Shulou(Shulou.com)06/02 Report--

The topic of this chapter is Jenkins automating docker images and deploying them to the k8s cluster. We will talk about Jenkins publishing to the k8s cluster with one click later.

Installing jenkins requires tomcat to run the application

1. Clean up all default resources and resources under other namespaces

[root@master ~]# kubectl get all --all-namespaces

kubectl delete svc --all;kubectl delete pod --all

2. Download gitlab installation package

On node2, do the following

wget xxx

Install: yum localinstall xxx

Configuration: vim /etc/gitlab/gitlab.rb, modify the following two lines

external_url 'http://192.168.187.102'prometheus_monitoring['enable'] = flase

Restart:

3. Create repository on gitlab and upload code

git add .

git commit -m 'first update'

git push -u origin master

4. install Jenkins

On node1, do the following

Install JDK, install tomcat, install jenkins

[root@node1 ~]# rpm -ivh jdk-12.0.2_linux-x64_bin.rpm

warning: jdk-12.0.2_linux-x64_bin.rpm: Header V3 RSA/SHA256 Signature, key ID ec551f03: NOKEY

Preparing... ################################# [100%]

Updating / installing...

1:jdk-12.0.2-2000:12.0.2-ga ################################# [100%]

[root@node1 ~]# java --version

java 12.0.2 2019-07-16

Java(TM) SE Runtime Environment (build 12.0.2+10)

Java HotSpot(TM) 64-Bit Server VM (build 12.0.2+10, mixed mode, sharing)

Extract tomcat package to specified folder

tar xf apache-tomcat-8.5.45.tar.gz -C /app

Copy the jenkins.war package to tomcat's webapps directory and start tomcat. Since our installation method is based on tomcat, starting tomcat will automatically start jenkins.

[root@node1 ~]# cp jenkins.war /app/apache-tomcat-8.5.45/webapps/

[root@node1 ~]# ls

! anaconda-ks.cfg apache-tomcat-8.5.45.tar.gz jdk-12.0.2_linux-x64_bin.rpm jenkins.war original-ks.cfg

[root@node1 webapps]# /app/apache-tomcat-8.5.45/bin/startup.sh

[root@node1 webapps]# netstat -lntup | grep 8080

tcp6 0 0 :::8080 :::* LISTEN 81725/java

To start, log in to http://192.168.187.101:8080/jenkins on your browser and enter the original password. Copy the password in the following file to here.

[root@node1 secrets]# vim initialAdminPassword

[root@node1 secrets]# pwd

/root/.jenkins/secrets

Next, you will see an interface that allows you to select the startup module and skip to the next step.

Pulling code from gitlab on a machine with jenkins installed, normally pulls successfully

Here is a screenshot of Jenkins pulling code successfully

5. Jenkins automates docker image building

In production, when we click build now on jenkins, a docker image is immediately packaged.

This is our ultimate goal:

A common practice for many of us is to edit a dockerfile while committing code on gitlab. When you click build now on jenkins, jenkins automatically executes docker build to complete the process of building a docker image because of the existence of this dockerfile

a. First create dockerfile file on node2, and edit a file without packaging this file when executing

vi dockerfile

FROM 192.168.187.100:5000/nginx:1.13

ADD . /usr/share/nginx/html #Upload code to this directory

b. Copy docker build, docker push commands from jenkins to the configuration-build-interface, which will be executed when you click build now

docker build

docker push 192.168.187.100:5000/

After execution, you can check docker images to see if the image will be in the mirror pool of the private repository

6. Optimize some configurations in the build

First of all, if you build many times and you want to save the historical version, you don't want the old version to be overwritten, then you need to set the version variable.

In Configure-Build, change the version number to a variable so that it changes with each build

Second, if the code has not changed and we do not want to perform the action of building again, then we need to do a check to check whether the code has been updated and whether there is a new build; here we use the commit id as the basis for judging. If the commit id is the same as last time, we will not build again. If it is inconsistent, we will execute the build command.

7.k8s Cluster Deployment Project

7.1. Create Project Resources

a. Create a deployment with the bird image uploaded to the local private repository as the source.

kubectl run

b. Create an svc that provides external access to the birdie app.

kubectl expose

7.2. Manual implementation of docker upgrade and rollback in k8s

kubectl set image deploy

kubectl rollout undo deploy

7.3. Using jenkins to upgrade and rollback docker in k8s

Integrate the above upgrade and rollback operations into the configuration-build configuration, and let jenkins implement the docker upgrade and rollback;

We can do an experiment by creating an html file in gitlab and building it and uploading the code to a private repository.

Then through jenkins immediate build function to achieve k8s docker resources one-click update, deployment or release.

kubectl -s 192.168.187.100：8080 set image deploy xiaoniao:

Question:

1. After the jenkins installation is completed, the initialization startup has been very slow, showing that the load is in progress, and the modified configuration does not take effect.

2.jenkins one-click build to complete the update and release of docker resources in k8s, very awesome, hope to have the opportunity to understand its application status in the production environment

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