MicroShift is Developer Preview software only.
For more information about the support scope of Red Hat Developer Preview software, see Developer Preview Support Scope.Chapter 1. How configuration tools work
A YAML file customizes Red Hat build of MicroShift instances with your preferences, settings, and parameters.
1.1. Using a YAML configuration file
Red Hat build of MicroShift searches for a configuration file in the user-specific directory, ~/.microshift/config.yaml, then the system-wide /etc/microshift/config.yaml directory. You must create the configuration file and specify any settings that should override the defaults before starting Red Hat build of MicroShift.
1.1.1. Default settings
If you do not create a config.yaml file, the default values are used. The following example configuration contains the default settings. You must change any settings that should override the defaults before starting Red Hat build of MicroShift.
Default YAML file example
dns: baseDomain: microshift.example.com 1 network: clusterNetwork: - cidr: 10.42.0.0/16 2 serviceNetwork: - 10.43.0.0/16 3 serviceNodePortRange: 30000-32767 4 node: hostnameOverride: "" 5 nodeIP: "" 6 apiServer: subjectAltNames: [] 7 debugging: logLevel: "Normal" 8
- 1
- Base domain of the cluster. All managed DNS records will be subdomains of this base.
- 2
- A block of IP addresses from which Pod IP addresses are allocated.
- 3
- A block of virtual IP addresses for Kubernetes services.
- 4
- The port range allowed for Kubernetes services of type NodePort.
- 5
- The name of the node. The default value is the hostname.
- 6
- The IP address of the node. The default value is the IP address of the default route.
- 7
- Subject Alternative Names for API server certificates.
- 8
- Log verbosity. Valid values for this field are
Normal,Debug,Trace, orTraceAll.
Red Hat build of MicroShift only reads the configuration file on startup. Restart Red Hat build of MicroShift after changing any configuration settings to have them take effect.
1.2. Extending the port range for NodePort services
The serviceNodePortRange setting allows the extension of the port range available to NodePort services. This option is useful when specific standard ports under the 30000-32767 need to be exposed. For example, your device needs to expose the 1883/tcp MQ Telemetry Transport (MQTT) port on the network because some client devices cannot use a different port.
NodePorts can overlap with system ports, causing a malfunction of the system or Red Hat build of MicroShift.
Considerations when configuring the NodePort service ranges:
-
Do not create any NodePort service without an explicit
nodePortselection. In this case, the port is assigned randomly by thekube-apiserver. -
Do not create any NodePort service for any system service port, Red Hat build of MicroShift port, or other services you expose on your device
HostNetwork. - Table one specifies ports to avoid when extending the port range:
| Port | Description |
|---|---|
| 22/tcp | SSH port |
| 80/tcp | OpenShift Router HTTP endpoint |
| 443/tcp | OpenShift Router HTTPS endpoint |
| 1936/tcp | Metrics service for the openshift-router, not exposed today |
| 2379/tcp | etcd port |
| 2380/tcp | etcd port |
| 6443 | kubernetes API |
| 8445/tcp | openshift-route-controller-manager |
| 9537/tcp | cri-o metrics |
| 10250/tcp | kubelet |
| 10248/tcp | kubelet healthz port |
| 10259/tcp | kube scheduler |
