Introduction

MicroK8s exposes several ports, and the one people usually mean by “the default port” is the Kubernetes API server on 16443. You can change that port by editing the API server arguments and restarting MicroK8s, but you should do it only if you really mean the control-plane API port. If your actual goal is to expose an application on another port, you probably want a Service, NodePort, LoadBalancer, or ingress rule instead.

Know Which Port You Are Changing

MicroK8s has multiple network-facing components. The commonly discussed one is the secure Kubernetes API server port. Changing it affects:

• local kubectl access
• CI or automation that talks to the cluster
• firewall rules
• any kubeconfig files that point to the cluster

So the first step is to confirm that you really need to move the API endpoint instead of a workload endpoint.

Where the API Server Port Is Defined

MicroK8s stores the API server arguments in this file:

/var/snap/microk8s/current/args/kube-apiserver

In a default installation, you will usually find a line like:

--secure-port=16443

Change that value to the port you want.

Example Change

Open the file with root privileges and edit the secure-port setting.

sudo nano /var/snap/microk8s/current/args/kube-apiserver

Update the relevant line, for example:

--secure-port=17443

Then restart MicroK8s so the API server picks up the new setting.

sudo snap restart microk8s

After restart, confirm the cluster is healthy:

microk8s status --wait-ready

Update Client Configuration Too

Changing the API server port is only half the job. Clients still need to know where the cluster moved.

If you use the generated kubeconfig, refresh or edit it so the server entry points to the new port. A typical server value looks like this:

server: https://127.0.0.1:17443

Any CI job, local shell alias, or external machine using the old 16443 value must be updated as well.

Firewall and Network Considerations

If a firewall was allowing 16443, it now needs to allow the new port and possibly remove the old one. If the cluster is being accessed remotely, check security groups, host firewalls, VPN policy, or reverse-proxy configuration.

Port changes also matter when documentation or scripts assume the default endpoint. A control-plane port change is operationally small on one machine but surprisingly disruptive in automation.

When This Is the Wrong Fix

A lot of MicroK8s questions are really about exposing an application or avoiding conflict with another local service. In those cases, changing the API server port is often unnecessary.

Examples:

• to expose a Kubernetes app, use a Service or ingress
• to publish a workload on a host port, use a NodePort or host networking where appropriate
• to access the dashboard or registry add-on, configure those services directly instead of moving the whole API server

Changing the control-plane port should be the exception, not the first move.

Common Pitfalls

The biggest pitfall is changing --secure-port and forgetting to update kubeconfig files. The cluster may be healthy while every client still fails to connect.

Another mistake is editing the API server arguments when the real problem is an application service port collision. That adds control-plane churn without solving the workload issue cleanly.

Developers also forget firewall rules. Moving the port locally is easy; remembering all the network paths that depended on the old one is harder.

Finally, avoid unsupported drift unless you need it. The more you diverge from default ports, the more operational context every future maintainer must remember.

Summary

• The MicroK8s API server commonly listens on 16443, configured through /var/snap/microk8s/current/args/kube-apiserver.
• Change --secure-port only if you really mean to move the Kubernetes API endpoint.
• Restart MicroK8s after editing the file and verify cluster readiness.
• Update kubeconfig files, automation, and firewall rules to match the new port.
• If your goal is exposing an app, use Kubernetes service mechanisms instead of changing the control-plane port.