Host endpoint

4 MINUTE READ

A host endpoint resource (HostEndpoint) represents one or more real or virtual interfaces attached to a host that is running Calico. It enforces Calico policy on the traffic that is entering or leaving the host’s default network namespace through those interfaces.

  • A host endpoint with interfaceName: * represents all of a host’s real or virtual interfaces.

  • A host endpoint for one specific real interface is configured by interfaceName: <name-of-that-interface>, for example interfaceName: eth0, or by leaving interfaceName empty and including one of the interface’s IPs in expectedIPs.

Each host endpoint may include a set of labels and list of profiles that Calico will use to apply policy to the interface.

For calicoctl commands that specify a resource type on the CLI, the following aliases are supported (all case insensitive): hostendpoint, hostendpoints, hep, heps.

Default behavior of external traffic to/from host

If a host endpoint is created and network policy is not in place, the Calico default is to deny traffic to/from that endpoint (except for traffic allowed by failsafe rules). For a named host endpoint (i.e. a host endpoint representing a specific interface), Calico blocks traffic only to/from the interface specified in the host endpoint. Traffic to/from other interfaces is ignored. For a wildcard host endpoint (i.e. a host endpoint representing all of a host’s interfaces), Calico blocks traffic to/from all interfaces on the host (except for traffic allowed by failsafe rules).

However, profiles can be used in conjunction with host endpoints to modify default behavior of external traffic to/from the host in the absence of network policy. Calico provides a default profile resource named projectcalico-default-allow that consists of allow-all ingress and egress rules. Host endpoints with the projectcalico-default-allow profile attached will have “allow-all” semantics instead of “deny-all” in the absence of policy.

Note: If you have custom iptables rules, using host endpoints with allow-all rules (with no policies) will accept all traffic and therefore bypass those custom rules.

Auto host endpoints specify the projectcalico-default-allow profile so they behave similary to pod workload endpoints.

Important: When rendering security rules on other hosts, Calico uses the expectedIPs field to resolve label selectors to IP addresses. If the expectedIPs field is omitted then security rules that use labels will fail to match this endpoint.

Host to local workload traffic

Traffic from a host to its workload endpoints (e.g. Kubernetes pods) is always allowed, despite any policy in place. This ensures that kubelet liveness and readiness probes always work.

Sample YAML

apiVersion: projectcalico.org/v3
kind: HostEndpoint
metadata:
  name: some.name
  labels:
    type: production
spec:
  interfaceName: eth0
  node: myhost
  expectedIPs:
  - 192.168.0.1
  - 192.168.0.2
  profiles:
  - profile1
  - profile2
  ports:
  - name: some-port
    port: 1234
    protocol: TCP
  - name: another-port
    port: 5432
    protocol: UDP

Host endpoint definition

Metadata

Field Description Accepted Values Schema
name The name of this hostEndpoint. Required. Alphanumeric string with optional ., _, or -. string
labels A set of labels to apply to this endpoint.   map

Spec

Field Description Accepted Values Schema Default
node The name of the node where this HostEndpoint resides.   string  
interfaceName Either * or the name of the specific interface on which to apply policy.   string  
expectedIPs The expected IP addresses associated with the interface. Valid IPv4 or IPv6 address list  
profiles The list of profiles to apply to the endpoint.   list  
ports List of named ports that this workload exposes.   List of EndpointPorts  

EndpointPort

An EndpointPort associates a name with a particular TCP/UDP/SCTP port of the endpoint, allowing it to be referenced as a named port in policy rules.

Field Description Accepted Values Schema Default
name The name to attach to this port, allowing it to be referred to in policy rules. Names must be unique within an endpoint.   string  
protocol The protocol of this named port. TCP, UDP, SCTP string  
port The workload port number. 1-65535 int  

Note: On their own, EndpointPort entries don’t result in any change to the connectivity of the port. They only have an effect if they are referred to in policy.

Supported operations

Datastore type Create/Delete Update Get/List Notes
etcdv3 Yes Yes Yes  
Kubernetes API server Yes Yes Yes