

4.     password= "any password"  

5.     message= "Web application not working"

6.     server=smtplib.SMTP("smtp.gmail.com",587)

7.     server.starttls()

8.     server.login(sender,password)

9.     server.sendmail(sender,receiver,message)

10.   print(“message sended”)

***********Job 4 Completed*******************************************

Step 7:

job5:

    1)    Create job 5 as we create job and and goto configure then

    2)    Copy and paste github url same as you did in job 1

    3)    In build trigger select poll scm and give * * * * * to check changes every one minute

    4)    To check is all the programs are running correctly use

     

     In build select execute shell:

if sudo docker ps -a | grep phpsetup

then

echo "Program running"

else 

sudo docker run -d -i -t --name phpsetup -p 9001:80 phpsetup

fi

if sudo docker ps -a | grep prodserver

then

echo "no need"

else  #else run httpd server

sudo docker run -d -i -t -p 8084:80 -v devops-t2:/usr/local/apache2/htdocs --name prodserver httpd

fi

*******Job 5 Completed*******************************************

After Completing all the above steps your setup for Jenkins, Git and docker is ready

moiz.7152@gmail.com

RISE_2020.68.23.5