Annotations are used in Ingress Controllers to configure features that are not covered by the Kubernetes Ingress API.
Some of the features that have been historically configured via annotations are supported as first-class features in Contour's IngressRoute API, which provides a more robust configuration interface over annotations.
However, Contour still supports a number of annotations on the Ingress resources.
kubernetes.io/ingress.class: The Ingress class that should interpret and serve the Ingress. If not set, then all Ingress controllers serve the Ingress. If specified askubernetes.io/ingress.class: contour, then Contour serves the Ingress. If any other value, Contour ignores the Ingress definition. You can override the default classcontourwith the--ingress-class-nameflag at runtime. This can be useful while you are migrating from another controller, or if you need multiple instances of Contour.ingress.kubernetes.io/force-ssl-redirect: Requires TLS/SSL for the Ingress to Envoy by setting the Envoy virtual host option require_tlskubernetes.io/ingress.allow-http: Instructs Contour to not create an Envoy HTTP route for the virtual host. The Ingress exists only for HTTPS requests. Specify"false"for Envoy to mark the endpoint as HTTPS only. All other values are ignored.
contour.heptio.com/request-timeout: The Envoy HTTP route timeout, specified as a golang duration. By default, Envoy has a 15 second timeout for a backend service to respond. Set this toinfinityto specify that Envoy should never timeout the connection to the backend. Note that the value0s/ zero has special semantics for Envoy.contour.heptio.com/retry-on: The conditions for Envoy to retry a request. See also possible values and their meanings forretry-on.contour.heptio.com/num-retries: The maximum number of retries Envoy should make before abandoning and returning an error to the client. Applies only ifcontour.heptio.com/retry-onis specified.contour.heptio.com/per-try-timeout: The timeout per retry attempt, if there should be one. Applies only ifcontour.heptio.com/retry-onis specified.contour.heptio.com/tls-minimum-protocol-version: The minimum TLS protocol version the TLS listener should support.contour.heptio.com/websocket-routes: The routes supporting websocket protocol, the annotation value contains a list of route paths separated by a comma that must match with the ones defined in theIngressdefinition. Defaults to Envoy's default behavior which isuse_websockettofalse. The IngressRoute API has first-class support for websockets.
A Kubernetes Service maps to an Envoy Cluster. Envoy clusters have many settings to control specific behaviors. These annotations allow access to some of those settings.
contour.heptio.com/max-connections: The maximum number of connections that a single Envoy instance allows to the Kubernetes Service; defaults to 1024.contour.heptio.com/max-pending-requests: The maximum number of pending requests that a single Envoy instance allows to the Kubernetes Service; defaults to 1024.contour.heptio.com/max-requests: The maximum parallel requests a single Envoy instance allows to the Kubernetes Service; defaults to 1024contour.heptio.com/max-retries: The maximum number of parallel retries a single Envoy instance allows to the Kubernetes Service; defaults to 1024. This is independent of the per-Kubernetes Ingress number of retries (contour.heptio.com/num-retries) and retry-on (contour.heptio.com/retry-on), which control whether retries are attempted and how many times a single request can retry.contour.heptio.com/upstream-protocol.{protocol}: The protocol used in the upstream. The annotation value contains a list of port names and/or numbers separated by a comma that must match with the ones defined in theServicedefinition. For now, justh2andh2care supported:contour.heptio.com/upstream-protocol.h2: "443,https". Defaults to Envoy's default behavior which ishttp1in the upstream.