Understanding the Ingress Operator | Networking

OKD Ingress Operator
The Ingress configuration asset
Ingress Controller configuration parameters
- Ingress Controller TLS security profiles
- Ingress controller endpoint publishing strategy
View the default Ingress Controller
View Ingress Operator status
View Ingress Controller logs
View Ingress Controller status
Configuring the Ingress Controller
Additional resources

OKD Ingress Operator

When you create your OKD cluster, pods and services running on the cluster are each allocated their own IP addresses. The IP addresses are accessible to other pods and services running nearby but are not accessible to outside clients. The Ingress Operator implements the IngressController API and is the component responsible for enabling external access to OKD cluster services.

The Ingress Operator makes it possible for external clients to access your service by deploying and managing one or more HAProxy-based Ingress Controllers to handle routing. You can use the Ingress Operator to route traffic by specifying OKD Route and Kubernetes Ingress resources. Configurations within the Ingress Controller, such as the ability to define endpointPublishingStrategy type and internal load balancing, provide ways to publish Ingress Controller endpoints.

The Ingress configuration asset

The installation program generates an asset with an Ingress resource in the config.openshift.io API group, cluster-ingress-02-config.yml.

YAML Definition of the Ingress resource

apiVersion: config.openshift.io/v1
kind: Ingress
metadata:
  name: cluster
spec:
  domain: apps.openshiftdemos.com

The installation program stores this asset in the cluster-ingress-02-config.yml file in the manifests/ directory. This Ingress resource defines the cluster-wide configuration for Ingress. This Ingress configuration is used as follows:

The Ingress Operator uses the domain from the cluster Ingress configuration as the domain for the default Ingress Controller.
The OpenShift API Server Operator uses the domain from the cluster Ingress configuration. This domain is also used when generating a default host for a Route resource that does not specify an explicit host.

Ingress Controller configuration parameters

The ingresscontrollers.operator.openshift.io resource offers the following configuration parameters.

Parameter Description

domain

domain is a DNS name serviced by the Ingress Controller and is used to configure multiple features:

For the LoadBalancerService endpoint publishing strategy, domain is used to configure DNS records. See endpointPublishingStrategy.
When using a generated default certificate, the certificate is valid for domain and its subdomains. See defaultcertificate.
The value is published to individual Route statuses so that users know where to target external DNS records.

The domain value must be unique among all Ingress Controllers and cannot be updated.

If empty, the default value is ingress.config.openshift.io/cluster .spec.domain.

replicas

replicas is the desired number of Ingress Controller replicas. If not set, the default value is 2.

endpointPublishingStrategy

endpointPublishingStrategy is used to publish the Ingress Controller endpoints to other networks, enable load balancer integrations, and provide access to other systems.

If not set, the default value is based on infrastructure.config.openshift.io/cluster .status.platform:

AWS: LoadBalancerService (with external scope)
Azure: LoadBalancerService (with external scope)
GCP: LoadBalancerService (with external scope)
Bare metal: NodePortService
Other: HostNetwork

For most platforms, the endpointPublishingStrategy value cannot be updated. However, on GCP, you can configure the loadbalancer.providerParameters.gcp.clientAccess subfield.

defaultcertificate

The defaultcertificate value is a reference to a secret that contains the default certificate that is served by the Ingress Controller. When Routes do not specify their own certificate, defaultcertificate is used.

The secret must contain the following keys and data: * tls.crt: certificate file contents * tls.key: key file contents

If not set, a wildcard certificate is automatically generated and used. The certificate is valid for the Ingress Controller domain and subdomains, and the generated certificate’s CA is automatically integrated with the cluster’s trust store.

The in-use certificate, whether generated or user-specified, is automatically integrated with OKD built-in OAuth server.

namespaceSelector

namespaceSelector is used to filter the set of namespaces serviced by the Ingress Controller. This is useful for implementing shards.

routeSelector

routeSelector is used to filter the set of Routes serviced by the Ingress Controller. This is useful for implementing shards.

nodePlacement

nodePlacement enables explicit control over the scheduling of the Ingress Controller.

If not set, the defaults values are used.

The nodePlacement parameter includes two parts, nodeSelector and tolerations. For example:

nodePlacement:
 nodeSelector:
   matchLabels:
     kubernetes.io/os: linux
 tolerations:
 - effect: NoSchedule
   operator: Exists

tlsSecurityProfile

tlsSecurityProfile specifies settings for TLS connections for Ingress Controllers.

If not set, the default value is based on the apiservers.config.openshift.io/cluster resource.

When using the Old, Intermediate, and Modern profile types, the effective profile configuration is subject to change between releases. For example, given a specification to use the Intermediate profile deployed on release X.Y.Z, an upgrade to release X.Y.Z+1 may cause a new profile configuration to be applied to the Ingress Controller, resulting in a rollout.

The minimum TLS version for Ingress Controllers is 1.1, and the maximum TLS version is 1.2.

The HAProxy Ingress Controller image does not support TLS 1.3 and because the Modern profile requires TLS 1.3, it is not supported. The Ingress Operator converts the Modern profile to Intermediate.

The Ingress Operator also converts the TLS 1.0 of an Old or Custom profile to 1.1, and TLS 1.3 of a Custom profile to 1.2.

OKD router enables Red Hat-distributed OpenSSL default set of TLS 1.3 cipher suites, which uses TLS_AES_128_CCM_SHA256, TLS_CHACHA20_POLY1305_SHA256, TLS_AES_256_GCM_SHA384, and TLS_AES_128_GCM_SHA256. Your cluster might accept TLS 1.3 connections and cipher suites, even though TLS 1.3 is unsupported in OKD 4.6, 4.7, and 4.8.

Ciphers and the minimum TLS version of the configured security profile are reflected in the TLSProfile status.

routeAdmission

routeAdmission defines a policy for handling new route claims, such as allowing or denying claims across namespaces.

namespaceOwnership describes how hostname claims across namespaces should be handled. The default is Strict.

Strict: does not allow routes to claim the same hostname across namespaces.
InterNamespaceAllowed: allows routes to claim different paths of the same hostname across namespaces.

wildcardPolicy describes how routes with wildcard policies are handled by the Ingress Controller.

