How to Setup Jenkins in a few minutes!

Have you ever gone through the situation when your Jenkins goes down without any backup of your jobs and then you have to waste a lot of time and effort to re-create all your resources from scratch? We had also faced the same problem, but now We are free from it We have found a solution.

You might really want to know, how. What if, I say you can create a Jenkins server with the same configuration without any efforts and most importantly without wasting months, days, or even hours. Yes, you can set up your Jenkins in just 30 mins as we did.

Continue reading “How to Setup Jenkins in a few minutes!”

Automatically Backup Alibaba MySQL using Grandfather-Father-Son Strategy

 

So, basically what is Grandfather-father-son or GFS?

GFS backup is a common rotation scheme for backup, in which there are three or more backup cycles, such as daily, weekly, and monthly. Typically, It consists of daily backups (son, at fixed intervals of hours in a day), a weekly full backup (father, once a week), and monthly full backup (Grandfather, once a month).

Continue reading “Automatically Backup Alibaba MySQL using Grandfather-Father-Son Strategy”

GitOps with Jenkins and Kubernetes

While tools like Kubernetes is becoming an essential need for modern cloud-based infrastructure, there is a high potential for cloud-native CI/CD. To achieve that there is a philosophical approach has emerged i.e. GitOps. As we have discussed the important principles of GitOps in our previous blog, So in this blog, we will see how to implement GitOps in our current DevOps processes, and finally GitOps implementation in a light manner. If you haven’t gone through our previous blog, here you can take a look at it.

Continue reading “GitOps with Jenkins and Kubernetes”

Achieve SSO in Privately Hosted Jenkins

Introduction

Providing OAuth 2.0 user authentication directly or using Google+ Sign-in reduces your CI overhead. It also provides a trusted and secure login system that’s familiar to users, consistent across devices, and removes the burden of users having to remember another username and password. One of the hurdles in implementing a Gmail authentication is that Google developer console and your  Jenkins server should be in the same network or in simple terms they can talk to each other.

Resources Used

  • Privately Hosted Jenkins
  • Google developer console
  • Ngrok
In this blog, I’m trying to explain how to integrate Gmail authentication feature in your privately hosted Jenkins server so that you get free of filling the form by the time of creating a new user.

Setup 1: Setup Ngrok

NGROK
 
Ngrok is multiplatform tunneling, reverse proxy software that establishes secure tunnels from a public endpoint such as the internet to a locally running network service while capturing all traffic for detailed inspection and replay.
We are using Ngrok to host our Jenkins service (running on port 8080) to public IP.

 
Go to google and search for Download Ngrok.
 
 
 
Either Login with google account or do Ngrok own signup.
 
 
After Logged in Ngrok Download it.
 
 
After Download Ngrok, Go to the console and unzip the downloaded zip file and then move it to /usr/local/bin.
Note: Moving part is optional, we do so for accessing ngrok from anywhere.
 
 
 
Go to ngrok UI page , copy the authentication key and paste it.
Note: Remove ” . / ” sign because we moved ngrok file to /usr/local/bin
 
 
 Major configuration for Ngrok is done. Now type the command:
ngrok http 8080
 Assuming that Jenkins is running on port 8080.
 
 
Now Ngrok Host our Jenkins Service to public IP.
 
Copy this IP, we will use it in the google developer console.
 
Note: Make this terminal up and running.(don’t do ctrl+c)

Step 2: Setup Google Developer Console

Go to google and search for google developer console.
 
 
After sign in into google developer console, we will redirect to Google developer console UI screen.
Go to Select a project  → New Project
 
 
Give Project Name, here I will use “JenkinsGmailAuthentication” and create a project. Creating a project takes 1 or 2 minutes.
 
 
After Project created, we will be redirected to the UI page as shown below. Now click on on the “Credentials” Tab on the left slide bar.
 
 
 
After Go to the OAuth consent screen tab and give the below entries. Here I will give Application name to “JenkinsGmailAuthentication”.
 
 
The important part of the Google developer console is Public IP we created using Ngrok. Copy Public IP in Authorized domains and note to remove ” http:// ” in Authorized domains.
 
 
After Setting OAuth consent screen, Go to   “Credentials Tab”→ Create Credentials→OAuthClientID
 
 
Select Application type as Web Application, give the name “JenkinsGmailAuthentication”.
Major Part of Create Credential has Authorized JavaScript origins and Authorized redirect URIs.
 
 
Copy Client ID and Client Secret because we are going to use these in Jenkins.
 

Step 3: Setup Jenkins

I am assuming that Jenkins is already installed in your system.
Go to Manage Jenkins → Manage Plugins→ Available
 
 
Search for “Google Login Plugin” and add it.
 
 
Go to Manage Jenkins → Configure Global Security
 
 
The major part of Jenkins Setup is to Configure Global Security.
Check the Enable security → Login with Google and Paste the Client ID and Client secret generated in Create Credential Step and Save.
 
 
Up to here, we are done with the Setup part.
Now Click on login button on Jenkins UI, you will redirect to Gmail for login.
 
