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kubernetes-bundle
The kubernetes-bundle allows you to deploy the many services of Kubernetes to a cloud environment and get started using the Kubernetes technology quickly.
Kubernetes
Kubernetes is an open source system for managing containerized applications. Kubernetes uses Docker to run containerized applications.
Juju TL;DR
The Juju system provides provisioning and
orchestration across a variety of clouds and bare metal. A juju bundle
describes collection of services and how they interrelate. juju quickstart allows you to bootstrap a deployment environment and
deploy a bundle.
Dive in!
Install Juju Quickstart
You will need to
install the Juju client and
juju-quickstart as prerequisites. To deploy the bundle use
juju-quickstart which runs on Mac OS (brew install juju-quickstart) or Ubuntu (apt-get install juju-quickstart).
Deploy a Kubernetes Bundle
Use the 'juju quickstart' command to deploy a Kubernetes cluster to any cloud supported by Juju.
The charm store version of the Kubernetes bundle can be deployed as follows:
juju quickstart u/kubernetes/kubernetes-cluster
Note: The charm store bundle may be locked to a specific Kubernetes release.
Alternately you could deploy a Kubernetes bundle straight from github or a file:
juju quickstart -i https://raw.githubusercontent.com/whitmo/bundle-kubernetes/master/bundles.yaml
The command above does few things for you:
- Starts a curses based gui for managing your cloud or MAAS credentials
- Looks for a bootstrapped deployment environment, and bootstraps if required. This will launch a bootstrap node in your chosen deployment environment (machine 0).
- Deploys the Juju GUI to your environment onto the bootstrap node.
- Provisions 4 machines, and deploys the Kubernetes services on top of them (Kubernetes-master, two Kubernetes minions using flannel, and etcd).
- Orchestrates the relations among the services, and exits.
Now you should have a running Kubernetes. Run juju status --format=oneline to see the address of your kubernetes-master unit.
For further reading on Juju Quickstart
Go to the Getting started with Juju guide for more information about deploying a development Kubernetes cluster.
Using the Kubernetes Client
You'll need the Kubernetes command line client, kubectl to interact with the created cluster. The kubectl command is installed on the kubernetes-master charm. If you want to work with the cluster from your computer you will need to install the binary locally.
You can access kubectl by a number ways using juju.
via juju run:
juju run --service kubernetes-master/0 "sudo kubectl get nodes"
via juju ssh:
juju ssh kubernetes-master/0 -t "sudo kubectl get nodes"
You may also SSH to the kubernetes-master unit (juju ssh kubernetes-master/0)
and call kubectl from the command prompt.
See the kubectl documentation for more details of what can be done with the command line tool.
Scaling up the cluster
You can add capacity by adding more Docker units:
juju add-unit docker
Known Limitations
Kubernetes currently has several platform specific functionality. For example load balancers and persistence volumes only work with the Google Compute provider at this time.
The Juju integration uses the Kubernetes null provider. This means external load balancers and storage can't be directly driven through Kubernetes config files at this time. We look forward to adding these capabilities to the charms.
More about the components the bundle deploys
Kubernetes master
The master controls the Kubernetes cluster. It manages for the worker nodes and provides the primary interface for control by the user.
Kubernetes minion
The minions are the servers that perform the work. Minions must communicate with the master and run the workloads that are assigned to them.
Flannel-docker
Flannel provides individual subnets for each machine in the cluster by creating a software defined networking.
Docker
An open platform for distributed applications for developers and sysadmins.
Etcd
Etcd persists state for Flannel and Kubernetes. It is a distributed key-value store with an http interface.
For further information on getting started with Juju
Juju has complete documentation with regard to setup, and cloud configuration on it's own documentation site.
Installing the kubectl outside of kubernetes-master unit
Download the Kubernetes release from: https://github.com/kubernetes/kubernetes/releases and extract the release, you can then just directly use the cli binary at ./kubernetes/platforms/linux/amd64/kubectl
You'll need the address of the kubernetes-master as environment variable :
juju status kubernetes-master/0
Grab the public-address there and export it as KUBERNETES_MASTER environment variable :
export KUBERNETES_MASTER=$(juju status --format=oneline kubernetes-master | grep kubernetes-master | cut -d' ' -f3):8080
And now you can run kubectl on the command line :
kubectl get no
See the kubectl documentation for more details of what can be done with the command line tool.
Hacking on the kubernetes-bundle and associated charms
The kubernetes-bundle is open source and available on github.com. If you want to get started developing on the bundle you can clone it from github.
git clone https://github.com/kubernetes/kubernetes.git
Go to the Getting started with Juju guide for more information about the bundle or charms.
How to contribute
Send us pull requests! We'll send you a cookie if they include tests and docs.
Current and Most Complete Information
The charms and bundles are in the kubernetes repository in github.
More information about the Kubernetes project or check out the Kubernetes Documentation for more details about the Kubernetes concepts and terminology.
Having a problem? Check the Kubernetes issues database for related issues.