Below is all replica sets in my kubernetes environments create by deployments (when using deployment, it will first create replica sets):
[root@master24 004-prometheus]# kubectl get rs --all-namespaces
NAMESPACE NAME DESIRED CURRENT READY AGE
dev test-ddd-1-0-4129700023 3 3 3 6d
dev test111-1-0-2606576459 3 3 3 6d
dev test2-1-0-568340644 3 3 0 6d
kube-system alertmanager-2876254624 0 0 0 12d
kube-system alertmanager-34609585 0 0 0 31d
kube-system alertmanager-646055916 1 1 1 12d
kube-system container-terminal-2048074043 1 1 1 26d
kube-system container-terminal-2798068035 0 0 0 26d
kube-system default-http-backend-2282004791 1 1 1 99d
kube-system elastic-hq-1088064035 0 0 0 62d
kube-system elastic-hq-143297398 1 1 1 32d
kube-system elastic-hq-2334099411 0 0 0 62d
kube-system elastic-hq-2453506004 0 0 0 62d
kube-system elastic-hq-963545625 0 0 0 35d
kube-system grafana-2729867605 1 1 1 32d
kube-system kibana-logging-2271207004 1 1 1 39d
kube-system kibana-logging-3117667162 0 0 0 65d
kube-system kube-dns-1277622866 1 1 1 103d
kube-system kube-dns-418314620 0 0 0 103d
kube-system kube-ops-view-2627512969 1 1 1 62d
kube-system kube-state-metrics-290271031 2 2 2 31d
kube-system kubernetes-dashboard-102631441 0 0 0 103d
kube-system kubernetes-dashboard-2251164715 0 0 0 102d
kube-system kubernetes-dashboard-2628062973 1 1 1 25d
kube-system kubernetes-dashboard-3038119623 0 0 0 102d
kube-system kubernetes-dashboard-4259055596 0 0 0 40d
kube-system kubernetes-dashboard-849151901 0 0 0 103d
kube-system nginx-ingress-controller-1663470174 0 0 0 65d
kube-system nginx-ingress-controller-2772479350 0 0 0 64d
kube-system nginx-ingress-controller-3812017923 4 4 4 32d
kube-system nginx-ingress-controller-878021172 0 0 0 99d
kube-system prometheus-core-1049380509 0 0 0 11d
kube-system prometheus-core-1057044748 0 0 0 11d
kube-system prometheus-core-124082880 0 0 0 12d
kube-system prometheus-core-1274300653 0 0 0 32d
kube-system prometheus-core-1496270586 0 0 0 10d
kube-system prometheus-core-2953594474 0 0 0 10d
kube-system prometheus-core-3816572233 1 1 1 10d
kube-system prometheus-core-87115933 0 0 0 22d
kube-system prometheus-core-87378077 0 0 0 31d
kube-system redmine-sqlite-1134748302 0 0 0 31d
kube-system redmine-sqlite-1236657579 1 1 1 31d
kube-system redmine-sqlite-2005852822 0 0 0 31d
kube-system redmine-sqlite-3063145196 0 0 0 31d
kube-system sonarqube-3729821934 0 0 0 31d
kube-system sonarqube-3857878650 0 0 0 31d
kube-system sonarqube-3908538607 1 1 1 30dFor some reason I need to analyze the name of rs and all names of rs contains some random digitals in the end, but the number of digitals is not fixed( it may be 8, 9 or 10). So the question is:
Does the the number of digitals is always be 8, 9 or 10, or it could be any number like 5 or 15?
Where do I found the naming rules of this?
Envrionment kubernets 1.6.8
If I found the correct line, then the name of a ReplicaSet is generated here: https://github.com/kubernetes/kubernetes/blob/16670f1a95a61434f8d6c96596a3c541b01fb8aa/pkg/controller/deployment/sync.go#L299
podTemplateSpecHash := fmt.Sprintf("%d", controller.ComputeHash(&newRSTemplate, d.Status.CollisionCount))
//...
Name: d.Name + "-" + rand.SafeEncodeString(podTemplateSpecHash),Where d is a deployment.
The random method is implemented like this:
// SafeEncodeString encodes s using the same characters as rand.String. This reduces the chances of bad words and
// ensures that strings generated from hash functions appear consistent throughout the API.
func SafeEncodeString(s string) string {
r := make([]rune, len(s))
for i, b := range []rune(s) {
r[i] = alphanums[(int(b) % len(alphanums))]
}
return string(r)
}
It looks to me, that the length of the random is based on the length of the podTemplateSpecHash, which is a value of type uint32. Here is the method signature of the hashing function:
func ComputeHash(template *v1.PodTemplateSpec, collisionCount *int32) uint32 {...}Therefore the maximum number of digits should be 10.