Jenkins master + OSX slaves fleet dockerized - docker

I see no problem with dockerizing Jenkins master (there is even an image ready to use) however I would like to dockerize also slaves. However I'd like these slaves to run iOS builds, so it neeeds slaves to run OS X. Is it doable? Maybe Vagrant, Puppet, Chef anything else could help to automate slaves provisioning?

So you can't use Docker on iOS so you'll need something else there but otherwise this kind of thing is usually handled via Jenkins plugins instead of an external configuration management tool. Jenkins likes to controls its own universe.

There is a Docker Plugin which allows you to deploy dockerized slaves. Follow the documentation, it is pretty simple (no chef/puppet needed)
The problem is that I am not sure that it is possible to have XCode inside the docker container.
Try docker search OSX and docker search Xcode for the image in the Docker Hub.

Related

What's the benefits of docker with Jenkins Pipelines?

I'm new to Jenkins/Docker. So far I've found lots of Jenkins official Documents recommended to be used with Docker. But the necessity and advantages of running Jenkins as a docker container remain vague to me. In my case, it's a node/react app and environment required is not complicated.
Disadvantages I've found running Jenkins as a Docker container:
High usage of hard drive
Directory path in docker container is more complicated to deal with, esp when working with ssh in pipeline scripts
Without docker, I can easily achieve the same and there's also blueocean plugin available.
So, what's the main benefits of Docker with Jenkins/Jenkins Pipeline? Are there pitfalls for my node application using Jenkins without Docker? Articles to help me dive into are also appreciated.
Jenkins as Code
The main advantages of Jenkins in Docker is that it helps you to get: Jenkins as Code
Advantages of Jenkins as code are:
SCM: Code can be in put under version control
History is transparant, backup and roll-back becomes easy.
The code is the documentation of your Jenkins setup.
Jenkins becomes portable, so you can run Jenkins locally to try new plugins etc.
Jenkins pipelines work really well with Docker. As #Ivthillo mentioned: there is no need to install additional tools, you just use images of these tool. Jenkins will download them from internet for you (Docker Hub).
For each stage in the pipeline you can use a different image (i.e. tool). Essentially you get "micro Jenkins agents" which only exists temporary. This makes your Jenkins setup much more clean.
Disadvantage is:
Jenkins initial (Groovy) configuration is poorly documented on the web.
Simple Node setup
Most arguments also holds for a simple Node setup.
Change the node version or run multiple job each with a different Node version becomes easy.
Add your Jenkinsfile inside the Node repo. So everyone with a Jenkins+Docker setup can run your CI/CD.
And finaly: gather knowledge on running your app inside a container will enable your to run your production app in Docker in the future.
Getting started
A while ago I have written an small blog on how to get started with Jenkins and Docker, i.e. create a Jenkins image for development which you can launch and destroy in seconds.

How to deploy/run a Docker image from a build server

Having built,run and executed tests against a docker image on a CI build server(TeamCity2017), how should we deploy it to further machines?
How, for example, if we push it to a Docker registry, would our CI server instruct the target machine to pull and run the image? I.e. where it an application we would use Octopus for this deployment step, but our Octopus server doesn't support Docker deployments as yet.
Any guidance appreciated.
Michael McD.
I would use Octo to deploy your images onto target machines. You'd need to use powershell scripts to have your machines run the images. Or you can use something like Rancher, which is a docker swarm manager. There is no feasible way to have TeamCity deploy your images. The software simply isn't built to be able to do deploys.
The Rancher solution would not be automated, at least not to my knowledge. You would have to trigger upgrades when a new image is pushed to the docker registry.

CI/CD with Docker - what is the final deployment step?

I am developing a small website (Ruby/Sinatra) to be used internally where I work. (Simply, it crunches some source data and generates reports.)
I'm want to deploy it using Docker and have a set up that works on my dev environment, but I'm trying to understand the workflow for "production" deployment (we're using Jenkins).
I've read lots of articles about deployment workflows using Docker, but they all seem to stop at "and then push your image to the Docker registry". What seems to be missing is how to then take that image and actually update the application.
I appreciate that every application is likely to be different, but what is the next step? I'm aware of lots of different frameworks like Chef, Puppet, Ansible that could be used, but my question really is - how do I integrate that into my CI/CD pipeline? E.g. does a job "push" the changes to the production server, or should a Jenkins slave be running on the production server to execute a job directly on the server?
There are several orchestration tools like docker-swarm, kubernetes and rancher. In docker swarm for example you create services and can update the versions in blue-green deployment manner also for just one instance (then there is no blue-green :) ) and if you just use docker run you should check your running container, stop and remove it if its running an start your docker container with the newer image version.
It depends on how your application is configured to run. In my case, I have a call to "docker run" in a systemd script. It's configured to just restart if it ever stops.
So, in my Jenkinsfile, after I push the image to the registry, I do a "docker pull" (my Jenkins agent is running on the same box that the application is running on), and then a "docker stop". That causes the application to exit, then restarts, which causes it to get the new version that was just pulled, and now it's running the new version.

Run Jenkins master and slave with Docker

I want to setup Jenkins master on server A and slave on server B with use of Docker.
Both servers are virtual machines dedicated for Jenkins.
Currently I have started Docker container on server A for master, based on the official Jenkins docker image. But what docker image should I use for Jenkins slave?
That actually depends on the environment and tools you need in your build environment. For example, if you build a C project, you would need an image containing a C compiler and possibly make if you use Makefiles. If you build a Java project, you would need a JDK with a Java compiler and possibly Ant / Maven / Gradle if you use them as part of your build.
You can use the evarga/jenkins-slave as a good starting point for your build slave.
This image already contains JDK. If you simply need JDK and Maven on your build slave, you can build your Docker image with the following Dockerfile:
FROM evarga/jenkins-slave
run apt-get install maven
Using Docker images for build slaves is actually a good idea. Some of the reasons appear at Templating Jenkins Build Environments with Docker Containers:
Docker has established itself as a popular and convenient way to
bootstrap isolated and reproducible environments, which enables Docker
containers to be the most maintainable slave environments. Docker
containers’ tooling and other configurations can be version controlled
in an environment definition called a Dockerfile, and Dockerfiles
allows multiple identical containers can be created quickly using this
definition or for more customized off-shoots to be created by using
that Dockerfile’s image as a base.
I suggest you take trying to use dynamic|ephemeral docker nodes, instead of manually creating nodes and connecting to them via ssh. Take a look at https://engineering.riotgames.com/news/putting-jenkins-docker-container, it's very powerful and I think it's one of killer usecases for Docker.

Is there a stable plugin for Jenkins for running builds on VMs?

Travis CI has a really nice feature, builds are run within VirtualBox VMs. Each time a build is started, the box is refreshed from a snapshot and the code copied on to it. Any problems with the build cannot affect the host, and you can use any OS to run your builds on.
This would be really good, for example, compiling and testing code on a guest OS that matches your production env. Also, you can keep your host free of any installation dependencies you might need (e.g. a database server) and run ITs without worrying about things like port conflicts.
Does such a thing exist for Jenkins?
Check out the Vagrant Plugin https://wiki.jenkins-ci.org/display/JENKINS/Vagrant-plugin
This plugin allows booting of Vagrant virtual machines, provisioning them and also executing scripts inside of them
You can run Jenkins in a Master Slave Setup. Your Master instance manages all the jobs but lets all the slaves do the actual work. These Slaves can be VMs or physical machines. Go To Manage Jenkins -> Manage Nodes -> New Node to add Nodes to your Jenkins Setup.
There is the vSphere Cloud Plugin and the Scripted Cloud Plugin that can be used for this purpose.

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