Conceptually, the operator's task is just to change the pod. As it
has no influence over the role the pod will take (either the master
or a replica), it shouldn't wait for the specific role.
This fixes at least one issue, where the pod running in a single-pod
cluster has been waited for forever by the operator expecting it to
have a wrong role (since Patroni callback assiging it the original
replica role has been killed after a quick promote by the next
callback.)
* move statefulset creation from cluster spec to the separate function
* sync cluster state with desired state;
* move out from arrays for cluster resources;
* recreate pods instead of deleting them in case of statefulset change
* check for master while creating cluster/updating pods
* simplify retryutil
* list pvc while listing resources
* name kubernetes resources with capital letter
* do rolling update in case of env variables change
introduce Pod events channel;
add parsing of the MaintenanceWindows section;
skip deleting Etcd key on cluster delete;
use external etcd host;
watch for tpr/pods in the namespace of the operator pod only;
Murat Kabilov
Oleksii Kliukin