*** PLEASE NOTE: This document applies to the HEAD of the source
tree only. If you are using a released version of Kubernetes, you almost
certainly want the docs that go with that version.
Documentation for specific releases can be found at
[releases.k8s.io](http://releases.k8s.io).
## Installing a Kubernetes Master Node via Docker
We'll begin by setting up the master node. For the purposes of illustration, we'll assume that the IP of this machine is ```${MASTER_IP}```
There are two main phases to installing the master:
* [Setting up ```flanneld``` and ```etcd```](#setting-up-flanneld-and-etcd)
* [Starting the Kubernetes master components](#starting-the-kubernetes-master)
## Setting up flanneld and etcd
### Setup Docker-Bootstrap
We're going to use ```flannel``` to set up networking between Docker daemons. Flannel itself (and etcd on which it relies) will run inside of
Docker containers themselves. To achieve this, we need a separate "bootstrap" instance of the Docker daemon. This daemon will be started with
```--iptables=false``` so that it can only run containers with ```--net=host```. That's sufficient to bootstrap our system.
Run:
```sh
sudo sh -c 'docker -d -H unix:///var/run/docker-bootstrap.sock -p /var/run/docker-bootstrap.pid --iptables=false --ip-masq=false --bridge=none --graph=/var/lib/docker-bootstrap 2> /var/log/docker-bootstrap.log 1> /dev/null &'
```
_Important Note_:
If you are running this on a long running system, rather than experimenting, you should run the bootstrap Docker instance under something like SysV init, upstart or systemd so that it is restarted
across reboots and failures.
### Startup etcd for flannel and the API server to use
Run:
```
sudo docker -H unix:///var/run/docker-bootstrap.sock run --net=host -d gcr.io/google_containers/etcd:2.0.9 /usr/local/bin/etcd --addr=127.0.0.1:4001 --bind-addr=0.0.0.0:4001 --data-dir=/var/etcd/data
```
Next, you need to set a CIDR range for flannel. This CIDR should be chosen to be non-overlapping with any existing network you are using:
```sh
sudo docker -H unix:///var/run/docker-bootstrap.sock run --net=host gcr.io/google_containers/etcd:2.0.9 etcdctl set /coreos.com/network/config '{ "Network": "10.1.0.0/16" }'
```
### Set up Flannel on the master node
Flannel is a network abstraction layer build by CoreOS, we will use it to provide simplified networking between our Pods of containers.
Flannel re-configures the bridge that Docker uses for networking. As a result we need to stop Docker, reconfigure its networking, and then restart Docker.
#### Bring down Docker
To re-configure Docker to use flannel, we need to take docker down, run flannel and then restart Docker.
Turning down Docker is system dependent, it may be:
```sh
sudo /etc/init.d/docker stop
```
or
```sh
sudo systemctl stop docker
```
or it may be something else.
#### Run flannel
Now run flanneld itself:
```sh
sudo docker -H unix:///var/run/docker-bootstrap.sock run -d --net=host --privileged -v /dev/net:/dev/net quay.io/coreos/flannel:0.3.0
```
The previous command should have printed a really long hash, copy this hash.
Now get the subnet settings from flannel:
```
sudo docker -H unix:///var/run/docker-bootstrap.sock exec cat /run/flannel/subnet.env
```
#### Edit the docker configuration
You now need to edit the docker configuration to activate new flags. Again, this is system specific.
This may be in ```/etc/default/docker``` or ```/etc/systemd/service/docker.service``` or it may be elsewhere.
Regardless, you need to add the following to the docker command line:
```sh
--bip=${FLANNEL_SUBNET} --mtu=${FLANNEL_MTU}
```
#### Remove the existing Docker bridge
Docker creates a bridge named ```docker0``` by default. You need to remove this:
```sh
sudo /sbin/ifconfig docker0 down
sudo brctl delbr docker0
```
You may need to install the ```bridge-utils``` package for the ```brctl``` binary.
#### Restart Docker
Again this is system dependent, it may be:
```sh
sudo /etc/init.d/docker start
```
it may be:
```sh
systemctl start docker
```
## Starting the Kubernetes Master
Ok, now that your networking is set up, you can startup Kubernetes, this is the same as the single-node case, we will use the "main" instance of the Docker daemon for the Kubernetes components.
```sh
sudo docker run --net=host -d -v /var/run/docker.sock:/var/run/docker.sock gcr.io/google_containers/hyperkube:v0.18.2 /hyperkube kubelet --api_servers=http://localhost:8080 --v=2 --address=0.0.0.0 --enable_server --hostname_override=127.0.0.1 --config=/etc/kubernetes/manifests-multi
```
### Also run the service proxy
```sh
sudo docker run -d --net=host --privileged gcr.io/google_containers/hyperkube:v0.18.2 /hyperkube proxy --master=http://127.0.0.1:8080 --v=2
```
### Test it out
At this point, you should have a functioning 1-node cluster. Let's test it out!
Download the kubectl binary
([OS X](http://storage.googleapis.com/kubernetes-release/release/v0.18.2/bin/darwin/amd64/kubectl))
([linux](http://storage.googleapis.com/kubernetes-release/release/v0.18.2/bin/linux/amd64/kubectl))
List the nodes
```sh
kubectl get nodes
```
This should print:
```
NAME LABELS STATUS
127.0.0.1 kubernetes.io/hostname=127.0.0.1 Ready
```
If the status of the node is ```NotReady``` or ```Unknown``` please check that all of the containers you created are successfully running.
If all else fails, ask questions on IRC at #google-containers.
### Next steps
Move on to [adding one or more workers](worker.md)
[]()