Constant rama::telemetry::opentelemetry::semantic_conventions::attribute::K8S_CLUSTER_UID

pub const K8S_CLUSTER_UID: &'static str;

A pseudo-ID for the cluster, set to the UID of the kube-system namespace.

K8s doesn't have support for obtaining a cluster ID. If this is ever added, we will recommend collecting the k8s.cluster.uid through the official APIs. In the meantime, we are able to use the uid of the kube-system namespace as a proxy for cluster ID. Read on for the rationale.

Every object created in a K8s cluster is assigned a distinct UID. The kube-system namespace is used by Kubernetes itself and will exist for the lifetime of the cluster. Using the uid of the kube-system namespace is a reasonable proxy for the K8s ClusterID as it will only change if the cluster is rebuilt. Furthermore, Kubernetes UIDs are UUIDs as standardized by ISO/IEC 9834-8 and ITU-T X.667. Which states:

> If generated according to one of the mechanisms defined in Rec. ITU-T X.667 | ISO/IEC 9834-8, a UUID is either guaranteed to be different from all other UUIDs generated before 3603 A.D., or is extremely likely to be different (depending on the mechanism chosen).

Therefore, UIDs between clusters should be extremely unlikely to conflict.

Examples

• 218fc5a9-a5f1-4b54-aa05-46717d0ab26d