WildcardsAllowed: Indicates routes with any wildcard policy are admitted by the Ingress Controller.
WildcardsDisallowed: Indicates only routes with a wildcard policy of None are admitted by the Ingress Controller. Updating wildcardPolicy from WildcardsAllowed to WildcardsDisallowed causes admitted routes with a wildcard policy of Subdomain to stop working. These routes must be recreated to a wildcard policy of None to be readmitted by the Ingress Controller. WildcardsDisallowed is the default setting.

IngressControllerLogging

logging defines parameters for what is logged where. If this field is empty, operational logs are enabled but access logs are disabled.

access describes how client requests are logged. If this field is empty, access logging is disabled.
- destination describes a destination for log messages.
  - type is the type of destination for logs:
    
    Container specifies that logs should go to a sidecar container. The Ingress Operator configures the container, named logs, on the Ingress Controller pod and configures the Ingress Controller to write logs to the container. The expectation is that the administrator configures a custom logging solution that reads logs from this container. Using container logs means that logs may be dropped if the rate of logs exceeds the container runtime capacity or the custom logging solution capacity.
    
    Syslog specifies that logs are sent to a Syslog endpoint. The administrator must specify an endpoint that can receive Syslog messages. The expectation is that the administrator has configured a custom Syslog instance.
  - container describes parameters for the Container logging destination type. Currently there are no parameters for container logging, so this field must be empty.
  - syslog describes parameters for the Syslog logging destination type:
    
    address is the IP address of the syslog endpoint that receives log messages.
    
    port is the UDP port number of the syslog endpoint that receives log messages.
    
    facility specifies the syslog facility of log messages. If this field is empty, the facility is local1. Otherwise, it must specify a valid syslog facility: kern, user, mail, daemon, auth, syslog, lpr, news, uucp, cron, auth2, ftp, ntp, audit, alert, cron2, local0, local1, local2, local3. local4, local5, local6, or local7.
- httpLogFormat specifies the format of the log message for an HTTP request. If this field is empty, log messages use the implementation’s default HTTP log format. For HAProxy’s default HTTP log format, see the HAProxy documentation.

httpHeaders

httpHeaders defines the policy for HTTP headers.

By setting the forwardedHeaderPolicy for the IngressControllerHTTPHeaders, you specify when and how the Ingress controller sets the Forwarded, X-Forwarded-For, X-Forwarded-Host, X-Forwarded-Port, X-Forwarded-Proto, and X-Forwarded-Proto-Version HTTP headers.

By default, the policy is set to Append.

Append specifies that the Ingress Controller appends the headers, preserving any existing headers.
Replace specifies that the Ingress Controller sets the headers, removing any existing headers.
IfNone specifies that the Ingress Controller sets the headers if they are not already set.
Never specifies that the Ingress Controller never sets the headers, preserving any existing headers.

By setting headerNameCaseAdjustments, you can specify case adjustments that can be applied to HTTP header names. Each adjustment is specified as an HTTP header name with the desired capitalization. For example, specifying X-Forwarded-For indicates that the x-forwarded-for HTTP header should be adjusted to have the specified capitalization.

These adjustments are only applied to cleartext, edge-terminated, and re-encrypt routes, and only when using HTTP/1.

For request headers, these adjustments are applied only for routes that have the haproxy.router.openshift.io/h1-adjust-case=true annotation. For response headers, these adjustments are applied to all HTTP responses. If this field is empty, no request headers are adjusted.

httpCompression

httpCompression defines the policy for HTTP traffic compression.

mimeTypes defines a list of MIME types to which compression should be applied. For example, text/css; charset=utf-8, text/html, text/*, image/svg+xml, application/octet-stream, X-custom/customsub, using the format pattern, type/subtype; [;attribute=value]. The types are: application, image, message, multipart, text, video, or a custom type prefaced by X-; e.g. To see the full notation for MIME types and subtypes, see RFC1341

httpErrorCodePages

httpErrorCodePages specifies custom HTTP error code response pages. By default, an IngressController uses error pages built into the IngressController image.

httpCaptureCookies

httpCaptureCookies specifies HTTP cookies that you want to capture in access logs. If the httpCaptureCookies field is empty, the access logs do not capture the cookies.

For any cookie that you want to capture, the following parameters must be in your IngressController configuration:

name specifies the name of the cookie.
maxLength specifies tha maximum length of the cookie.
matchType specifies if the field name of the cookie exactly matches the capture cookie setting or is a prefix of the capture cookie setting. The matchType field uses the Exact and Prefix parameters.

For example:

  httpCaptureCookies:
  - matchType: Exact
    maxLength: 128
    name: MYCOOKIE

httpCaptureHeaders

httpCaptureHeaders specifies the HTTP headers that you want to capture in the access logs. If the httpCaptureHeaders field is empty, the access logs do not capture the headers.

httpCaptureHeaders contains two lists of headers to capture in the access logs. The two lists of header fields are request and response. In both lists, the name field must specify the header name and the maxlength field must specify the maximum length of the header. For example:

  httpCaptureHeaders:
    request:
    - maxLength: 256
      name: Connection
    - maxLength: 128
      name: User-Agent
    response:
    - maxLength: 256
      name: Content-Type
    - maxLength: 256
      name: Content-Length

tuningOptions

tuningOptions specifies options for tuning the performance of Ingress Controller pods.

headerBufferBytes specifies how much memory is reserved, in bytes, for Ingress Controller connection sessions. This value must be at least 16384 if HTTP/2 is enabled for the Ingress Controller. If not set, the default value is 32768 bytes. Setting this field not recommended because headerBufferBytes values that are too small can break the Ingress Controller, and headerBufferBytes values that are too large could cause the Ingress Controller to use significantly more memory than necessary.
headerBufferMaxRewriteBytes specifies how much memory should be reserved, in bytes, from headerBufferBytes for HTTP header rewriting and appending for Ingress Controller connection sessions. The minimum value for headerBufferMaxRewriteBytes is 4096. headerBufferBytes must be greater than headerBufferMaxRewriteBytes for incoming HTTP requests. If not set, the default value is 8192 bytes. Setting this field not recommended because headerBufferMaxRewriteBytes values that are too small can break the Ingress Controller and headerBufferMaxRewriteBytes values that are too large could cause the Ingress Controller to use significantly more memory than necessary.
threadCount specifies the number of threads to create per HAProxy process. Creating more threads allows each Ingress Controller pod to handle more connections, at the cost of more system resources being used. HAProxy supports up to 64 threads. If this field is empty, the Ingress Controller uses the default value of 4 threads. The default value can change in future releases. Setting this field is not recommended because increasing the number of HAProxy threads allows Ingress Controller pods to use more CPU time under load, and prevent other pods from receiving the CPU resources they need to perform. Reducing the number of threads can cause the Ingress Controller to perform poorly.

