Ingress Operator in OKD

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

  1. apiVersion: config.openshift.io/v1
  2. kind: Ingress
  3. metadata:
  4.   name: cluster
  5. spec:
  6.   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.

ParameterDescription

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.

appsDomain

appsDomain is an optional domain for AWS infrastructure to use instead of the one specified in the domain field when a Route is created without specifying an explicit host. If a value is entered for appsDomain, this value is used to generate default host values for the Route. Unlike domain, appsDomain can be modified after installation. You can use this parameter only if you set up a new Ingress Controller that uses a wildcard certificate.

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:

  1. nodePlacement:
  2.  nodeSelector:
  3.    matchLabels:
  4.      kubernetes.io/os: linux
  5.  tolerations:
  6.  - effect: NoSchedule
  7.    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 1.3.

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

The Ingress Operator converts the TLS 1.0 of an Old or Custom profile to 1.1.

clientTLS

clientTLS authenticates client access to the cluster and services; as a result, mutual TLS authentication is enabled. If not set, then client TLS is not enabled.

clientTLS has the required subfields, spec.clientTLS.clientCertificatePolicy and spec.clientTLS.ClientCA.

The ClientCertificatePolicy subfield accepts one of the two values: Required or Optional. The ClientCA subfield specifies a config map that is in the openshift-config namespace. The config map should contain a CA certificate bundle. The AllowedSubjectPatterns is an optional value that specifies a list of regular expressions, which are matched against the distinguished name on a valid client certificate to filter requests. The regular expressions must use PCRE syntax. At least one pattern must match a client certificate’s distinguished name; otherwise, the ingress controller rejects the certificate and denies the connection. If not specified, the ingress controller does not reject certificates based on the distinguished name.

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.

httpErrorCodePages

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

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.

  • clientTimeout specifies how long a connection is held open while waiting for a client response. If unset, the default timeout is 30s.

  • serverFinTimeout specifies how long a connection is held open while waiting for the server response to the client that is closing the connection. If unset, the default timeout is 1s.

  • serverTimeout specifies how long a connection is held open while waiting for a server response. If unset, the default timeout is 30s.

  • clientFinTimeout specifies how long a connection is held open while waiting for the client response to the server closing the connection. If unset, the default timeout is 1s.

  • tlsInspectDelay specifies how long the router can hold data to find a matching route. Setting this value too short can cause the router to fall back to the default certificate for edge-terminated or reencrypted routes, even when using a better matched certificate. If unset, the default inspect delay is 5s.

  • tunnelTimeout specifies how long a tunnel connection, including websockets, remains open while the tunnel is idle. If unset, the default timeout is 1h.

logEmptyRequests

logEmptyRequests specifies connections for which no request is received and logged. These empty requests come from load balancer health probes or web browser speculative connections (preconnect) and logging these requests can be undesirable. However, these requests can be caused by network errors, in which case logging empty requests can be useful for diagnosing the errors. These requests can be caused by port scans, and logging empty requests can aid in detecting intrusion attempts. Allowed values for this field are Log and Ignore. The default value is Log.

The LoggingPolicy type accepts either one of two values:

  • Log: Setting this value to Log indicates that an event should be logged.

  • Ignore: Setting this value to Ignore sets the dontlognull option in the HAproxy configuration.

HTTPEmptyRequestsPolicy

HTTPEmptyRequestsPolicy describes how HTTP connections are handled if the connection times out before a request is received. Allowed values for this field are Respond and Ignore. The default value is Respond.

The HTTPEmptyRequestsPolicy type accepts either one of two values:

  • Respond: If the field is set to Respond, the Ingress Controller sends an HTTP 400 or 408 response, logs the connection if access logging is enabled, and counts the connection in the appropriate metrics.

  • Ignore: Setting this option to Ignore adds the http-ignore-probes parameter in the HAproxy configuration. If the field is set to Ignore, the Ingress Controller closes the connection without sending a response, then logs the connection, or incrementing metrics.

These connections come from load balancer health probes or web browser speculative connections (preconnect) and can be safely ignored. However, these requests can be caused by network errors, so setting this field to Ignore can impede detection and diagnosis of problems. These requests can be caused by port scans, in which case logging empty requests can aid in detecting intrusion attempts.

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:

Table 1. TLS security profiles
ProfileDescription

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.

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.

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

  1. apiVersion: config.openshift.io/v1
  2. kind: IngressController
  3.  ...
  4. spec:
  5.   tlsSecurityProfile:
  6.     old: {}
  7.     type: Old
  8.  ...

