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Using Port Forwarding to Access Applications in a Cluster |
{% capture overview %}
This page shows how to use kubectl port-forward
to connect to a Redis
server running in a Kubernetes cluster. This type of connection can be useful
for database debugging.
{% endcapture %}
{% capture prerequisites %}
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{% include task-tutorial-prereqs.md %}
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Install redis-cli.
{% endcapture %}
{% capture steps %}
Creating a pod to run a Redis server
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Create a pod:
kubectl create -f http://k8s.io/docs/tasks/access-application-cluster/redis-master.yaml
The output of a successful command verifies that the pod was created:
pod "redis-master" created
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Check to see whether the pod is running and ready:
kubectl get pods
When the pod is ready, the output displays a STATUS of Running:
NAME READY STATUS RESTARTS AGE redis-master 2/2 Running 0 41s
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Verify that the Redis server is running in the pod and listening on port 6379:
{% raw %} kubectl get pods redis-master --template='{{(index (index .spec.containers 0).ports 0).containerPort}}{{"\n"}}' {% endraw %}
The output displays the port:
6379
Forward a local port to a port on the pod
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Forward port 6379 on the local workstation to port 6379 of redis-master pod:
kubectl port-forward redis-master 6379:6379
The output is similar to this:
I0710 14:43:38.274550 3655 portforward.go:225] Forwarding from 127.0.0.1:6379 -> 6379 I0710 14:43:38.274797 3655 portforward.go:225] Forwarding from [::1]:6379 -> 6379
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Start the Redis command line interface:
redis-cli
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At the Redis command line prompt, enter the
ping
command:127.0.0.1:6379>ping
A successful ping request returns PONG.
{% endcapture %}
{% capture discussion %}
Discussion
Connections made to local port 6379 are forwarded to port 6379 of the pod that is running the Redis server. With this connection in place you can use your local workstation to debug the database that is running in the pod.
{% endcapture %}
{% capture whatsnext %} Learn more about kubectl port-forward. {% endcapture %}
{% include templates/task.md %}