{"id":717,"date":"2017-10-20T06:19:36","date_gmt":"2017-10-20T06:19:36","guid":{"rendered":"https:\/\/blog.ngocha.biz\/?p=717"},"modified":"2017-10-20T06:19:36","modified_gmt":"2017-10-20T06:19:36","slug":"jenkins-master-build-slaves-docker-container","status":"publish","type":"post","link":"https:\/\/blog.ngocha.biz\/?p=717","title":{"rendered":"Setup Jenkins master and Build Slaves as Docker Container"},"content":{"rendered":"

Do you want dockerized Jenkins which includes the configuration for build slaves also as Docker containers? So that you can run this image using docker command, then bang, everything is ready to run your Jenkins job on docker slave. Now let’s make this happen.<\/p>\n

Install Jenkins as docker container<\/h3>\n

Go to jenkins website (https:\/\/jenkins.io\/doc\/book\/getting-started\/installing\/<\/a>) and find “Docker” section, before executing the command docker run -d -p 49001:8080 -v $PWD\/jenkins:\/var\/jenkins_home -t jenkins\/jenkins<\/code>, we need to let “jenkins” be the owner of the jenkins directory on host using its UUID: <\/p>\n

sudo chown -R 1000:1000 \/opt\/jenkins_home<\/code><\/pre>\n
Otherwise, you will find the jenkins docker container cannot be started, just exit after the container created, that’s because the jenkins container user by default is “jenkins”,<\/p>\n
Now you can access Jenkins from your browser, for example: http:\/\/[your Jenkins ip]:49001\/, create job and build your project from your Jenkins master container<\/p>\n
Setup Build Slave as docker container<\/h2>\n
Although you can add VM as build slave in Jenkins, it’s more flexible and convenient to make build slave as docker container, because you don’t need to maintain each slave VM, you can just give Jenkins a slave host’s IP and slave’s docker image template, then Jenkins can create slave as docker container on that host. Jenkins make this happen by a plugin called DockerPlugin.<\/p>\n
Let’s see how to install and configure this plugin.<\/p>\n
Install the plugin<\/h4>\n
Navigate to the Manage Jenkins > Manage Plugins page in the web UI. Find DockerPlugin and install it. See https:\/\/jenkins.io\/doc\/book\/managing\/plugins\/<\/a> for reference.<\/p>\n
Plugin Configuration<\/h4>\n
Create your slave image.<\/h3>\n
Step 1:<\/strong> Find steps in official site https:\/\/wiki.jenkins.io\/display\/JENKINS\/Docker+Plugin, see the section “Creating a docker image”, commands include: <\/p>\n
docker pull ubuntu\ndocker run -i -t ubuntu \/bin\/bash\napt-get update\napt-get install openssh-server\nmkdir \/var\/run\/sshd\napt-get install openjdk-6-jdk\nadduser jenkins\n\/usr\/sbin\/sshd\nexit<\/code><\/pre>\n
However, the steps are insufficient if your build slave needs to build your project’s docker image, create docker container and build your project because you can not run docker command in the ubuntu container after these steps. The aim is not docker-in-docker, i.e., docker container running in another docker container, which is another more complicated case. We just need to install the docker binary in docker container and mount the docker socket (by volume “\/var\/run\/docker.sock”) so as docker command can be executed in the container. So add the below steps<\/p>\n