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 HAProxy Ingress Controller image supports TLS 1.3 and the Modern profile.

The Ingress Operator also converts the TLS 1.0 of an Old or Custom profile to 1.1.

Prerequisites

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

Procedure

  1. Edit the IngressController CR in the openshift-ingress-operator project to configure the TLS security profile:

    1. $ oc edit IngressController default -n openshift-ingress-operator

  2. Add the spec.tlsSecurityProfile field:

    Sample IngressController CR for a Custom profile

    1. apiVersion: operator.openshift.io/v1
    2. kind: IngressController
    3.  ...
    4. spec:
    5.   tlsSecurityProfile:
    6.     type: Custom (1)
    7.     custom: (2)
    8.       ciphers: (3)
    9.       - ECDHE-ECDSA-CHACHA20-POLY1305
    10.       - ECDHE-RSA-CHACHA20-POLY1305
    11.       - ECDHE-RSA-AES128-GCM-SHA256
    12.       - ECDHE-ECDSA-AES128-GCM-SHA256
    13.       minTLSVersion: VersionTLS11
    14.  ...
    1Specify the TLS security profile type (Old, Intermediate, or Custom). The default is Intermediate.
    2Specify the appropriate field for the selected type:

    • old: {}

    • intermediate: {}

    • custom:

    3For the custom type, specify a list of TLS ciphers and minimum accepted TLS version.

  3. Save the file to apply the changes.

Verification

  • Verify that the profile is set in the IngressController CR:

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

    Example output

    1. Name:         default
    2. Namespace:    openshift-ingress-operator
    3. Labels:       <none>
    4. Annotations:  <none>
    5. API Version:  operator.openshift.io/v1
    6. Kind:         IngressController
    7.  ...
    8. Spec:
    9.  ...
    10.   Tls Security Profile:
    11.     Custom:
    12.       Ciphers:
    13.         ECDHE-ECDSA-CHACHA20-POLY1305
    14.         ECDHE-RSA-CHACHA20-POLY1305
    15.         ECDHE-RSA-AES128-GCM-SHA256
    16.         ECDHE-ECDSA-AES128-GCM-SHA256
    17.       Min TLS Version:  VersionTLS11
    18.     Type:               Custom
    19.  ...

Configuring mutual TLS authentication

You can configure the Ingress Controller to enable mutual TLS (mTLS) authentication by setting a spec.clientTLS value. The clientTLS value configures the Ingress Controller to verify client certificates. This configuration includes setting a clientCA value, which is a reference to a config map. The config map contains the PEM-encoded CA certificate bundle that is used to verify a client’s certificate. Optionally, you can configure a list of certificate subject filters.

If the clientCA value specifies an X509v3 certificate revocation list (CRL) distribution point, the Ingress Operator downloads the CRL and configures the Ingress Controller to acknowledge it. Requests that do not provide valid certificates are rejected.

Prerequisites

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

Procedure

  1. Create a config map that is in the openshift-config namespace:

    1. $ oc create configmap router-ca-certs-default --from-file=ca-bundle.pem=client-ca.crt -n openshift-config

    The config map data key must be ca-bundle.pem, and the data value must be a CA certificate in PEM format.

  2. Edit the IngressController resource in the openshift-ingress-operator project:

    1. $ oc edit IngressController default -n openshift-ingress-operator

  3. Add the spec.clientTLS field and subfields to configure mutual TLS:

    Sample IngressController CR for a clientTLS profile that specifies filtering patterns

    1.   apiVersion: operator.openshift.io/v1
    2.   kind: IngressController
    3.   metadata:
    4.     name: default
    5.     namespace: openshift-ingress-operator
    6.   spec:
    7.     clientTLS:
    8.       clientCertificatePolicy: Required
    9.       clientCA:
    10.         name: router-ca-certs-default
    11.       allowedSubjectPatterns:
    12.       - "^/CN=example.com/ST=NC/C=US/O=Security/OU=OpenShift$"

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.

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:

    1. $ 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:

    1. $ oc describe clusteroperators/ingress

View Ingress Controller logs

You can view your Ingress Controller logs.

Procedure

  • View your Ingress Controller logs:

    1. $ 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:

    1. $ 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:

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

    Example output

    1. NAME      AGE
    2. 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.

  1. Create a Secret resource containing the custom certificate in the openshift-ingress namespace using the tls.crt and tls.key files.