All parameters are optional.

Ingress Controller TLS security profiles

TLS security profiles provide a way for servers to regulate which ciphers a connecting client can use when connecting to the server.

Understanding TLS security profiles

You can use a TLS (Transport Layer Security) security profile to define which TLS ciphers are required by various OKD components. The OKD TLS security profiles are based on Mozilla recommended configurations.

You can specify one of the following TLS security profiles for each component:

Profile Description

Old

This profile is intended for use with legacy clients or libraries. The profile is based on the Old backward compatibility recommended configuration.

The Old profile requires a minimum TLS version of 1.0.

For the Ingress Controller, the minimum TLS version is converted from 1.0 to 1.1.

Intermediate

This profile is the recommended configuration for the majority of clients. It is the default TLS security profile for the Ingress Controller, kubelet, and control plane. The profile is based on the Intermediate compatibility recommended configuration.

The Intermediate profile requires a minimum TLS version of 1.2.

Modern

This profile is intended for use with modern clients that have no need for backwards compatibility. This profile is based on the Modern compatibility recommended configuration.

The Modern profile requires a minimum TLS version of 1.3.

In OKD 4.6, 4.7, and 4.8, the Modern profile is unsupported. If selected, the Intermediate profile is enabled.

The Modern profile is currently not supported.

Custom

This profile allows you to define the TLS version and ciphers to use.

Use caution when using a Custom profile, because invalid configurations can cause problems.

OKD router enables Red Hat-distributed OpenSSL default set of TLS 1.3 cipher suites. Your cluster might accept TLS 1.3 connections and cipher suites, even though TLS 1.3 is unsupported in OKD 4.6, 4.7, and 4.8.

When using one of the predefined profile types, the effective profile configuration is subject to change between releases. For example, given a specification to use the Intermediate profile deployed on release X.Y.Z, an upgrade to release X.Y.Z+1 might cause a new profile configuration to be applied, resulting in a rollout.

Configuring the TLS security profile for the Ingress Controller

To configure a TLS security profile for an Ingress Controller, edit the IngressController custom resource (CR) to specify a predefined or custom TLS security profile. If a TLS security profile is not configured, the default value is based on the TLS security profile set for the API server.

Sample IngressController CR that configures the Old TLS security profile

apiVersion: operator.openshift.io/v1
kind: IngressController
 ...
spec:
  tlsSecurityProfile:
    old: {}
    type: Old
 ...

The TLS security profile defines the minimum TLS version and the TLS ciphers for TLS connections for Ingress Controllers.

You can see the ciphers and the minimum TLS version of the configured TLS security profile in the IngressController custom resource (CR) under Status.Tls Profile and the configured TLS security profile under Spec.Tls Security Profile. For the Custom TLS security profile, the specific ciphers and minimum TLS version are listed under both parameters.

The Ingress Operator also converts the TLS 1.0 of an Old or Custom profile to 1.1, and TLS 1.3 of a Custom profile to 1.2.

Prerequisites

You have access to the cluster as a user with the cluster-admin role.

Procedure

Edit the IngressController CR in the openshift-ingress-operator project to configure the TLS security profile:
```
$ oc edit IngressController default -n openshift-ingress-operator
```

Add the spec.tlsSecurityProfile field:

Sample IngressController CR for a Custom profile

apiVersion: operator.openshift.io/v1
kind: IngressController
 ...
spec:
  tlsSecurityProfile:
    type: Custom (1)
    custom: (2)
      ciphers: (3)
      - ECDHE-ECDSA-CHACHA20-POLY1305
      - ECDHE-RSA-CHACHA20-POLY1305
      - ECDHE-RSA-AES128-GCM-SHA256
      - ECDHE-ECDSA-AES128-GCM-SHA256
      minTLSVersion: VersionTLS11
 ...

1	Specify the TLS security profile type (`Old`, `Intermediate`, or `Custom`). The default is `Intermediate`.
2	Specify the appropriate field for the selected type: `old: {}` `intermediate: {}` `custom:`
3	For the `custom` type, specify a list of TLS ciphers and minimum accepted TLS version.

Save the file to apply the changes.

Verification

Verify that the profile is set in the IngressController CR:

$ oc describe IngressController default -n openshift-ingress-operator

Example output

Name:         default
Namespace:    openshift-ingress-operator
Labels:       <none>
Annotations:  <none>
API Version:  operator.openshift.io/v1
Kind:         IngressController
 ...
Spec:
 ...
  Tls Security Profile:
    Custom:
      Ciphers:
        ECDHE-ECDSA-CHACHA20-POLY1305
        ECDHE-RSA-CHACHA20-POLY1305
        ECDHE-RSA-AES128-GCM-SHA256
        ECDHE-ECDSA-AES128-GCM-SHA256
      Min TLS Version:  VersionTLS11
    Type:               Custom
 ...

Ingress controller endpoint publishing strategy

NodePortService endpoint publishing strategy

The NodePortService endpoint publishing strategy publishes the Ingress Controller using a Kubernetes NodePort service.

In this configuration, the Ingress Controller deployment uses container networking. A NodePortService is created to publish the deployment. The specific node ports are dynamically allocated by OKD; however, to support static port allocations, your changes to the node port field of the managed NodePortService are preserved.

Figure 1. Diagram of NodePortService

The preceding graphic shows the following concepts pertaining to OKD Ingress NodePort endpoint publishing strategy:

All the available nodes in the cluster have their own, externally accessible IP addresses. The service running in the cluster is bound to the unique NodePort for all the nodes.
When the client connects to a node that is down, for example, by connecting the 10.0.128.4 IP address in the graphic, the node port directly connects the client to an available node that is running the service. In this scenario, no load balancing is required. As the image shows, the 10.0.128.4 address is down and another IP address must be used instead.

The Ingress Operator ignores any updates to .spec.ports[].nodePort fields of the service.

