Kubernetes

Kubernetes is an open source implementation of container cluster management.

Kubernetes Design Document

Kubernetes can run anywhere!

However, initial development was done on GCE and so our instructions and scripts are built around that. If you make it work on other infrastructure please let us know and contribute instructions/code.

Contents

• Getting started on Google Compute Engine
• Running a local cluster
• Discussion and Community Support
• Hacking on Kubernetes

Getting started on Google Compute Engine

Prerequisites

1. You need a Google Cloud Platform account with billing enabled. Visit http://cloud.google.com/console for more details.

2. Make sure you can start up a GCE VM. At least make sure you can do the Create an instance part of the GCE Quickstart.

3. You must have Go (version 1.2 or later) installed: www.golang.org.

4. You must have the gcloud components installed.

5. Ensure that your gcloud components are up-to-date by running gcloud components update.

6. Get the Kubernetes source:

    git clone https://github.com/GoogleCloudPlatform/kubernetes.git
   

7. Setting up a cluster requires the htpasswd tool in order to hash a randomly generated password for accessing the API server. This is already installed on recent version of Mac OS X but on Linux you need to install it yourself. On Debian/Ubuntu you can do this with:

    sudo apt-get update
    sudo apt-get install apache2-utils
   

Setup

The setup script builds Kubernetes, then creates Google Compute Engine instances, firewall rules, and routes:

cd kubernetes
hack/dev-build-and-up.sh

Running a container (simple version)

Once you have your instances up and running, the build-go.sh script sets up your Go workspace and builds the Go components.

The cloudcfg.sh script spins up two containers, running Nginx and with port 80 mapped to 8080:

cd kubernetes
hack/build-go.sh
cluster/cloudcfg.sh -p 8080:80 run dockerfile/nginx 2 myNginx

To stop the containers:

cluster/cloudcfg.sh stop myNginx

To delete the containers:

cluster/cloudcfg.sh rm myNginx

Running a container (more complete version)

Assuming you've run hack/dev-build-and-up.sh and hack/build-go.sh:

cd kubernetes
cluster/cloudcfg.sh -c api/examples/pod.json create /pods

Where pod.json contains something like:

{
  "ID": "nginx",
  "desiredState": {
    "image": "dockerfile/nginx",
    "networkPorts": [{
      "containerPort": 80,
      "hostPort": 8080
    }]
  },
  "labels": {
    "name": "foo"
  }
}

Look in api/examples/ for more examples

Tearing down the cluster

cd kubernetes
cluster/kube-down.sh

Running locally

In a separate tab of your terminal, run:

cd kubernetes
hack/local-up.sh

This will build and start a lightweight local cluster, consisting of a master and a single minion. Type Control-C to shut it down. While it's running, you can use hack/localcfg.sh in place of cluster/cloudcfg.sh to talk to it.

Where to go next?

Detailed example application

Or fork and start hacking!

Community, discussion and support

If you have questions or want to start contributing please reach out. We don't bite!

The Kubernetes team is hanging out on IRC on the #google-containers room on freenode.net. We also have the google-containers Google Groups mailing list.

If you are a company and are looking for a more formal engagement with Google around Kubernetes and containers at Google as a whole, please fill out this form. and we'll be in touch.

Development

Hooks

# Before committing any changes, please link/copy these hooks into your .git
# directory. This will keep you from accidentally committing non-gofmt'd
# go code.
cd kubernetes
ln -s "../../hooks/prepare-commit-msg" .git/hooks/prepare-commit-msg
ln -s "../../hooks/commit-msg" .git/hooks/commit-msg

Unit tests

cd kubernetes
hack/test-go.sh

Coverage

cd kubernetes
go tool cover -html=target/c.out

Integration tests

# You need an etcd somewhere in your path.
# To get from head:
go get github.com/coreos/etcd
go install github.com/coreos/etcd
sudo ln -s "$GOPATH/bin/etcd" /usr/bin/etcd
# Or just use the packaged one:
sudo ln -s "$REPO_ROOT/target/bin/etcd" /usr/bin/etcd

cd kubernetes
hack/integration-test.sh

Keeping your development fork in sync

One time after cloning your forked repo:

git remote add upstream https://github.com/GoogleCloudPlatform/kubernetes.git

Then each time you want to sync to upstream:

git fetch upstream
git rebase upstream/master

Regenerating the documentation

cd kubernetes/api
sudo docker build -t kubernetes/raml2html .
sudo docker run --name="docgen" kubernetes/raml2html
sudo docker cp docgen:/data/kubernetes.html .