    1. $ oc --namespace openshift-ingress create secret tls custom-certs-default --cert=tls.crt --key=tls.key

  2. Update the IngressController CR to reference the new certificate secret:

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

  3. Verify the update was effective:

    1. $ oc get --namespace openshift-ingress-operator ingresscontrollers/default \
    2.   --output jsonpath='{.spec.defaultCertificate}'

    Example output

    1. map[name:custom-certs-default]

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

    1. apiVersion: operator.openshift.io/v1
    2. kind: IngressController
    3. metadata:
    4.   name: default
    5.   namespace: openshift-ingress-operator
    6. spec:
    7.   defaultCertificate:
    8.     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.

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

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

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

    Example output

    1. 2

  2. 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:

    1. $ oc patch -n openshift-ingress-operator ingresscontroller/default --patch '{"spec":{"replicas": 3}}' --type=merge

    Example output

    1. ingresscontroller.operator.openshift.io/default patched

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

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

    Example output

    1. 3

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

    1. apiVersion: operator.openshift.io/v1
    2. kind: IngressController
    3. metadata:
    4.   name: default
    5.   namespace: openshift-ingress-operator
    6. spec:
    7.   replicas: 3               (1)
    1If 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

  • Log in as a user with cluster-admin privileges.

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:

    1. apiVersion: operator.openshift.io/v1
    2. kind: IngressController
    3. metadata:
    4.   name: default
    5.   namespace: openshift-ingress-operator
    6. spec:
    7.   replicas: 2
    8.   endpointPublishingStrategy:
    9.     type: NodePortService (1)
    10.   logging:
    11.     access:
    12.       destination:
    13.         type: Container
    1NodePortService is not required to configure Ingress access logging to a sidecar. Ingress logging is compatible with any endpointPublishingStrategy.

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

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

    Example output

    1. 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:

    1. apiVersion: operator.openshift.io/v1
    2. kind: IngressController
    3. metadata:
    4.   name: default
    5.   namespace: openshift-ingress-operator
    6. spec:
    7.   replicas: 2
    8.   endpointPublishingStrategy:
    9.     type: NodePortService
    10.   logging:
    11.     access:
    12.       destination:
    13.         type: Syslog
    14.         syslog:
    15.           address: 1.2.3.4
    16.           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:

    1. apiVersion: operator.openshift.io/v1
    2. kind: IngressController
    3. metadata:
    4.   name: default
    5.   namespace: openshift-ingress-operator
    6. spec:
    7.   replicas: 2
    8.   endpointPublishingStrategy:
    9.     type: NodePortService
    10.   logging:
    11.     access:
    12.       destination:
    13.         type: Syslog
    14.         syslog:
    15.           address: 1.2.3.4
    16.           port: 10514
    17.       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:

    1. apiVersion: operator.openshift.io/v1
    2. kind: IngressController
    3. metadata:
    4.   name: default
    5.   namespace: openshift-ingress-operator
    6. spec:
    7.   replicas: 2
    8.   endpointPublishingStrategy:
    9.     type: NodePortService
    10.   logging:
    11.     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:

    1. $ 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

  1. Edit the router-internal.yaml file:

    1. # cat router-internal.yaml
    2. apiVersion: v1
    3. items:
    4. - apiVersion: operator.openshift.io/v1
    5.   kind: IngressController
    6.   metadata:
    7.     name: sharded
    8.     namespace: openshift-ingress-operator
    9.   spec:
    10.     domain: <apps-sharded.basedomain.example.net>
    11.     nodePlacement:
    12.       nodeSelector:
    13.         matchLabels:
    14.           node-role.kubernetes.io/worker: ""
    15.     routeSelector:
    16.       matchLabels:
    17.         type: sharded
    18.   status: {}
    19. kind: List
    20. metadata:
    21.   resourceVersion: ""
    22.   selfLink: ""

  2. Apply the Ingress Controller router-internal.yaml file:

    1. # 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.

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

  1. Edit the router-internal.yaml file:

    1. # cat router-internal.yaml

    Example output

    1. apiVersion: v1
    2. items:
    3. - apiVersion: operator.openshift.io/v1
    4.   kind: IngressController
    5.   metadata:
    6.     name: sharded
    7.     namespace: openshift-ingress-operator
    8.   spec:
    9.     domain: <apps-sharded.basedomain.example.net>
    10.     nodePlacement:
    11.       nodeSelector:
    12.         matchLabels:
    13.           node-role.kubernetes.io/worker: ""
    14.     namespaceSelector:
    15.       matchLabels:
    16.         type: sharded
    17.   status: {}
    18. kind: List
    19. metadata:
    20.   resourceVersion: ""
    21.   selfLink: ""

  2. Apply the Ingress Controller router-internal.yaml file:

    1. # 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.

