EVEREST-271 fix name starts with a digit

[oksana-grishchenko]

Fix CR names validation

Problem:
EVEREST-271 Database clusters with a name that starts with a digit, never go up

oxanagrishchenko@Oxanas-MacBook-Pro percona-everest-backend % kubectl get dbc -n percona-everest 
NAME                     SIZE   READY   STATUS         HOSTNAME                                                    AGE
1mysql                   2              initializing   1mysql-haproxy.percona-everest                              11m
1test-pg-cluster                        initializing   1test-pg-cluster-pgbouncer.percona-everest.svc              3m42s
1test-psmdb-cluster      1      1       initializing   1test-psmdb-cluster-rs0.percona-everest.svc.cluster.local   6m3s
2test-pg-cluster                        initializing   2test-pg-cluster-pgbouncer.percona-everest.svc              112s
3mysql-321123456789      2              initializing   3mysql-321123456789-haproxy.percona-everest                 4h31m
3mysql-3211234567890     2              initializing   3mysql-3211234567890-haproxy.percona-everest                4h34m
3mysql-32112345678909    2              initializing   3mysql-32112345678909-haproxy.percona-everest               4h35m
3mysql-321123456789093   2              initializing   3mysql-321123456789093-haproxy.percona-everest              4h46m
mysql-3211234567890123   2      2       ready          mysql-3211234567890123-haproxy.percona-everest              4h30m
test-pg-cluster          2      2       ready          test-pg-cluster-pgbouncer.percona-everest.svc               3m35s
test-psmdb-cluster       1      1       ready          test-psmdb-cluster-rs0.percona-everest.svc.cluster.local    5m35s
test-pxc-cluster2        2      2       ready          test-pxc-cluster2-haproxy.percona-everest                   4h38m

Cause:
from the pxc logs:

 ERROR   Reconciler error        {"controller": "perconaxtradbcluster-controller", "object": {"name":"1minimal-cluster",
"namespace":"percona-everest"}, "namespace": "percona-everest", "name": "1minimal-cluster", "reconcileID": 
"d0244667-3a9a-4d4c-99eb-71df0fca6fa2", "error": "PXC service upgrade error: Service \"1minimal-cluster-pxc\" is 
invalid: metadata.name: Invalid value: \"1minimal-cluster-pxc\": a DNS-1035 label must consist of lower case alphanumeric 
characters or '-', start with an alphabetic character, and end with an alphanumeric character (e.g. 'my-name',  or 'abc-123', 
regex used for validation is '[a-z]([-a-z0-9]*[a-z0-9])?')"

Solution:
Do not allow first symbol of the CR name to be a digit

CHECKLIST

Jira

• Is the Jira ticket created and referenced properly?

Tests

• Is an Integration test/test case added for the new feature/change?
• Are unit tests added where appropriate?