By default, ports are allocated automatically and you can access the port allocations for integrations. However, sometimes static port allocations are necessary to integrate with existing infrastructure which may not be easily reconfigured in response to dynamic ports. To achieve integrations with static node ports, you can update the managed service resource directly.

For more information, see the Kubernetes Services documentation on NodePort.

HostNetwork endpoint publishing strategy

The HostNetwork endpoint publishing strategy publishes the Ingress Controller on node ports where the Ingress Controller is deployed.

An Ingress controller with the HostNetwork endpoint publishing strategy can have only one pod replica per node. If you want n replicas, you must use at least n nodes where those replicas can be scheduled. Because each pod replica requests ports 80 and 443 on the node host where it is scheduled, a replica cannot be scheduled to a node if another pod on the same node is using those ports.

View the default Ingress Controller

The Ingress Operator is a core feature of OKD and is enabled out of the box.

Every new OKD installation has an ingresscontroller named default. It can be supplemented with additional Ingress Controllers. If the default ingresscontroller is deleted, the Ingress Operator will automatically recreate it within a minute.

Procedure

View the default Ingress Controller:

$ oc describe --namespace=openshift-ingress-operator ingresscontroller/default

View Ingress Operator status

You can view and inspect the status of your Ingress Operator.

Procedure

View your Ingress Operator status:
```
$ oc describe clusteroperators/ingress
```

View Ingress Controller logs

You can view your Ingress Controller logs.

Procedure

View your Ingress Controller logs:

$ oc logs --namespace=openshift-ingress-operator deployments/ingress-operator

View Ingress Controller status

Your can view the status of a particular Ingress Controller.

Procedure

View the status of an Ingress Controller:

$ oc describe --namespace=openshift-ingress-operator ingresscontroller/<name>

Configuring the Ingress Controller

Setting a custom default certificate

As an administrator, you can configure an Ingress Controller to use a custom certificate by creating a Secret resource and editing the IngressController custom resource (CR).

Prerequisites

You must have a certificate/key pair in PEM-encoded files, where the certificate is signed by a trusted certificate authority or by a private trusted certificate authority that you configured in a custom PKI.
Your certificate meets the following requirements:
- The certificate is valid for the ingress domain.
- The certificate uses the subjectAltName extension to specify a wildcard domain, such as *.apps.ocp4.example.com.

You must have an IngressController CR. You may use the default one:

$ oc --namespace openshift-ingress-operator get ingresscontrollers

Example output

NAME      AGE
default   10m

If you have intermediate certificates, they must be included in the tls.crt file of the secret containing a custom default certificate. Order matters when specifying a certificate; list your intermediate certificate(s) after any server certificate(s).

Procedure

The following assumes that the custom certificate and key pair are in the tls.crt and tls.key files in the current working directory. Substitute the actual path names for tls.crt and tls.key. You also may substitute another name for custom-certs-default when creating the Secret resource and referencing it in the IngressController CR.

This action will cause the Ingress Controller to be redeployed, using a rolling deployment strategy.

Create a Secret resource containing the custom certificate in the openshift-ingress namespace using the tls.crt and tls.key files.
```
$ oc --namespace openshift-ingress create secret tls custom-certs-default --cert=tls.crt --key=tls.key
```

Update the IngressController CR to reference the new certificate secret:

$ oc patch --type=merge --namespace openshift-ingress-operator ingresscontrollers/default \
  --patch '{"spec":{"defaultcertificate":{"name":"custom-certs-default"}}}'

Verify the update was effective:

$ echo Q |\
  openssl s_client -connect console-openshift-console.apps.<domain>:443 -showcerts 2>/dev/null |\
  openssl x509 -noout -subject -issuer -enddate

where:

<domain>: Specifies the base domain name for your cluster.

Example output

subject=C = US, ST = NC, L = Raleigh, O = RH, OU = OCP4, CN = *.apps.example.com
issuer=C = US, ST = NC, L = Raleigh, O = RH, OU = OCP4, CN = example.com
notAfter=May 10 08:32:45 2022 GM

You can alternatively apply the following YAML to set a custom default certificate:

apiVersion: operator.openshift.io/v1
kind: IngressController
metadata:
  name: default
  namespace: openshift-ingress-operator
spec:
  defaultcertificate:
    name: custom-certs-default

The certificate secret name should match the value used to update the CR.

Once the IngressController CR has been modified, the Ingress Operator updates the Ingress Controller’s deployment to use the custom certificate.

Removing a custom default certificate

As an administrator, you can remove a custom certificate that you configured an Ingress Controller to use.

Prerequisites

You have access to the cluster as a user with the cluster-admin role.
You have installed the OpenShift CLI (oc).
You previously configured a custom default certificate for the Ingress Controller.

Procedure

To remove the custom certificate and restore the certificate that ships with OKD, enter the following command:
```
$ oc patch -n openshift-ingress-operator ingresscontrollers/default \
  --type json -p $'- op: remove\n  path: /spec/defaultcertificate'
```
There can be a delay while the cluster reconciles the new certificate configuration.

Verification

To confirm that the original cluster certificate is restored, enter the following command:

$ echo Q | \
  openssl s_client -connect console-openshift-console.apps.<domain>:443 -showcerts 2>/dev/null | \
  openssl x509 -noout -subject -issuer -enddate

where:

<domain>: Specifies the base domain name for your cluster.

Example output

subject=CN = *.apps.<domain>
issuer=CN = ingress-operator@1620633373
notAfter=May 10 10:44:36 2023 GMT

Scaling an Ingress Controller

Manually scale an Ingress Controller to meeting routing performance or availability requirements such as the requirement to increase throughput. oc commands are used to scale the IngressController resource. The following procedure provides an example for scaling up the default IngressController.

Scaling is not an immediate action, as it takes time to create the desired number of replicas.