See the Kubernetes Services documentation for implementation details.

Prerequisites

  • Install the OpenShift CLI (oc).

  • Log in as a user with cluster-admin privileges.

Procedure

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

    1. apiVersion: operator.openshift.io/v1
    2. kind: IngressController
    3. metadata:
    4.   namespace: openshift-ingress-operator
    5.   name: <name> (1)
    6. spec:
    7.   domain: <domain> (2)
    8.   endpointPublishingStrategy:
    9.     type: LoadBalancerService
    10.     loadBalancer:
    11.       scope: Internal (3)
    1Replace <name> with a name for the IngressController object.
    2Specify the domain for the application published by the controller.
    3Specify a value of Internal to use an internal load balancer.

  2. Create the Ingress Controller defined in the previous step by running the following command:

    1. $ oc create -f <name>-ingress-controller.yaml (1)
    1Replace <name> with the name of the IngressController object.

  3. Optional: Confirm that the Ingress Controller was created by running the following command:

    1. $ 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

  1. Configure the Ingress Controller resource to allow global access.

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

    1. Configure the Ingress Controller resource:

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

    2. Edit the YAML file:

      Sample clientAccess configuration to Global

      1.   spec:
      2.     endpointPublishingStrategy:
      3.       loadBalancer:
      4.         providerParameters:
      5.           gcp:
      6.             clientAccess: Global (1)
      7.           type: GCP
      8.         scope: Internal
      9.       type: LoadBalancerService
      1Set gcp.clientAccess to Global.

    3. Save the file to apply the changes.

  2. Run the following command to verify that the service allows global access:

    1. $ 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.

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.

Prerequisites

  • Install the OpenShift CLI (oc).

  • Log in as a user with cluster-admin privileges.

Procedure

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

    1. $ oc replace --force --wait --filename - <<EOF
    2. apiVersion: operator.openshift.io/v1
    3. kind: IngressController
    4. metadata:
    5.   namespace: openshift-ingress-operator
    6.   name: default
    7. spec:
    8.   endpointPublishingStrategy:
    9.     type: LoadBalancerService
    10.     loadBalancer:
    11.       scope: Internal
    12. 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:

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

    Sample Ingress Controller configuration

    1. spec:
    2.   routeAdmission:
    3.     namespaceOwnership: InterNamespaceAllowed
    4. ...

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

    1. apiVersion: operator.openshift.io/v1
    2. kind: IngressController
    3. metadata:
    4.   name: default
    5.   namespace: openshift-ingress-operator
    6. spec:
    7.   routeAdmission:
    8.     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

  1. Configure the wildcard policy.

    1. Use the following command to edit the IngressController resource:

      1. $ oc edit IngressController

    2. Under spec, set the wildcardPolicy field to WildcardsDisallowed or WildcardsAllowed:

      1. spec:
      2.   routeAdmission:
      3.     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

  1. Configure the HTTPHeaders field for the Ingress Controller.

    1. Use the following command to edit the IngressController resource:

      1. $ oc edit IngressController

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

      1. apiVersion: operator.openshift.io/v1
      2. kind: IngressController
      3. metadata:
      4.   name: default
      5.   namespace: openshift-ingress-operator
      6. spec:
      7.   httpHeaders:
      8.     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.

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:

    1. $ 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:

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

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

    1. apiVersion: v1
    2. kind: IngressController
    3. metadata:
    4.   annotations:
    5.     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.

To prevent connection failure, configure both the Ingress Controller and the load balancer to use the PROXY protocol.

Prerequisites

  • You created an Ingress Controller.

Procedure

  1. Edit the Ingress Controller resource:

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

  2. 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

      1.   spec:
      2.     endpointPublishingStrategy:
      3.       hostNetwork:
      4.         protocol: PROXY
      5.       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

      1.   spec:
      2.     endpointPublishingStrategy:
      3.       nodePort:
      4.         protocol: PROXY
      5.       type: NodePortService

Configuring application domain for the Ingress Controller Operator on AWS

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 AWS infrastructure 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 on AWS infrastructure.

  • You installed the oc command line interface.

Procedure

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

    1. Edit the Ingress Controller Operator:

      1. $ oc edit ingresses.config/cluster -o yaml

    2. Edit the YAML file:

      Sample appsDomain configuration to test.example.com

      1. apiVersion: config.openshift.io/v1
      2. kind: Ingress
      3. metadata:
      4.   name: cluster
      5. spec:
      6.   domain: apps.example.com            (1)
      7.   appsDomain: <test.example.com>      (2)
      1Default domain
      2Optional: Domain for AWS infrastructure to use for application routes. Instead of the default prefix, apps, you can use an alternative prefix like test.

