Endpoint Lifecycle

This section specifies the lifecycle of Cilium endpoints.

Every endpoint in Cilium is in one of the following states:

• restoring: The endpoint was started before Cilium started, and Cilium is restoring its networking configuration.

• waiting-for-identity: Cilium is allocating a unique identity for the endpoint.

• waiting-to-regenerate: The endpoint received an identity and is waiting for its networking configuration to be (re)generated.

• regenerating: The endpoint’s networking configuration is being (re)generated. This includes programming eBPF for that endpoint.

• ready: The endpoint’s networking configuration has been successfully (re)generated.

• disconnecting: The endpoint is being deleted.

• disconnected: The endpoint has been deleted.

The state of an endpoint can be queried using the cilium-dbg endpoint list and cilium-dbg endpoint get CLI commands.

While an endpoint is running, it transitions between the waiting-for-identity, waiting-to-regenerate, regenerating, and ready states. A transition into the waiting-for-identity state indicates that the endpoint changed its identity. A transition into the waiting-to-regenerate or regenerating state indicates that the policy to be enforced on the endpoint has changed because of a change in identity, policy, or configuration.

An endpoint transitions into the disconnecting state when it is being deleted, regardless of its current state.

Init Identity

In some situations, Cilium can’t determine the labels of an endpoint immediately when the endpoint is created, and therefore can’t allocate an identity for the endpoint at that point. Until the endpoint’s labels are known, Cilium temporarily associates a special single label reserved:init to the endpoint. When the endpoint’s labels become known, Cilium then replaces that special label with the endpoint’s labels and allocates a proper identity to the endpoint.

This may occur during endpoint creation in the following cases:

• Running Cilium with docker via libnetwork

• With Kubernetes when the Kubernetes API server is not available

• In etcd mode when the corresponding kvstore is not available

To allow traffic to/from endpoints while they are initializing, you can create policy rules that select the reserved:init label, and/or rules that allow traffic to/from the special init entity.

For instance, writing a rule that allows all initializing endpoints to receive connections from the host and to perform DNS queries may be done as follows:

k8s YAMLJSON

apiVersion: "cilium.io/v2"
kind: CiliumClusterwideNetworkPolicy
metadata:
  name: init
specs:
  - endpointSelector:
      matchLabels:
        "reserved:init": ""
    ingress:
    - fromEntities:
      - host
    egress:
    - toEntities:
      - all
      toPorts:
      - ports:
        - port: "53"
          protocol: UDP

Likewise, writing a rule that allows an endpoint to receive DNS queries from initializing endpoints may be done as follows:

k8s YAMLJSON

apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
metadata:
  name: "from-init"
spec:
  endpointSelector:
    matchLabels:
      app: myService
  ingress:
    - fromEntities:
      - init
    - toPorts:
      - ports:
        - port: "53"
          protocol: UDP

If any ingress (resp. egress) policy rules selects the reserved:init label, all ingress (resp. egress) traffic to (resp. from) initializing endpoints that is not explicitly allowed by those rules will be dropped. Otherwise, if the policy enforcement mode is never or default, all ingress (resp. egress) traffic is allowed to (resp. from) initializing endpoints. Otherwise, all ingress (resp. egress) traffic is dropped.

Lockdown Mode

If the Cilium agent option enable-lockdown-endpoint-on-policy-overflow is set to “true” Cilium will put an endpoint into “lockdown” if the policy map cannot accommodate all of the required policy map entries required (that is, the policy map for the endpoint is overflowing). Cilium will put the endpoint out of “lockdown” when it detects that the policy map is no longer overflowing. When an endpoint is locked down all network traffic, both egress and ingress, will be dropped. Cilium will log a warning that the endpoint has been locked down.

If this option is enabled, cluster operators should closely monitor the metric the bpf map pressure metric of the cilium_policy_* maps. See Policymap pressure and overflow for more details. They can use this metric to create an alert for increased memory pressure on the policy map as well as alert for a lockdown if enable-lockdown-endpoint-on-policy-overflow is set to “true” (any bpf_map_pressure above a value of 1.0).