Procedure

View the current number of available replicas for the default IngressController:

$ oc get -n openshift-ingress-operator ingresscontrollers/default -o jsonpath='{$.status.availableReplicas}'

Example output

Scale the default IngressController to the desired number of replicas using the oc patch command. The following example scales the default IngressController to 3 replicas:
```
$ oc patch -n openshift-ingress-operator ingresscontroller/default --patch '{"spec":{"replicas": 3}}' --type=merge
```
Example output
```
ingresscontroller.operator.openshift.io/default patched
```

Verify that the default IngressController scaled to the number of replicas that you specified:

$ oc get -n openshift-ingress-operator ingresscontrollers/default -o jsonpath='{$.status.availableReplicas}'

Example output

You can alternatively apply the following YAML to scale an Ingress Controller to three replicas:

apiVersion: operator.openshift.io/v1
kind: IngressController
metadata:
  name: default
  namespace: openshift-ingress-operator
spec:
  replicas: 3               (1)

1	If you need a different amount of replicas, change the `replicas` value.

Configuring Ingress access logging

You can configure the Ingress Controller to enable access logs. If you have clusters that do not receive much traffic, then you can log to a sidecar. If you have high traffic clusters, to avoid exceeding the capacity of the logging stack or to integrate with a logging infrastructure outside of OKD, you can forward logs to a custom syslog endpoint. You can also specify the format for access logs.

Container logging is useful to enable access logs on low-traffic clusters when there is no existing Syslog logging infrastructure, or for short-term use while diagnosing problems with the Ingress Controller.

Syslog is needed for high-traffic clusters where access logs could exceed the OpenShift Logging stack’s capacity, or for environments where any logging solution needs to integrate with an existing Syslog logging infrastructure. The Syslog use-cases can overlap.

Prerequisites

Procedure

Configure Ingress access logging to a sidecar.

To configure Ingress access logging, you must specify a destination using spec.logging.access.destination. To specify logging to a sidecar container, you must specify Container spec.logging.access.destination.type. The following example is an Ingress Controller definition that logs to a Container destination:
```
apiVersion: operator.openshift.io/v1
kind: IngressController
metadata:
  name: default
  namespace: openshift-ingress-operator
spec:
  replicas: 2
  logging:
    access:
      destination:
        type: Container
```

When you configure the Ingress Controller to log to a sidecar, the operator creates a container named logs inside the Ingress Controller Pod:

$ oc -n openshift-ingress logs deployment.apps/router-default -c logs

Example output

2020-05-11T19:11:50.135710+00:00 router-default-57dfc6cd95-bpmk6 router-default-57dfc6cd95-bpmk6 haproxy[108]: 174.19.21.82:39654 [11/May/2020:19:11:50.133] public be_http:hello-openshift:hello-openshift/pod:hello-openshift:hello-openshift:10.128.2.12:8080 0/0/1/0/1 200 142 - - --NI 1/1/0/0/0 0/0 "GET / HTTP/1.1"

Configure Ingress access logging to a Syslog endpoint.

To configure Ingress access logging, you must specify a destination using spec.logging.access.destination. To specify logging to a Syslog endpoint destination, you must specify Syslog for spec.logging.access.destination.type. If the destination type is Syslog, you must also specify a destination endpoint using spec.logging.access.destination.syslog.endpoint and you can specify a facility using spec.logging.access.destination.syslog.facility. The following example is an Ingress Controller definition that logs to a Syslog destination:
```
apiVersion: operator.openshift.io/v1
kind: IngressController
metadata:
  name: default
  namespace: openshift-ingress-operator
spec:
  replicas: 2
  logging:
    access:
      destination:
        type: Syslog
        syslog:
          address: 1.2.3.4
          port: 10514
```
The syslog destination port must be UDP.

Configure Ingress access logging with a specific log format.

You can specify spec.logging.access.httpLogFormat to customize the log format. The following example is an Ingress Controller definition that logs to a syslog endpoint with IP address 1.2.3.4 and port 10514:

apiVersion: operator.openshift.io/v1
kind: IngressController
metadata:
  name: default
  namespace: openshift-ingress-operator
spec:
  replicas: 2
  logging:
    access:
      destination:
        type: Syslog
        syslog:
          address: 1.2.3.4
          port: 10514
      httpLogFormat: '%ci:%cp [%t] %ft %b/%s %B %bq %HM %HU %HV'

Disable Ingress access logging.

To disable Ingress access logging, leave spec.logging or spec.logging.access empty:

apiVersion: operator.openshift.io/v1
kind: IngressController
metadata:
  name: default
  namespace: openshift-ingress-operator
spec:
  replicas: 2
  logging:
    access: null

Setting Ingress Controller thread count

A cluster administrator can set the thread count to increase the amount of incoming connections a cluster can handle. You can patch an existing Ingress Controller to increase the amount of threads.

Prerequisites

The following assumes that you already created an Ingress Controller.

Procedure

Update the Ingress Controller to increase the number of threads:

$ oc -n openshift-ingress-operator patch ingresscontroller/default --type=merge -p '{"spec":{"tuningOptions": {"threadCount": 8}}}'

If you have a node that is capable of running large amounts of resources, you can configure spec.nodePlacement.nodeSelector with labels that match the capacity of the intended node, and configure spec.tuningOptions.threadCount to an appropriately high value.

Ingress Controller sharding

As the primary mechanism for traffic to enter the cluster, the demands on the Ingress Controller, or router, can be significant. As a cluster administrator, you can shard the routes to:

Balance Ingress Controllers, or routers, with several routes to speed up responses to changes.
Allocate certain routes to have different reliability guarantees than other routes.
Allow certain Ingress Controllers to have different policies defined.
Allow only specific routes to use additional features.
Expose different routes on different addresses so that internal and external users can see different routes, for example.

Ingress Controller can use either route labels or namespace labels as a sharding method.

Configuring Ingress Controller sharding by using route labels

Ingress Controller sharding by using route labels means that the Ingress Controller serves any route in any namespace that is selected by the route selector.

Ingress Controller sharding is useful when balancing incoming traffic load among a set of Ingress Controllers and when isolating traffic to a specific Ingress Controller. For example, company A goes to one Ingress Controller and company B to another.

Procedure

Edit the router-internal.yaml file:

# cat router-internal.yaml
apiVersion: v1
items:
- apiVersion: operator.openshift.io/v1
  kind: IngressController
  metadata:
    name: sharded
    namespace: openshift-ingress-operator
  spec:
    domain: <apps-sharded.basedomain.example.net>
    nodePlacement:
      nodeSelector:
        matchLabels:
          node-role.kubernetes.io/worker: ""
    routeSelector:
      matchLabels:
        type: sharded
  status: {}
kind: List
metadata:
  resourceVersion: ""
  selfLink: ""

Apply the Ingress Controller router-internal.yaml file:
```
# oc apply -f router-internal.yaml
```
The Ingress Controller selects routes in any namespace that have the label type: sharded.

