cluster_name not populated in cassandra.yaml by k8ssandra-client

[dnugmanov]

Issue Description:

I've noticed that the k8ssandra-client does not fill the cluster_name field in cassandra.yaml. The ClusterInfo struct contains a field for the cluster name, but it doesn't seem to be used anywhere in the code. This leads to incorrect monitoring metrics from the exporter because it fills the cluster_name label according to the cassandra.yaml parameters.

Example:

❯ cassandra@damir-test-damir-test-dc-rack1-sts-0:/$ cat /etc/cassandra/cassandra.yaml | grep cluster_name
cluster_name: Test Cluster

❯ k get pods -n mynamespace -o yaml | grep CONFIG_FILE_DATA -A 1
  - name: CONFIG_FILE_DATA
    value: '{"cassandra-env-sh":{"___OMITTED:___"cluster-info":{"name":"damir-test","seeds":"damir-test-seed-service,damir-test-damir-test-dc-additional-seed-service"},___OMITTED:___}'

Expected Behavior:

I believe the cluster_name field in cassandra.yaml should be properly filled by the k8ssandra_client.

Additional Information:

k8ssandra-client version: v0.2.0

[dnugmanov]

resolved in #18