MeshService
This resource is experimental!
In Kubernetes, to take advantage of the automatic generation described below,
you need to set both control plane configuration variables KUMA_EXPERIMENTAL_SKIP_PERSISTED_VIPS
and KUMA_EXPERIMENTAL_GENERATE_MESH_SERVICES to "true" on the zone control
planes that use MeshServices.
MeshService is a new resource that represents what was previously expressed by
the Dataplane tag kuma.io/service. Kubernetes users should think about it as
the analog of a Kubernetes Service.
A basic example follows to illustrate the structure:
apiVersion: kuma.io/v1alpha1
kind: MeshService
metadata:
name: redis
namespace: kuma-system
labels:
team: db-operators
kuma.io/mesh: default
spec:
selector:
dataplaneTags:
app: redis
k8s.kuma.io/namespace: redis-system
ports:
- port: 6739
targetPort: 6739
appProtocol: tcp
- name: some-port
port: 16739
targetPort: target-port-from-container
appProtocol: tcp
The MeshService represents a destination for traffic from elsewhere in the mesh.
It defines which Dataplane objects serve this traffic as well as what ports
are available. It also holds information about which IPs and hostnames can be used
to reach this destination.
Zone types
How users interact with MeshServices will depend on the type of zone.
Kubernetes
On Kubernetes, Service already provides a number of the features provided by
MeshService. For this reason, Kuma generates MeshServices from Services and:
- reuses VIPs in the form of cluster IPs
- uses Kubernetes DNS names
In the vast majority of cases, Kubernetes users do not create MeshServices.
Universal
In universal zones, MeshServices need to be created manually for now. A
strategy of
automatically generating MeshService objects from Dataplanes is planned for
the future.
Hostnames
Because of various shortcomings, the existing VirtualOutbound does not work
with MeshService and is planned for phasing out. A new HostnameGenerator
resource was introduced to manage hostnames for
MeshServices.
Ports
The ports field lists the ports exposed by the Dataplanes that
the MeshService matches. targetPort can refer to a port directly or by the
name of the Dataplane port.
ports:
- name: redis-non-tls
port: 16739
targetPort: 6739
appProtocol: tcp