 
Select the account from which you want to log in.
 
 
After selecting Account you will redirect to Jenkins and you are logged in as selected user.
 
 
You may be facing a problem when you log in again.
Logout from the current user and login again.
 
 
After redirected to Gmail select another user.
 
 
After selecting user you will be redirected to Error Page showing: HTTP ERROR 404.
 
 
Don’t worry, you have to just remove “securityRealm/” or enter again “localhost:8080”.
 
 
You are logged in with the selected user.
 
 
So now you know how to do Gmail Authentication between Google developer console and Jenkins when they are not directly reachable to each other.
Here the main bridge between both is Ngrok which host our Privately hosted Jenkins to outer internet.
 
 
 

Jenkins Pipeline Global Shared Libraries

When we say CI/CD as code, it should have modularity and reusability which results in Reducing integration problems and allowing you to deliver software more rapidly.

Jenkins Shared library is the concept of having a common pipeline code in the version control system that can be used by any number of pipelines just by referencing it. In fact, multiple teams can use the same library for their pipelines.

Our thought is putting all pipeline functions in vars is much more practical approach, while there is no other good way to do inheritance, we wanted to use Jenkins Pipelines the right way but it has turned out to be far more practical to use vars for global functions.

Practical Strategy
As we know Jenkins Pipeline’s shared library support allows us to define and develop a set of shared pipeline helpers in this repository and provides a straightforward way of using those functions in a Jenkinsfile.This simple example will just illustrate how you can provide input to a pipeline with a simple YAML file so you can centralize all of your pipelines into one library. The Jenkins shared library example:And the example app that uses it:

Directory Structure

You would have the following folder structure in a git repo:

└── vars
    ├── opstreePipeline.groovy
    ├── opstreeStatefulPipeline.groovy
    ├── opstreeStubsPipeline.groovy
    └── pipelineConfig.groovy

Setting up Library in Jenkins Console.

This repo would be configured in under Manage Jenkins > Configure System in the Global Pipeline Libraries section. In that section Jenkins requires you give this library a Name. Example opstree-library

Pipeline.yaml

Let’s assume that project repository would have a pipeline.yaml file in the project root that would provide input to the pipeline:Pipeline.yaml

ENVIRONMENT_NAME: test
SERVICE_NAME: opstree-service
DB_PORT: 3079
REDIS_PORT: 6079

Jenkinsfile

Then, to utilize the shared pipeline library, the Jenkinsfile in the root of the project repo would look like:

@Library ('opstree-library@master') _
opstreePipeline()

PipelineConfig.groovy

So how does it all work? First, the following function is called to get all of the configuration data from the pipeline.yaml file:

def call() {
  Map pipelineConfig = readYaml(file: "${WORKSPACE}/pipeline.yaml")
  return pipelineConfig
}

opstreePipeline.groovy

You can see the call to this function in opstreePipeline(), which is called by the Jenkinsfile.

def call() {
    node('Slave1') {

        stage('Checkout') {
            checkout scm
        }

         def p = pipelineConfig()

        stage('Prerequistes'){
            serviceName = sh (
                    script: "echo ${p.SERVICE_NAME}|cut -d '-' -f 1",
                    returnStdout: true
                ).trim()
        }

        stage('Build & Test') {
                sh "mvn --version"
                sh "mvn -Ddb_port=${p.DB_PORT} -Dredis_port=${p.REDIS_PORT} clean install"
        }

        stage ('Push Docker Image') {
            docker.withRegistry('https://registry-opstree.com', 'dockerhub') {
                sh "docker build -t opstree/${p.SERVICE_NAME}:${BUILD_NUMBER} ."
                sh "docker push opstree/${p.SERVICE_NAME}:${BUILD_NUMBER}"
            }
        }

        stage ('Deploy') {
            echo "We are going to deploy ${p.SERVICE_NAME}"
            sh "kubectl set image deployment/${p.SERVICE_NAME} ${p.SERVICE_NAME}=opstree/${p.SERVICE_NAME}:${BUILD_NUMBER} "
            sh "kubectl rollout status deployment/${p.SERVICE_NAME} -n ${p.ENVIRONMENT_NAME} "

    }
}

You can see the logic easily here. The pipeline is checking if the developer wants to deploy on which environment what db_port needs to be there.

Benefits

The benefits of this approach are many, some of them are as mentioned below:

  • How to write groovy code is now none of the developer’s perspective.
  • Structure of the Pipeline.yaml is really flexible, where entire data structures can be passed as input to the pipeline.
  • Code redundancy saved to a large extent.

 Jenkinsfiles could actually just look more commonly, like this:

@Library ('opstree-library@master') _
opstreePipeline()

and opstreePipeline() would just read the the project type from pipeline.yaml and dynamically run the exact function, like opstreeStatefulPipeline(), opstreeStubsPipeline.groovy() . since pipeline are not exactly groovy, this isn’t possible. So one of the drawback is that each project would have to have a different-looking Jenkinsfile. The solution is in progress!So, what do you think?

Reference links: 
Image: Google image search (jenkins.io)