website/content/en/docs/tutorials/configuration/configure-redis-using-configmap.md

reviewers	title	content_template
eparis pmorie	Configuring Redis using a ConfigMap	templates/tutorial

{{% capture overview %}}

This page provides a real world example of how to configure Redis using a ConfigMap and builds upon the Configure Containers Using a ConfigMap task.

{{% /capture %}}

{{% capture objectives %}}

• Create a ConfigMap.
• Create a pod specification using the ConfigMap.
• Create the pod.
• Verify that the configuration was correctly applied.

{{% /capture %}}

{{% capture prerequisites %}}

• {{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
• Understand Configure Containers Using a ConfigMap.

{{% /capture %}}

{{% capture lessoncontent %}}

Real World Example: Configuring Redis using a ConfigMap

You can follow the steps below to configure a Redis cache using data stored in a ConfigMap.

First create a ConfigMap from the redis-config file:

{{< codenew file="pods/config/redis-config" >}}

curl -OL https://k8s.io/examples/pods/config/redis-config
kubectl create configmap example-redis-config --from-file=redis-config

configmap/example-redis-config created

Examine the created ConfigMap:

kubectl get configmap example-redis-config -o yaml

apiVersion: v1
data:
  redis-config: |
    maxmemory 2mb
    maxmemory-policy allkeys-lru    
kind: ConfigMap
metadata:
  creationTimestamp: 2016-03-30T18:14:41Z
  name: example-redis-config
  namespace: default
  resourceVersion: "24686"
  selfLink: /api/v1/namespaces/default/configmaps/example-redis-config
  uid: 460a2b6e-f6a3-11e5-8ae5-42010af00002

Now create a pod specification that uses the config data stored in the ConfigMap:

{{< codenew file="pods/config/redis-pod.yaml" >}}

Create the pod:

kubectl create -f https://k8s.io/examples/pods/config/redis-pod.yaml

In the example, the config volume is mounted at /redis-master. It uses path to add the redis-config key to a file named redis.conf. The file path for the redis config, therefore, is /redis-master/redis.conf. This is where the image will look for the config file for the redis master.

Use kubectl exec to enter the pod and run the redis-cli tool to verify that the configuration was correctly applied:

kubectl exec -it redis redis-cli
127.0.0.1:6379> CONFIG GET maxmemory
1) "maxmemory"
2) "2097152"
127.0.0.1:6379> CONFIG GET maxmemory-policy
1) "maxmemory-policy"
2) "allkeys-lru"

{{% /capture %}}

{{% capture whatsnext %}}

• Learn more about ConfigMaps.

{{% /capture %}}