# NodePort Parameter Modification

## 1. API Server NodePort Range Modification

In the UK8S cluster, the APIServer related parameters are stored in the `/etc/kubernetes/apiserver` file on the Master node. Please perform the following operations on each Master node.

**Backup this configuration file** and modify the `--service-node-port-range` to the desired parameter in the file.

```
KUBE_API_ARGS=" --... \
                --... \
                --service-node-port-range=30000-32767 \
                --... \
                --..."
```

After the modification, restart the APIServer through `systemctl restart kube-apiserver`.

> ⚠️ If the Service in the cluster has been assigned a port outside the target NodePort Range, after modification, check the cluster events through `kubectl get event -A`, there will be a warning event similar to the following
> The warning event does not affect the use of this port. If you want to avoid this warning, you need to rebuild the Service.

```bash
# kubectl get event -A
NAMESPACE      LAST SEEN   TYPE      REASON             OBJECT                         MESSAGE
uk8s-monitor   79s         Warning   PortOutOfRange     service/grafana                Port 34840 is not within the port range 30000-32767; please recreate service
uk8s-monitor   78s         Warning   PortNotAllocated   service/grafana                Port 34840 is not allocated; repairing
```

## 2. Modify the node ip_local_port_range

Check the current system open port range, as follows:

```
# cat /proc/sys/net/ipv4/ip_local_port_range 
12000 65535
```

If you need to modify it, please change the `net.ipv4.ip_local_port_range` field in the `/etc/sysctl.conf` file.

```
net.ipv4.ip_local_port_range = 32768 60999
```

After the modification, execute `sysctl -p` to take the configuration into effect, and verify again:

```
# cat /proc/sys/net/ipv4/ip_local_port_range 
32768 60999
```