Configure Host Aliases and Pod DNS

Configure Host Aliases

The hostAliases field adds static hostname mappings to /etc/hosts in the Kubernetes pod that runs the corresponding SingleStore engine node. Each entry specifies an IP address and one or more hostnames.

spec:
  masterAggregatorSpec:
    hostAliases:
      - ip: 10.1.2.3
        hostnames:
          - broker-1.internal
          - broker-2.internal

Configure Pod DNS

The dnsConfig field configures DNS settings for the Kubernetes pods that run the corresponding type of SingleStore engine node. Supported subfields are nameservers, searches, and options.

spec:
  leafSpec:
    dnsConfig:
      nameservers:
        - 1.1.1.1
      searches:
        - corp.example
      options:
        - name: ndots
          value: "2"

For Kubernetes pods running SingleStore engine nodes, the Operator sets the DNS policy to ClusterFirst. You cannot override dnsPolicy in the MemsqlCluster custom resource. The Operator applies only the settings specified in dnsConfig; if you omit dnsConfig, it leaves the pod’s DNS configuration unchanged.

Configure Fields for Each Node Type

Configure hostAliases and dnsConfig under the corresponding node specification: masterAggregatorSpec, childAggregatorSpec, or leafSpec. Refer to Pod Scheduling for more information about scheduling attributes. For example:

apiVersion: memsql.com/v1alpha1
kind: MemsqlCluster
metadata:
  name: sdb-cluster
spec:
  masterAggregatorSpec:
    hostAliases:
      - ip: 10.1.2.3
        hostnames:
          - broker-1.internal
  childAggregatorSpec:
    dnsConfig:
      searches:
        - aggregator.corp.example
  leafSpec:
    hostAliases:
      - ip: 10.1.2.4
        hostnames:
          - broker-2.internal
    dnsConfig:
      searches:
        - leaf.corp.example

Apply the updated object definition file:

kubectl apply -f sdb-cluster.yaml