Configuring Kourier - Configuring OpenShift Serverless applications | Serving

Accessing the current Envoy bootstrap configuration
Customizing kourier-bootstrap for Kourier getaways
Enabling administrator interface access

Kourier is a lightweight Kubernetes-native Ingress for Knative Serving. Kourier acts as a gateway for Knative, routing HTTP traffic to Knative services.

Accessing the current Envoy bootstrap configuration

The Envoy proxy component in Kourier handles inbound and outbound HTTP traffic for the Knative services. By default, Kourier contains an Envoy bootstrap configuration in the kourier-bootstrap configuration map in the knative-serving-ingress namespace.

Procedure

To get the current Envoy bootstrap configuration, run the following command:

Example command

$ oc get cm kourier-bootstrap -n knative-serving-ingress -o yaml

For example, with the default configuration, the example command produces the output that contains the following excerpts:

Example output

Name:         kourier-bootstrap
Namespace:    knative-serving-ingress
Labels:       app.kubernetes.io/component=net-kourier
              app.kubernetes.io/name=knative-serving
              app.kubernetes.io/version=release-v1.10
              networking.knative.dev/ingress-provider=kourier
              serving.knative.openshift.io/ownerName=knative-serving
              serving.knative.openshift.io/ownerNamespace=knative-serving
Annotations:  manifestival: new

Example Data output

dynamic_resources:
  ads_config:
    transport_api_version: V3
    api_type: GRPC
    rate_limit_settings: {}
    grpc_services:
    - envoy_grpc: {cluster_name: xds_cluster}
  cds_config:
    resource_api_version: V3
    ads: {}
  lds_config:
    resource_api_version: V3
    ads: {}
node:
  cluster: kourier-knative
  id: 3scale-kourier-gateway
static_resources:
  listeners:
    - name: stats_listener
      address:
        socket_address:
          address: 0.0.0.0
          port_value: 9000
      filter_chains:
        - filters:
            - name: envoy.filters.network.http_connection_manager
              typed_config:
                "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
                stat_prefix: stats_server
                http_filters:
                  - name: envoy.filters.http.router
                    typed_config:
                      "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router
                route_config:
                  virtual_hosts:
                    - name: admin_interface
                      domains:
                        - "*"
                      routes:
                        - match:
                            safe_regex:
                              regex: '/(certs|stats(/prometheus)?|server_info|clusters|listeners|ready)?'
                            headers:
                              - name: ':method'
                                string_match:
                                  exact: GET
                          route:
                            cluster: service_stats
  clusters:
    - name: service_stats
      connect_timeout: 0.250s
      type: static
      load_assignment:
        cluster_name: service_stats
        endpoints:
          lb_endpoints:
            endpoint:
              address:
                pipe:
                  path: /tmp/envoy.admin
    - name: xds_cluster
      # This keepalive is recommended by envoy docs.
      # https://www.envoyproxy.io/docs/envoy/latest/api-docs/xds_protocol
      typed_extension_protocol_options:
        envoy.extensions.upstreams.http.v3.HttpProtocolOptions:
          "@type": type.googleapis.com/envoy.extensions.upstreams.http.v3.HttpProtocolOptions
          explicit_http_config:
            http2_protocol_options:
              connection_keepalive:
                interval: 30s
                timeout: 5s
      connect_timeout: 1s
      load_assignment:
        cluster_name: xds_cluster
        endpoints:
          lb_endpoints:
            endpoint:
              address:
                socket_address:
                  address: "net-kourier-controller.knative-serving-ingress.svc.cluster.local."
                  port_value: 18000
      type: STRICT_DNS
admin:
  access_log:
  - name: envoy.access_loggers.stdout
    typed_config:
      "@type": type.googleapis.com/envoy.extensions.access_loggers.stream.v3.StdoutAccessLog
  address:
    pipe:
      path: /tmp/envoy.admin
layered_runtime:
  layers:
    - name: static-layer
      static_layer:
        envoy.reloadable_features.override_request_timeout_by_gateway_timeout: false

Example BinaryData output

Events:  <none>

Customizing kourier-bootstrap for Kourier getaways

Prerequisites

You have installed the OpenShift Serverless Operator and Knative Serving.
You have cluster administrator permissions on OpenShift Container Platform, or you have cluster or dedicated administrator permissions on Red Hat OpenShift Service on AWS or OpenShift Dedicated.

Procedure

Specify a custom bootstrapping configuration map by changing the spec.ingress.kourier.bootstrap-configmap field in the KnativeServing custom resource (CR):

Example KnativeServing CR

apiVersion: operator.knative.dev/v1beta1
kind: KnativeServing
metadata:
  name: knative-serving
  namespace: knative-serving
spec:
  config:
    network:
      ingress-class: kourier.ingress.networking.knative.dev
  ingress:
    kourier:
      bootstrap-configmap: my-configmap
      enabled: true
# ...

Enabling administrator interface access

You can change the envoy bootstrap configuration to enable access to the administrator interface.

This procedure assumes sufficient knowledge of Knative, as changing envoy bootstrap configuration might result in Knative failure. Red Hat does not support custom configurations that are not tested or shipped with the product.

Prerequisites

You have installed the OpenShift Serverless Operator and Knative Serving.
You have cluster administrator permissions on OpenShift Container Platform, or you have cluster or dedicated administrator permissions on Red Hat OpenShift Service on AWS or OpenShift Dedicated.

Procedure

To enable administrator interface access, locate this configuration in your bootstrapping configuration map:
```
pipe:
  path: /tmp/envoy.admin
```
Substitute it with the following configuration:
```
socket_address: (1)
  address: 127.0.0.1
  port_value: 9901
```
1 This configuration enables access to the Envoy admin interface on the loopback address (127.0.0.1) and port 9901.

Apply the socket_address configuration in the service_stats cluster configuration and in the admin configuration:

The first is in the service_stats cluster configuration:

clusters:
  - name: service_stats
    connect_timeout: 0.250s
    type: static
    load_assignment:
      cluster_name: service_stats
      endpoints:
        lb_endpoints:
          endpoint:
            address:
              socket_address:
                address: 127.0.0.1
                port_value: 9901

The second is in the admin configuration:

admin:
  access_log:
    - name: envoy.access_loggers.stdout
      typed_config:
        "@type": type.googleapis.com/envoy.extensions.access_loggers.stream.v3.StdoutAccessLog
  address:
    socket_address:
      address: 127.0.0.1
      port_value: 9901