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| docwithnav | Connecting to applications: kubectl port-forward |
Connecting to applications: kubectl port-forward
kubectl port-forward forwards connections to a local port to a port on a pod. Its man page is available here. Compared to kubectl proxy, kubectl port-forward is more generic as it can forward TCP traffic while kubectl proxy can only forward HTTP traffic. This guide demonstrates how to use kubectl port-forward to connect to a Redis database, which may be useful for database debugging.
Creating a Redis master
{% highlight console %} {% raw %} $ kubectl create examples/redis/redis-master.yaml pods/redis-master {% endraw %} {% endhighlight %}
wait until the Redis master pod is Running and Ready,
{% highlight console %} {% raw %} $ kubectl get pods NAME READY STATUS RESTARTS AGE redis-master 2/2 Running 0 41s {% endraw %} {% endhighlight %}
Connecting to the Redis master[a]
The Redis master is listening on port 6397, to verify this,
{% highlight console %} {% raw %} $ kubectl get pods redis-master -t='{{(index (index .spec.containers 0).ports 0).containerPort}}{{"\n"}}' 6379 {% endraw %} {% endhighlight %}
then we forward the port 6379 on the local workstation to the port 6379 of pod redis-master,
{% highlight console %} {% raw %} $ kubectl port-forward redis-master 6379:6379 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 {% endraw %} {% endhighlight %}
To verify the connection is successful, we run a redis-cli on the local workstation,
{% highlight console %} {% raw %} $ redis-cli 127.0.0.1:6379> ping PONG {% endraw %} {% endhighlight %}
Now one can debug the database from the local workstation.