Configuring Redis using a ConfigMap
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.
Objectives
- Create a
kustomization.yaml
file containing:- a ConfigMap generator
- a Pod resource config using the ConfigMap
- Apply the directory by running
kubectl apply -k ./
- Verify that the configuration was correctly applied.
Before you begin
You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using Minikube, or you can use one of these Kubernetes playgrounds:
To check the version, enter kubectl version
.
- The example shown on this page works with
kubectl
1.14 and above. - Understand Configure Containers Using a ConfigMap.
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 kustomization.yaml
containing a ConfigMap from the redis-config
file:
pods/config/redis-config
|
---|
maxmemory 2mb
maxmemory-policy allkeys-lru
|
curl -OL https://k8s.io/examples/pods/config/redis-config
cat <<EOF >./kustomization.yaml
configMapGenerator:
- name: example-redis-config
files:
- redis-config
EOF
Add the pod resource config to the kustomization.yaml
:
pods/config/redis-pod.yaml
|
---|
|
curl -OL https://raw.githubusercontent.com/kubernetes/website/master/content/en/examples/pods/config/redis-pod.yaml
cat <<EOF >>./kustomization.yaml
resources:
- redis-pod.yaml
EOF
Apply the kustomization directory to create both the ConfigMap and Pod objects:
kubectl apply -k .
Examine the created objects by
> kubectl get -k .
NAME DATA AGE
configmap/example-redis-config-dgh9dg555m 1 52s
NAME READY STATUS RESTARTS AGE
pod/redis 1/1 Running 0 52s
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"
Delete the created pod:
kubectl delete pod redis
What's next
- Learn more about ConfigMaps.
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