How are pods and services named and deployed with AKO?

Detail

Lets assume this sample YAML:

apiVersion: asdb.aerospike.com/v1beta1
kind: AerospikeCluster
metadata:
 name: aerocluster
 namespace: aerospike

spec:
 size: 2
 image: aerospike/aerospike-server-enterprise:6.2.0.3

 storage:
   volumes:
     - name: workdir
       aerospike:
         path: /opt/aerospike
       source:
         persistentVolume:
           storageClass: gp2
           volumeMode: Filesystem
           size: 1Gi
     - name: test
       aerospike:
         path: /aerospike/dev/xvdf_test
       source:
         persistentVolume:
           storageClass: gp2
           volumeMode: Block
           size: 5Gi
     - name: aerospike-config-secret
       source:
         secret:
           secretName: aerospike-secret
       aerospike:
         path: /etc/aerospike/secret

 podSpec:
   multiPodPerHost: false
 rackConfig:
   namespaces:
     - test
   racks:
     - id: 1
     - id: 2

 aerospikeAccessControl:
   users:
     - name: admin
       secretName: auth-secret
       roles:
         - sys-admin
         - user-admin
         - read-write
 aerospikeConfig:
   service:
     feature-key-file: /etc/aerospike/secret/features.conf
   security: {}
   network:
     service:
       port: 3000
     fabric:
       port: 3001
     heartbeat:
       port: 3002

   namespaces:
     - name: test
       memory-size: 3000000000
       replication-factor: 2
       storage-engine:
         type: device
         devices:
           - /aerospike/dev/xvdf_test

Answer

Our AerospikeCluster name is defined by the metadata.name field:

kind: AerospikeCluster
metadata:
 name: aerocluster

If using rack-aware, like we are in the YAML, then each rack will be created in its own statefulset. If racks are not defined then the default behavior will be a single rack of rack 0.

rackConfig:
   namespaces:
     - test
   racks:
     - id: 1
     - id: 2

$ kubectl get statefulset -n aerospike
NAME                            READY  AGE
statefulset.apps/aerocluster-1  1/1    2d18h
statefulset.apps/aerocluster-2  1/1    2d18h

By design, each Pod in the StatefulSet will be assigned an integer ordinal, that is unique over the Set. By default, pods will be assigned ordinals from 0 up through N-1.

Putting this together we would have the following for a pod name:

Cluster Name + Rack ID + pod integer ordinal
aerocluster + 1 + 0 (first pod in statefulset)

$ kubectl get pods -n aerospike
NAME                 READY  STATUS   RESTARTS  AGE
pod/aerocluster-1-0  2/2    Running  0         2d18h
pod/aerocluster-2-0  2/2    Running  0         2d18h

If we want to access the pod by its hostname through DNS we can take this a step further. Kubernetes will assign DNS records to services and pods with the following schemas:

<pod_name>.<service>
<pod_name>.<service>.<namespace>

 <pod_name>.<service>.<namespace>.svc.cluster.local

By default, AKO will create the service name using the cluster name in the metadata.name field of the YAML if multiPodPerHost=false.

$ kubectl get service -n aerospike
NAME                     TYPE       CLUSTER-IP      EXTERNAL-IP  PORT(S)         AGE
service/aerocluster      ClusterIP  None            <none>       3000/TCP        2d18h

Translating this to our examples above would have the following resolvable hostnames for our aerocluster-1-0 pod:

aerocluster-1-0.aerocluster
aerocluster-1-0.aerocluster.aerospike
aerocluster-1-0.aerocluster.aerospike.svc.cluster.local

Notes

• https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/#pod-identity
• https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/

Applies To Earliest Version

Applies To Latest Version