Continuous Deployment on Jenkins and Docker

Miguel Ángel García Martínez

What are we going to see?

~~Jenkins~~
~~Docker~~
~~Docker-Compose~~
Continuous Integration
Continuous Deployment

Why?

Individuals and interactions over processes and tools

How are we going to do that?

Running a Jenkins server
Configuring a little project
Testing and deploying when it changes

How are we going to do that, exactly?

Run Jenkins server
Run Jenkins server on Docker
Configure the job te be launched
Run jenkins-swarm slave
Run jenkins-swarm slave on Docker
Create a docker-compose with both
Add master branch continuous integration

All of this in 5 minutes

Installing Jenkins:


 wget http://mirrors.jenkins-ci.org/war/latest/jenkins.war
 java -jar jenkins.war

Requirements:

Yes, it requires java

Jenkins landing page

Installing Jenkins, Docker mode:


 docker run -p 8080:8080 -p 50000:50000 jenkins

Docker glossary:

Image: like a class
Container: like an object
Volume: a mount point

Docker in a nutshell:

docker images Shows all downloaded images
docker ps Shows all running containers
docker ps -a Shows all created containers
docker run <image>
download the image if necessary, create a container and run it.
docker exec -ti <container> <command>
Executes the command on container

Configuring a job in jenkins:

Drawbacks:

How to prevent installing python, ruby, java, etc. in the same host?
How to prevent installing two different versions of python, ruby, java, etc. in the same host?
How to prevent installing two different versions of a library?
How to migrate the current infrastructure to production?
Get rid of packaging systems, like deb, rpm, ...

Our own image (reduced)


FROM java:8-jdk
RUN apt-get update \
    && apt-get install -y \
               git \
               wget \
               python3 \
               python3-pip
RUN apt-get clean
RUN wget http://[...]/swarm-client-2.0-jar-with-dependencies.jar

COPY jenkins-slave.sh /usr/local/bin/jenkins-slave.sh

VOLUME /home/jenkins-slave

ENTRYPOINT ["/usr/local/bin/jenkins-slave.sh"]

Docker-compose

Allows us to create a default docker configuration
Allows us to create a network of dockers
And all of this in a simple YAML file

Docker-compose


version: '2'
services:
  master:
    image: jenkins:2.7.1
    ports:
      - 8080:8080
    volumes:
      - ./data/master:/var/jenkins_home

  slave:
    build: slave
    command: -master http://master:8080 -executors 1
      -labels python -name builder
      -username swarm -password swarm
    links:
      - master

What does we have?

What does we want?

Drawbacks

Database preloaded data
Third party services (RabbitMQ, ...)
New development requirements
Security issues