Backend CRD

The Backend custom resource extends the Kubernetes API to let you manage how traffic is load balanced across pods.

Install the Backend custom resource

Before you can use the Backend custom resource, you must install its definition into your Kubernetes cluster.

1. Install the custom resource definition with kubectl apply:

   Community ingress controller

   $ kubectl apply -f https://cdn.haproxy.com/documentation/kubernetes/1.10/community/crd/backend.yaml

2. Verify that the installation worked by listing custom resources defined in your cluster:

   $ kubectl get crd

   output

   NAME                        CREATED AT
   backends.core.haproxy.org   2022-01-21T20:00:31Z
   

Use the Backend custom resource

With the Backend custom resource, you can manage how traffic is load balanced across pods. To use it:

1. Create a YAML file that declares a Backend resource and add properties to its spec.config section.

   In the example below, the balance.algorithm property changes the load balancing algorithm to least connections.

   example-backend.yaml

   apiVersion: "core.haproxy.org/v1alpha1"
   kind: Backend
   metadata:
     name: example-backend
     namespace: default
   spec:
     config:
       balance:
         algorithm: "leastconn"

2. Deploy it to your cluster using kubectl apply.

   $ kubectl apply -f example-backend.yaml

3. Decide which Kubernetes services the resource should apply to. Do one of the following:

   • To have the properties apply to all services, create a new ConfigMap with the name haproxy-kubernetes-ingress to override the one that ships with the ingress controller. Add the cr-backend key to the data section to implement the backend properties.

     example-configmap.yaml

     apiVersion: v1
     kind: ConfigMap
     metadata:
       name: haproxy-kubernetes-ingress
       namespace: haproxy-controller
     data:
       cr-backend: default/example-backend

     Update the ConfigMap in your cluster by using kubectl apply:

     $ kubectl apply -f  example-configmap.yaml

   • To have the properties apply to all services that the Ingress routes traffic to, add the cr-backend annotation to your Ingress definition . The Ingress below applies to the services example-service1 and example-service2:

     example-ingress.yaml

     apiVersion: networking.k8s.io/v1
     kind: Ingress
     metadata:
         name: example-ingress
         annotations:
            haproxy.org/cr-backend: default/example-backend
     spec:
         rules:
         - http:
             paths:
             - path: /example1
               pathType: Prefix
               backend:
                 service:
                   name: example-service1
                   port:
                     number: 80
             - path: /example2
               pathType: Prefix
               backend:
                 service:
                   name: example-service2
                   port:
                     number: 80

     Update the Ingress in your cluster by using kubectl apply:

     $ kubectl apply -f  example-ingress.yaml

   • To have the properties apply to only a specific Kubernetes service, add the cr-backend annotation to your Service definition. The Service below applies the properties only to the service named example-service1.

     example-service.yaml

     apiVersion: v1
     kind: Service
     metadata:
       labels:
         run: app
       name: example-service1
       annotations:
         haproxy.org/cr-backend: default/example-backend
     spec:
       selector:
         run: app
       ports:
       - name: http
         port: 80
         protocol: TCP
         targetPort: 8080

     Update the Service in your cluster by using kubectl apply:

     $ kubectl apply -f  example-service.yaml

Backend custom resource reference

Version: core.haproxy.org/v1alpha2

abortonclose

accept_invalid_http_response

adv_check

allbackups

balance

bind_process

check_timeout

compression

connect_timeout

cookie

default_server

dynamic_cookie_key

external_check

external_check_command

external_check_path

forwardfor

h1_case_adjust_bogus_server

hash_type

http-buffer-request

http-check

http-keep-alive

http-no-delay

http-server-close

http-use-htx

http_connection_mode

http_keep_alive_timeout

http_pretend_keepalive

http_proxy

http_request_timeout

http_reuse

httpchk_params

httpclose

log_health_checks

log_tag

mode

mysql_check_params

name

pgsql_check_params

queue_timeout

redispatch

retries

server_timeout

smtpchk_params

srvtcpka

stats_options

stick_table

tcpka

tunnel_timeout

---

Next up

Defaults CRD