Preserving the source IP address

To preserve source IP addresses, you can enable the PROXY protocol for VPC clusters. This option is available for clusters that run version 4.13 or later.

The PROXY protocol provides a convenient way to transport connection information, such as a client's address, across multiple layers of NAT or TCP proxies. For more information on the PROXY protocol, see the HAProxy specification.

By default, the Ingress controller receives connections that contain only the source address associated with the load balancer. You can enable the PROXY protocol in VPC clusters to configure the load balancer to preserve the original client address for connections that the Ingress controller receives.

Customizing Ingress routing with annotations

If you want to customize routing rules for your app, you can use route-specific HAProxy annotations in the Ingress resources that you define.

These supported annotations are in the format haproxy.router.openshift.io/<annotation> or router.openshift.io/<annotation>.IBM Cloud Kubernetes Service annotations (ingress.bluemix.net/<annotation>) and NGINX annotations (nginx.ingress.kubernetes.io/<annotation>) are not supported for the Ingress controller or the Ingress resource in Red Hat OpenShift version 4.

Enabling access logging

HTTP access logs contain information of incoming HTTP requests. Having access logs is useful when debugging complex problems, but the OpenShift router doesn't support access logging by default. For OpenShift clusters, you can configure access logging for routers, which results in having a sidecar container in the router pod that runs a syslog server and writes access logs to its stdout.

1. Edit the IngressController configuration and add the following configuration to the .spec.

   logging:
     access:
       destination:
         type: Container
       httpCaptureHeaders:
         request:
         - maxLength: 256
           name: Host
       httpLogFormat: '{"time_date":"%t","client":"%ci","host":"%[capture.req.hdr(0)]","ssl_version":"%sslv","request_method":"%HM",
                      "request_uri":"%HU","status":%ST,"upstream_addr":"%si:%sp","request_time":%Tt,"upstream_connect_time":%Tc,
                      "upstream_header_time":%Tr,"termination_state":"%ts"}'
   

   Edit command

   kubectl edit ingresscontroller -n openshift-ingress-operator default
   ingresscontroller.operator.openshift.io/default edited
   

2. Check if the router pods are running two containers.

   kubectl get pod -n openshift-ingress -w
   

   Example output

   NAME                              READY   STATUS    RESTARTS   AGE
   router-default-66945cc7c4-4xlnh   2/2     Running   0          36s
   router-default-66945cc7c4-5cxpn   2/2     Running   0          36s
   

3. Check access logs.

   kubectl logs -n openshift-ingress router-default-66945cc7c4-4xlnh -c logs
   

   Example output

   ...
   2025-01-28T12:29:07.038592+00:00 router-default-7fc484bbb8-qfm5d router-default-7fc484bbb8-qfm5d haproxy[41]:{"time_date":
   "28/Jan/2025:12:29:06.879","client":"10.5.207.79","host":"alb-autoscale-example-service-default.pvg-classic-z9g5zltmgb1ir
   -1e7743ca80a399c9cff4eaf617434c72-0000.us-south.stg.kube.appdomain.cloud","ssl_version":"TLSv1.3","request_method":
   "GET","request_uri":"/","status":200,"upstream_addr":"172.30.210.252:8080","request_time":159,"upstream_connect_time":1,
   "upstream_header_time":2,"termination_state":"--"}
   2025-01-28T12:29:09.572129+00:00 router-default-7fc484bbb8-qfm5d router-default-7fc484bbb8-qfm5d haproxy[41]: {"time_date":
   "28/Jan/2025:12:29:09.405","client":"10.5.207.79","host":"alb-autoscale-example-service-default.pvg-classic-z9g5zltmgb1ir
   -1e7743ca80a399c9cff4eaf617434c72-0000.us-south.stg.kube.appdomain.cloud","ssl_version":"TLSv1.3","request_method":"GET",
   "request_uri":"/","status":200,"upstream_addr":"172.30.210.252:8080","request_time":166,"upstream_connect_time":0,
   "upstream_header_time":3,"termination_state":"--"}
   ...
   

Fine-tuning connection handling

The clientTimeout and serverTimeout parameters are crucial configurations that dictate how long connections remain active between clients, the Ingress controller, and the backend servers. These timeouts play a significant role in optimizing request handling, particularly when dealing with long-lasting client connections, delayed responses from backend servers, and safeguarding valuable resources from being unnecessarily occupied.

If you anticipate that clients will keep connections open for a longer period of time, it is advisable to increase the clientTimeout setting to cater to these scenarios. Conversely, if your backend servers have high latency due to high traffic volumes or processing loads, adjusting the serverTimeout can provide the necessary allowance for the servers to complete their request processing before the Ingress controller terminates the connection.

You can change the above parameters in your IngressController resource:

apiVersion: operator.openshift.io/v1
kind: IngressController
 ...
spec:
  tuningOptions:
    clientTimeout: 5s
    serverTimeout: 5s

For more information about tuning options see the OpenShift documentation.