Deploying Atomic + Kubernetes with Heat
These Heat templates will deploy a cluster of Nova instances running Kubernetes on top of Project Atomic. The cluster uses Flannel to provide an overlay network connecting pods deployed on different nodes.
You can determine the initial size of the cluster via a configuration parameter when you deploy it, and the cluster will scale dynamically (up to a specified maximum size) due to CPU load on the Kubernetes nodes.
You should deploy some simple stacks in your environment to ensure that Heat is configured correctly before attempting to use these templates.
These templates are known to work with RHEL Atomic 7.1.2 and Fedora 22 Atomic.
Creating the stack
These templates define several parameters that can be used to
configure the stack; for details see the
parameters section of
kubecluster.yaml. While many of the parameters have reasonable
defaults, you will need to provide values for:
ssh_key_name-- the name of an SSH key already installed in Nova that will be used for accessing your Kubernetes nodes.
server_image-- the name of an image in Glance that will be used to instantiate the nodes.
You may need to provide a value for:
dns_nameserver-- a nameserver that is reachable in your environment. This defaults to one of the public Google nameservers (18.104.22.168), which may not be accessible (or useful) in some internal environments.
To provide the parameter values to the template you will create an environment file that may look something like this:
parameters: ssh_key_name: lars server_image: fedora-atomic dns_nameserver: 192.168.122.1
You will provide this file via the
-e argument to
heat stack-create -f kubecluster.yaml -e params.yaml my-kube-cluster
Interacting with Kubernetes
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
$ ssh email@example.com
And once logged in you can run
kubectl to interact with the
$ kubectl get minions NAME LABELS STATUS 10.0.0.4 <none> Ready
You can log into your nodes using the
minion user as well. You
can get a list of node addresses by running:
$ heat output-show my-kube-cluster kube_minions_external [ "192.168.200.182" ]
The templates install some example Pod and Service descriptions into
/etc/kubernetes/examples. You can deploy this with the following
$ kubectl create -f /etc/kubernetes/examples/web.service $ kubectl create -f /etc/kubernetes/examples/web.replica
This will deploy a minimal webserver and a corresponding service. You
kubectl get pods and
kubectl get services to see the
results of these commands.
Copyright 2014 Lars Kellogg-Stedman firstname.lastname@example.org
Licensed under the Apache License, Version 2.0 (the "License"); you may not use these files except in compliance with the License. You may obtain a copy of the License at
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
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