A Kubernetes cluster with Heat

These Heat templates will deploy an N-node Kubernetes cluster, where N is the value of the number_of_minions parameter you specify when creating the stack.

The resulting cluster has a network configuration similar to that produced by the Vagrant configuration distributed with Kubernetes: an overlay network between the minions provides a unified address space across the minions, such that any Docker container can contact any other Docker container directly, regardless of the host on which they are running.

The Kubernetes cluster created by these templates is able to successfully run the guestbook example.

The cluster is based on Fedora 20, and makes use of the walters/atomic-next COPR repository.

NB: Fedora 20 initially shipped with a kernel that does not have the necessary support for vxlan to work correctly. If you are using this image you will need to reboot your minions in order for things to work correctly. You should create an updated Fedora 20 image with a newer kernel.

These templates are designed to work with the Icehouse version of Heat, with https://review.openstack.org/#/c/121139/ applied (this corrects a bug with template validation when using the "Fn::Join" function).

Creating the stack

Creating an environment file local.yaml with parameters specific to your environment:

parameters:
  ssh_key_name: lars
  external_network_id: 028d70dd-67b8-4901-8bdd-0c62b06cce2d
  dns_nameserver: 192.168.200.1

And then create the stack, referencing that environment file:

heat stack-create -f kubecluster.yaml -e local.yaml my-kube-cluster

You must provide values for:

• ssh_key_name
• external_network_id

You will probably need to override the server_image default value, as well.

Interacting with Kubernetes

NB: You will be able to log into the servers before Kubernetes is ready; you can tail the /var/log/cloud-init.log file to see when the software install and configuration is complete.

You can get the ip address of the Kubernetes master using the heat output-show command:

$ heat output-show my-kube-cluster kube_master
"192.168.200.86"

You can ssh into that server as the fedora user:

$ ssh fedora@192.168.200.86

And once logged in you can run kubecfg, etc:

$ kubecfg list minions
Minion identifier
----------
10.0.0.4
10.0.0.5