Actual combat: docker-jenkins

In the last article, we talked about the minimum implementation of dockerfile , but it also raised a problem. Even if docker solves the environment and deployment problems, CICD still makes people feel tired. This chapter generates jenkins container through docker and combines jenkins with github , to achieve a certain degree of CI

desired effect

I hope I push the code to jenkins after git push, click publish in jenkins, I can push my code to the server, I browse the page, and I can see the effect immediately

git push to the repository, and click publish on jenkins to publish.

Jenkins binds remote warehouse and server

After git push to the warehouse, jenkins listens and executes the script

Delete the original container and generate a new container to map out the port

Jenkins Quick Start

It is cicd written in java language,

It is a set of cicd system written in java, which can deal with the server through ssh

Realize ideas

jenkins

Implementation steps

Step 1: Pull the jenkins image to generate a container for the image

Step 2: Install and configure jenkins

Step 3: Prepare the node service

Step 4: Jenkins deploys the node service

Step 1: Generate a jenkins container

First pull jenkins from dockerhub

 docker pull jenkins/jenkins:lts

Create a jenkins directory

 mkdir /home/johan/www/jenkins

Elevate permissions on this file

 sudo chmod -R 777 /home/johan/www/jenkins

Generate a container with jenkins/jenkins:lts as the image

 docker run --name jenkins -p 8080:8080 -p 50000:50000 -d -v /home/johan/www/jenkins:/var/jenkins_home jenkins/jenkins:lts

-d : running in the background

-v : Data volume, which maps the contents of the container to the local machine

View container internal logs

 docker logs jenkins

Enter the domain name URL to see if the installation is successful jenkins

See unlocking jenkins, enter the password in the logs to unlock

Step 2: Install and configure jenkins

Install the jenkins plug-in according to the recommended plug-in installation

fit jenkins

It takes a while to download these plugins

If an error is reported, try again, kaka is dry

Create an administrator account

Save successfully, start using jenkins

change source

https://mirrors.tuna.tsinghua.edu.cn/jenkins/updates/update-center.json

Go to System Management -> Plugin Management -> Advanced -> Pull to the bottom

download ssh plugin

Go to System Administration -> Plugin Management -> Optional Plugins

Search for "Publish over SSH" and install

configure ssh

Go to System Management -> System Configuration -> Pull to the bottom (Publish over SSH)

use password

Click Test Configuration, it has been connected to the server

Install the nodejs plugin

The node plugin needs to be used when running the node project. Install it first here.

Go to System Administration -> Plugin Management -> Optional Plugins

Search for node and install it

Configure node globally

Go to System Administration -> Global Tools Configuration -> NodeJS

apply and save it

The construction of jenkins has come to an end

Step 3: Prepare the node service

Let's take the koa mentioned in the previous chapter as an example to explain

Generate .gitignore file and write node_modules

Upload dockerfile_koa_demo to github

 git init
git add .
git commit -m 'first_commit'
git remote add origin https://github.com/johanazhu/dockerfile_koa_server.git
git push -u origin master

Step 4: Jenkins deploys the node service

Create a task

task name

mission details

code show as below:

 docker stop koa_server_container
docker rm koa_server_container
docker rmi johanbo/koa_server:v.1.0.0
cd /home/johan/www/jenkins/workspace/dockerfile_koa_server
docker build . -t johanbo/koa_server:v1.0.0
docker run -d --name koa_server_container -p 3011:3010  johanbo/koa_server:v1.0.0

Interpret the above code:

Line 1: Stop the koa_server_container container

Second line: delete this container

Line 3: Delete the image that generated this container

The fourth line: enter the directory relative to the jenkins data volume in the server

Note: dockerfile_koa_server the name you used to create the project

Line 5: Generate an image named johanbo/koa_server:v1.0.0

The sixth line: generate a container named koa_server_container with johanbo/koa_server:v1.0.0 as the mirror, and map the 3011 port of the local machine with the 3010 of the container

Apply and save

Build a service now

The discovery is successful, and you can see "hello, docker"

Change the original file app.js locally

 app.use(async (ctx) => {
    ctx.body = 'hello, docker, jenkins';
});

Submit code to github

Deploy the node service again through jenkins

The build is complete, refresh the browser, and find that the content has been replaced

PS: This service is now off the shelf

Summarize

In actual development, I actually stepped on a lot of pits. Although there are good tutorials written by others, there are various limitations when doing it yourself, such as different operating systems, secret keys, SSH plug-ins of jenkins, and docker commands are supported in jenkins plugin integration issues, etc.

There are also many tutorials about the two types on the Internet, but most of them are default: jenkins and the application are deployed on the same server, so that the mirror can be built in the corresponding file,

But what if jenkins and the application are deployed on two servers? leave it to the next challenger

Reference article

• How to build serverless applications with Jenkins, Docker and CI/CD?
• [Hands-on series] Jenkins+Docker automated deployment of vue projects
• Failed to add SSH key. Message "invalid privatekey" problem
• Problems encountered when jenkins configures publish over ssh
• Build, Publish, Deploy and Test Docker images and containers with Jenkins Workflow
• Building Docker Images using Jenkins step by step | Devops Integration Live Demo | JavaTechie