Configuring Ingress Controller sharding by using namespace labels

Ingress Controller sharding by using namespace labels means that the Ingress Controller serves any route in any namespace that is selected by the namespace selector.

If you deploy the Keepalived Ingress VIP, do not deploy a non-default Ingress Controller with value HostNetwork for the endpointPublishingStrategy parameter. Doing so might cause issues. Use value NodePort instead of HostNetwork for endpointPublishingStrategy.

Procedure

Edit the router-internal.yaml file:

# cat router-internal.yaml

Example output

apiVersion: v1
items:
- apiVersion: operator.openshift.io/v1
  kind: IngressController
  metadata:
    name: sharded
    namespace: openshift-ingress-operator
  spec:
    domain: <apps-sharded.basedomain.example.net>
    nodePlacement:
      nodeSelector:
        matchLabels:
          node-role.kubernetes.io/worker: ""
    namespaceSelector:
      matchLabels:
        type: sharded
  status: {}
kind: List
metadata:
  resourceVersion: ""
  selfLink: ""

Apply the Ingress Controller router-internal.yaml file:
```
# oc apply -f router-internal.yaml
```
The Ingress Controller selects routes in any namespace that is selected by the namespace selector that have the label type: sharded.

Configuring an Ingress Controller to use an internal load balancer

When creating an Ingress Controller on cloud platforms, the Ingress Controller is published by a public cloud load balancer by default. As an administrator, you can create an Ingress Controller that uses an internal cloud load balancer.

If your cloud provider is Microsoft Azure, you must have at least one public load balancer that points to your nodes. If you do not, all of your nodes will lose egress connectivity to the internet.

If you want to change the scope for an IngressController object, you must delete and then recreate that IngressController object. You cannot change the .spec.endpointPublishingStrategy.loadBalancer.scope parameter after the custom resource (CR) is created.

Figure 2. Diagram of LoadBalancer

The preceding graphic shows the following concepts pertaining to OKD Ingress LoadBalancerService endpoint publishing strategy:

You can load load balance externally, using the cloud provider load balancer, or internally, using the OpenShift Ingress Controller Load Balancer.
You can use the single IP address of the load balancer and more familiar ports, such as 8080 and 4200 as shown on the cluster depicted in the graphic.
Traffic from the external load balancer is directed at the pods, and managed by the load balancer, as depicted in the instance of a down node. See the Kubernetes Services documentation for implementation details.

Prerequisites

Install the OpenShift CLI (oc).
Log in as a user with cluster-admin privileges.

Procedure

Create an IngressController custom resource (CR) in a file named <name>-ingress-controller.yaml, such as in the following example:

apiVersion: operator.openshift.io/v1
kind: IngressController
metadata:
  namespace: openshift-ingress-operator
  name: <name> (1)
spec:
  domain: <domain> (2)
  endpointPublishingStrategy:
    type: LoadBalancerService
    loadBalancer:
      scope: Internal (3)

1	Replace `<name>` with a name for the `IngressController` object.
2	Specify the `domain` for the application published by the controller.
3	Specify a value of `Internal` to use an internal load balancer.

Create the Ingress Controller defined in the previous step by running the following command:
```
$ oc create -f <name>-ingress-controller.yaml (1)
```
1 Replace <name> with the name of the IngressController object.
Optional: Confirm that the Ingress Controller was created by running the following command:
```
$ oc --all-namespaces=true get ingresscontrollers
```

Configuring global access for an Ingress Controller on GCP

An Ingress Controller created on GCP with an internal load balancer generates an internal IP address for the service. A cluster administrator can specify the global access option, which enables clients in any region within the same VPC network and compute region as the load balancer, to reach the workloads running on your cluster.

For more information, see the GCP documentation for global access.

Prerequisites

You deployed an OKD cluster on GCP infrastructure.
You configured an Ingress Controller to use an internal load balancer.
You installed the OpenShift CLI (oc).

Procedure

Configure the Ingress Controller resource to allow global access.

You can also create an Ingress Controller and specify the global access option.

Configure the Ingress Controller resource:

$ oc -n openshift-ingress-operator edit ingresscontroller/default

Edit the YAML file:

Sample clientAccess configuration to Global

  spec:
    endpointPublishingStrategy:
      loadBalancer:
        providerParameters:
          gcp:
            clientAccess: Global (1)
          type: GCP
        scope: Internal
      type: LoadBalancerService

1	Set `gcp.clientAccess` to `Global`.

Save the file to apply the changes.

Run the following command to verify that the service allows global access:
```
$ oc -n openshift-ingress edit svc/router-default -o yaml
```
The output shows that global access is enabled for GCP with the annotation, networking.gke.io/internal-load-balancer-allow-global-access.

Configuring the default Ingress Controller for your cluster to be internal

You can configure the default Ingress Controller for your cluster to be internal by deleting and recreating it.

If your cloud provider is Microsoft Azure, you must have at least one public load balancer that points to your nodes. If you do not, all of your nodes will lose egress connectivity to the internet.

Prerequisites

Install the OpenShift CLI (oc).
Log in as a user with cluster-admin privileges.

Procedure

Configure the default Ingress Controller for your cluster to be internal by deleting and recreating it.

$ oc replace --force --wait --filename - <<EOF
apiVersion: operator.openshift.io/v1
kind: IngressController
metadata:
  namespace: openshift-ingress-operator
  name: default
spec:
  endpointPublishingStrategy:
    type: LoadBalancerService
    loadBalancer:
      scope: Internal
EOF

Configuring the route admission policy

Administrators and application developers can run applications in multiple namespaces with the same domain name. This is for organizations where multiple teams develop microservices that are exposed on the same hostname.

Allowing claims across namespaces should only be enabled for clusters with trust between namespaces, otherwise a malicious user could take over a hostname. For this reason, the default admission policy disallows hostname claims across namespaces.

Prerequisites

Cluster administrator privileges.

Procedure

Edit the .spec.routeAdmission field of the ingresscontroller resource variable using the following command:

$ oc -n openshift-ingress-operator patch ingresscontroller/default --patch '{"spec":{"routeAdmission":{"namespaceOwnership":"InterNamespaceAllowed"}}}' --type=merge

Sample Ingress Controller configuration

spec:
  routeAdmission:
    namespaceOwnership: InterNamespaceAllowed
...

