Running Kubernetes Locally with No VM
Requirements
Linux
Not running Linux? Consider running Linux in a local virtual machine with vagrant, or on a cloud provider like Google Compute Engine
Docker
At least Docker
1.8.3+. Ensure the Docker daemon is running and can be contacted (try docker
ps). Some of the Kubernetes components need to run as root, which normally
works fine with docker.
etcd
You need an etcd in your path, please make sure it is installed and in your $PATH.
go
You need go at least 1.3+ in your path, please make sure it is installed and in your $PATH.
Starting the cluster
First, you need to download Kubernetes. Then open a separate tab of your terminal and run the following (since one needs sudo access to start/stop Kubernetes daemons, it is easier to run the entire script as root):
cd kubernetes
hack/local-up-cluster.sh
This will build and start a lightweight local cluster, consisting of a master and a single node. Type Control-C to shut it down.
You can use the cluster/kubectl.sh script to interact with the local cluster. hack/local-up-cluster.sh will print the commands to run to point kubectl at the local cluster.
Running a container
Your cluster is running, and you want to start running containers!
You can now use any of the cluster/kubectl.sh commands to interact with your local setup.
cluster/kubectl.sh get pods
cluster/kubectl.sh get services
cluster/kubectl.sh get deployments
cluster/kubectl.sh run my-nginx --image=nginx --replicas=2 --port=80
## begin wait for provision to complete, you can monitor the docker pull by opening a new terminal
sudo docker images
## you should see it pulling the nginx image, once the above command returns it
sudo docker ps
## you should see your container running!
exit
## end wait
## introspect Kubernetes!
cluster/kubectl.sh get pods
cluster/kubectl.sh get services
cluster/kubectl.sh get deployments
Running a user defined pod
Note the difference between a container
and a pod. Since you only asked for the former, Kubernetes will create a wrapper pod for you.
However you cannot view the nginx start page on localhost. To verify that nginx is running you need to run curl within the docker container (try docker exec).
You can control the specifications of a pod via a user defined manifest, and reach nginx through your browser on the port specified therein:
cluster/kubectl.sh create -f docs/user-guide/pod.yaml
Congratulations!
FAQs
I cannot reach service IPs on the network.
Some firewall software that uses iptables may not interact well with
kubernetes. If you have trouble around networking, try disabling any
firewall or other iptables-using systems, first. Also, you can check
if SELinux is blocking anything by running a command such as journalctl --since yesterday | grep avc.
By default the IP range for service cluster IPs is 10.0.. - depending on your docker installation, this may conflict with IPs for containers. If you find containers running with IPs in this range, edit hack/local-cluster-up.sh and change the service-cluster-ip-range flag to something else.
I changed Kubernetes code, how do I run it?
cd kubernetes
hack/build-go.sh
hack/local-up-cluster.sh
kubectl claims to start a container but get pods and docker ps don’t show it.
One or more of the Kubernetes daemons might’ve crashed. Tail the logs of each in /tmp.
$ ls /tmp/kube*.log
$ tail -f /tmp/kube-apiserver.log
The pods fail to connect to the services by host names
The local-up-cluster.sh script doesn’t start a DNS service. Similar situation can be found here. You can start a manually. Related documents can be found here