John Mulhausen
2.7 KiB
layout, title
| layout | title |
|---|---|
| docwithnav | Getting started with config files. |
Getting started with config files.
In addition to the imperative style commands described elsewhere, Kubernetes supports declarative YAML or JSON configuration files. Often times config files are preferable to imperative commands, since they can be checked into version control and changes to the files can be code reviewed, producing a more robust, reliable and archival system.
Running a container from a pod configuration file
{% highlight console %} {% raw %} $ cd kubernetes $ kubectl create -f ./pod.yaml {% endraw %} {% endhighlight %}
Where pod.yaml contains something like:
{% highlight yaml %} {% raw %} apiVersion: v1 kind: Pod metadata: name: nginx labels: app: nginx spec: containers:
- name: nginx
image: nginx
ports:
- containerPort: 80 {% endraw %} {% endhighlight %}
You can see your cluster's pods:
{% highlight console %} {% raw %} $ kubectl get pods {% endraw %} {% endhighlight %}
and delete the pod you just created:
{% highlight console %} {% raw %} $ kubectl delete pods nginx {% endraw %} {% endhighlight %}
Running a replicated set of containers from a configuration file
To run replicated containers, you need a Replication Controller. A replication controller is responsible for ensuring that a specific number of pods exist in the cluster.
{% highlight console %} {% raw %} $ cd kubernetes $ kubectl create -f ./replication.yaml {% endraw %} {% endhighlight %}
Where replication.yaml contains:
{% highlight yaml %} {% raw %} apiVersion: v1 kind: ReplicationController metadata: name: nginx spec: replicas: 3 selector: app: nginx template: metadata: name: nginx labels: app: nginx spec: containers: - name: nginx image: nginx ports: - containerPort: 80 {% endraw %} {% endhighlight %}
To delete the replication controller (and the pods it created):
{% highlight console %} {% raw %} $ kubectl delete rc nginx {% endraw %} {% endhighlight %}