You can alternatively apply the following YAML to configure the route admission policy:

apiVersion: operator.openshift.io/v1
kind: IngressController
metadata:
  name: default
  namespace: openshift-ingress-operator
spec:
  routeAdmission:
    namespaceOwnership: InterNamespaceAllowed

Using wildcard routes

The HAProxy Ingress Controller has support for wildcard routes. The Ingress Operator uses wildcardPolicy to configure the ROUTER_ALLOW_WILDCARD_ROUTES environment variable of the Ingress Controller.

The default behavior of the Ingress Controller is to admit routes with a wildcard policy of None, which is backwards compatible with existing IngressController resources.

Procedure

Configure the wildcard policy.
1. Use the following command to edit the IngressController resource:
  $ oc edit IngressController
2. Under spec, set the wildcardPolicy field to WildcardsDisallowed or WildcardsAllowed:
  spec: routeAdmission: wildcardPolicy: WildcardsDisallowed # or WildcardsAllowed

Using X-Forwarded headers

You configure the HAProxy Ingress Controller to specify a policy for how to handle HTTP headers including Forwarded and X-Forwarded-For. The Ingress Operator uses the HTTPHeaders field to configure the ROUTER_SET_FORWARDED_HEADERS environment variable of the Ingress Controller.

Procedure

Configure the HTTPHeaders field for the Ingress Controller.

Use the following command to edit the IngressController resource:
```
$ oc edit IngressController
```

Under spec, set the HTTPHeaders policy field to Append, Replace, IfNone, or Never:

apiVersion: operator.openshift.io/v1
kind: IngressController
metadata:
  name: default
  namespace: openshift-ingress-operator
spec:
  httpHeaders:
    forwardedHeaderPolicy: Append

Example use cases

As a cluster administrator, you can:

Configure an external proxy that injects the X-Forwarded-For header into each request before forwarding it to an Ingress Controller.

To configure the Ingress Controller to pass the header through unmodified, you specify the never policy. The Ingress Controller then never sets the headers, and applications receive only the headers that the external proxy provides.
Configure the Ingress Controller to pass the X-Forwarded-For header that your external proxy sets on external cluster requests through unmodified.

To configure the Ingress Controller to set the X-Forwarded-For header on internal cluster requests, which do not go through the external proxy, specify the if-none policy. If an HTTP request already has the header set through the external proxy, then the Ingress Controller preserves it. If the header is absent because the request did not come through the proxy, then the Ingress Controller adds the header.

As an application developer, you can:

Configure an application-specific external proxy that injects the X-Forwarded-For header.

To configure an Ingress Controller to pass the header through unmodified for an application’s Route, without affecting the policy for other Routes, add an annotation haproxy.router.openshift.io/set-forwarded-headers: if-none or haproxy.router.openshift.io/set-forwarded-headers: never on the Route for the application.

You can set the haproxy.router.openshift.io/set-forwarded-headers annotation on a per route basis, independent from the globally set value for the Ingress Controller.

Enabling HTTP/2 Ingress connectivity

You can enable transparent end-to-end HTTP/2 connectivity in HAProxy. It allows application owners to make use of HTTP/2 protocol capabilities, including single connection, header compression, binary streams, and more.

You can enable HTTP/2 connectivity for an individual Ingress Controller or for the entire cluster.

To enable the use of HTTP/2 for the connection from the client to HAProxy, a route must specify a custom certificate. A route that uses the default certificate cannot use HTTP/2. This restriction is necessary to avoid problems from connection coalescing, where the client re-uses a connection for different routes that use the same certificate.

The connection from HAProxy to the application pod can use HTTP/2 only for re-encrypt routes and not for edge-terminated or insecure routes. This restriction is because HAProxy uses Application-Level Protocol Negotiation (ALPN), which is a TLS extension, to negotiate the use of HTTP/2 with the back-end. The implication is that end-to-end HTTP/2 is possible with passthrough and re-encrypt and not with insecure or edge-terminated routes.

Using WebSockets with a re-encrypt route and with HTTP/2 enabled on an Ingress Controller requires WebSocket support over HTTP/2. WebSockets over HTTP/2 is a feature of HAProxy 2.4, which is unsupported in OKD at this time.

For non-passthrough routes, the Ingress Controller negotiates its connection to the application independently of the connection from the client. This means a client may connect to the Ingress Controller and negotiate HTTP/1.1, and the Ingress Controller may then connect to the application, negotiate HTTP/2, and forward the request from the client HTTP/1.1 connection using the HTTP/2 connection to the application. This poses a problem if the client subsequently tries to upgrade its connection from HTTP/1.1 to the WebSocket protocol, because the Ingress Controller cannot forward WebSocket to HTTP/2 and cannot upgrade its HTTP/2 connection to WebSocket. Consequently, if you have an application that is intended to accept WebSocket connections, it must not allow negotiating the HTTP/2 protocol or else clients will fail to upgrade to the WebSocket protocol.

Procedure

Enable HTTP/2 on a single Ingress Controller.

To enable HTTP/2 on an Ingress Controller, enter the oc annotate command:
```
$ oc -n openshift-ingress-operator annotate ingresscontrollers/<ingresscontroller_name> ingress.operator.openshift.io/default-enable-http2=true
```
Replace <ingresscontroller_name> with the name of the Ingress Controller to annotate.

Enable HTTP/2 on the entire cluster.

To enable HTTP/2 for the entire cluster, enter the oc annotate command:

$ oc annotate ingresses.config/cluster ingress.operator.openshift.io/default-enable-http2=true

You can alternatively apply the following YAML to add the annotation:

apiVersion: config.openshift.io/v1
kind: Ingress
metadata:
  name: cluster
  annotations:
    ingress.operator.openshift.io/default-enable-http2: "true"

Configuring the PROXY protocol for an Ingress Controller

A cluster administrator can configure the PROXY protocol when an Ingress Controller uses either the HostNetwork or NodePortService endpoint publishing strategy types. The PROXY protocol enables the load balancer to preserve the original client addresses for connections that the Ingress Controller receives. The original client addresses are useful for logging, filtering, and injecting HTTP headers. In the default configuration, the connections that the Ingress Controller receives only contain the source address that is associated with the load balancer.

This feature is not supported in cloud deployments. This restriction is because when OKD runs in a cloud platform, and an IngressController specifies that a service load balancer should be used, the Ingress Operator configures the load balancer service and enables the PROXY protocol based on the platform requirement for preserving source addresses.

You must configure both OKD and the external load balancer to either use the PROXY protocol or to use TCP.

The PROXY protocol is unsupported for the default Ingress Controller with installer-provisioned clusters on non-cloud platforms that use a Keepalived Ingress VIP.

Prerequisites

You created an Ingress Controller.

Procedure

Edit the Ingress Controller resource:

$ oc -n openshift-ingress-operator edit ingresscontroller/default

Set the PROXY configuration:
- If your Ingress Controller uses the hostNetwork endpoint publishing strategy type, set the spec.endpointPublishingStrategy.hostNetwork.protocol subfield to PROXY:
  Sample hostNetwork configuration to PROXY
  spec: endpointPublishingStrategy: hostNetwork: protocol: PROXY type: HostNetwork
- If your Ingress Controller uses the NodePortService endpoint publishing strategy type, set the spec.endpointPublishingStrategy.nodePort.protocol subfield to PROXY:
  Sample nodePort configuration to PROXY
  spec: endpointPublishingStrategy: nodePort: protocol: PROXY type: NodePortService

Specifying an alternative cluster domain using the appsDomain option

As a cluster administrator, you can specify an alternative to the default cluster domain for user-created routes by configuring the appsDomain field. The appsDomain field is an optional domain for OKD to use instead of the default, which is specified in the domain field. If you specify an alternative domain, it overrides the default cluster domain for the purpose of determining the default host for a new route.

For example, you can use the DNS domain for your company as the default domain for routes and ingresses for applications running on your cluster.

Prerequisites

You deployed an OKD cluster.
You installed the oc command line interface.

Procedure

Configure the appsDomain field by specifying an alternative default domain for user-created routes.

Edit the ingress cluster resource:

$ oc edit ingresses.config/cluster -o yaml

Edit the YAML file:

Sample appsDomain configuration to test.example.com

apiVersion: config.openshift.io/v1
kind: Ingress
metadata:
  name: cluster
spec:
  domain: apps.example.com            (1)
  appsDomain: <test.example.com>      (2)

1	Specifies the default domain. You cannot modify the default domain after installation.
2	Optional: Domain for OKD infrastructure to use for application routes. Instead of the default prefix, `apps`, you can use an alternative prefix like `test`.

Verify that an existing route contains the domain name specified in the appsDomain field by exposing the route and verifying the route domain change:

Wait for the openshift-apiserver finish rolling updates before exposing the route.

Expose the route:

$ oc expose service hello-openshift
route.route.openshift.io/hello-openshift exposed

Example output:

$ oc get routes
NAME              HOST/PORT                                   PATH   SERVICES          PORT       TERMINATION   WILDCARD
hello-openshift   hello_openshift-<my_project>.test.example.com
hello-openshift   8080-tcp                 None

Converting HTTP header case

HAProxy 2.2 lowercases HTTP header names by default, for example, changing Host: xyz.com to host: xyz.com. If legacy applications are sensitive to the capitalization of HTTP header names, use the Ingress Controller spec.httpHeaders.headerNameCaseAdjustments API field for a solution to accommodate legacy applications until they can be fixed.

Because OKD 4.8 includes HAProxy 2.2, make sure to add the necessary configuration by using spec.httpHeaders.headerNameCaseAdjustments before upgrading.

Prerequisites

You have installed the OpenShift CLI (oc).
You have access to the cluster as a user with the cluster-admin role.

Procedure

As a cluster administrator, you can convert the HTTP header case by entering the oc patch command or by setting the HeaderNameCaseAdjustments field in the Ingress Controller YAML file.

Specify an HTTP header to be capitalized by entering the oc patch command.

Enter the oc patch command to change the HTTP host header to Host:

$ oc -n openshift-ingress-operator patch ingresscontrollers/default --type=merge --patch='{"spec":{"httpHeaders":{"headerNameCaseAdjustments":["Host"]}}}'

Annotate the route of the application:
```
$ oc annotate routes/my-application haproxy.router.openshift.io/h1-adjust-case=true
```
The Ingress Controller then adjusts the host request header as specified.

Specify adjustments using the HeaderNameCaseAdjustments field by configuring the Ingress Controller YAML file.

The following example Ingress Controller YAML adjusts the host header to Host for HTTP/1 requests to appropriately annotated routes:

Example Ingress Controller YAML

apiVersion: operator.openshift.io/v1
kind: IngressController
metadata:
  name: default
  namespace: openshift-ingress-operator
spec:
  httpHeaders:
    headerNameCaseAdjustments:
    - Host

The following example route enables HTTP response header name case adjustments using the haproxy.router.openshift.io/h1-adjust-case annotation:

Example route YAML

apiVersion: route.openshift.io/v1
kind: Route
metadata:
  annotations:
    haproxy.router.openshift.io/h1-adjust-case: true (1)
  name: my-application
  namespace: my-application
spec:
  to:
    kind: Service
    name: my-application

1	Set `haproxy.router.openshift.io/h1-adjust-case` to true.

Additional resources

Configuring a custom PKI

Ingress Operator in OKD

OKD Ingress Operator

The Ingress configuration asset

Ingress Controller configuration parameters

Ingress Controller TLS security profiles

Understanding TLS security profiles

Configuring the TLS security profile for the Ingress Controller

Ingress controller endpoint publishing strategy

View the default Ingress Controller

View Ingress Operator status

View Ingress Controller logs

View Ingress Controller status

Configuring the Ingress Controller

Setting a custom default certificate

Removing a custom default certificate

Scaling an Ingress Controller

Configuring Ingress access logging

Setting Ingress Controller thread count

Ingress Controller sharding

Configuring Ingress Controller sharding by using route labels

Configuring Ingress Controller sharding by using namespace labels

Configuring an Ingress Controller to use an internal load balancer

Configuring global access for an Ingress Controller on GCP

Configuring the default Ingress Controller for your cluster to be internal

Configuring the route admission policy

Using wildcard routes

Using X-Forwarded headers

Example use cases

Enabling HTTP/2 Ingress connectivity

Configuring the PROXY protocol for an Ingress Controller

Specifying an alternative cluster domain using the appsDomain option

Converting HTTP header case

Additional resources