  2. 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.

    1. Expose the route:

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

      Example output:

      1. $ oc get routes
      2. NAME              HOST/PORT                                   PATH   SERVICES          PORT       TERMINATION   WILDCARD
      3. hello-openshift   hello_openshift-<my_project>.test.example.com
      4. 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 4.9 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.

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

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

    2. Annotate the route of the application:

      1. $ 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.

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

      Example Ingress Controller YAML

      1. apiVersion: operator.openshift.io/v1
      2. kind: IngressController
      3. metadata:
      4.   name: default
      5.   namespace: openshift-ingress-operator
      6. spec:
      7.   httpHeaders:
      8.     headerNameCaseAdjustments:
      9.     - Host

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

      Example route YAML

      1. apiVersion: route.openshift.io/v1
      2. kind: Route
      3. metadata:
      4.   annotations:
      5.     haproxy.router.openshift.io/h1-adjust-case: true (1)
      6.   name: my-application
      7.   namespace: my-application
      8. spec:
      9.   to:
      10.     kind: Service
      11.     name: my-application
      1Set haproxy.router.openshift.io/h1-adjust-case to true.

Customizing HAProxy error code response pages

As a cluster administrator, you can specify a custom error code response page for either 503, 404, or both error pages. The HAProxy router serves a 503 error page when the application pod is not running or a 404 error page when the requested URL does not exist. For example, if you customize the 503 error code response page, then the page is served when the application pod is not running, and the default 404 error code HTTP response page is served by the HAProxy router for an incorrect route or a non-existing route.

Custom error code response pages are specified in a config map then patched to the Ingress Controller. The config map keys have two available file names as follows: error-page-503.http and error-page-404.http.

Custom HTTP error code response pages must follow the HAProxy HTTP error page configuration guidelines. Here is an example of the default OKD HAProxy router http 503 error code response page. You can use the default content as a template for creating your own custom page.

By default, the HAProxy router serves only a 503 error page when the application is not running or when the route is incorrect or non-existent. This default behavior is the same as the behavior on OKD 4.8 and earlier. If a config map for the customization of an HTTP error code response is not provided, and you are using a custom HTTP error code response page, the router serves a default 404 or 503 error code response page.

If you use the OKD default 503 error code page as a template for your customizations, the headers in the file require an editor that can use CRLF line endings.

Procedure

  1. Create a config map named my-custom-error-code-pages in the openshift-config namespace:

    1. $ oc -n openshift-config create configmap my-custom-error-code-pages \
    2. --from-file=error-page-503.http \
    3. --from-file=error-page-404.http

    If you do not specify the correct format for the custom error code response page, a router pod outage occurs. To resolve this outage, you must delete or correct the config map and delete the affected router pods so they can be recreated with the correct information.

  2. Patch the Ingress Controller to reference the my-custom-error-code-pages config map by name:

    1. $ oc patch -n openshift-ingress ingresscontroller/default --patch '{"spec":{"httpErrorCodePages": "my-custom-error-code-pages"}}' --type=merge

    The Ingress Operator copies the my-custom-error-code-pages config map from the openshift-config namespace to the openshift-ingress namespace. The Operator names the config map according to the pattern, <your_ingresscontroller_name>-errorpages, in the openshift-ingress namespace.

  3. Display the copy:

    1. $ oc get cm default-errorpages -n openshift-ingress

    Example output

    1. NAME                       DATA   AGE
    2. default-errorpages         2      25s  (1)
    1The example config map name is default-errorpages because the default Ingress Controller custom resource (CR) was patched.

  4. Confirm that the config map containing the custom error response page mounts on the router volume where the config map key is the filename that has the custom HTTP error code response:

    • For 503 custom HTTP custom error code response:

      1. $ oc -n openshift-ingress rsh <router_pod> cat /var/lib/haproxy/conf/error_code_pages/error-page-503.http

    • For 404 custom HTTP custom error code response:

      1. $ oc -n openshift-ingress rsh <router_pod> cat /var/lib/haproxy/conf/error_code_pages/error-page-404.http

Verification

Verify your custom error code HTTP response:

  1. Create a test project and application:

    1.  $ oc new-project test-ingress
    1. $ oc new-app django-psql-example

  2. For 503 custom http error code response:

    1. Stop all the pods for the application.

    2. Run the following curl command or visit the route hostname in the browser:

      1. $ curl -vk <route_hostname>

  3. For 404 custom http error code response:

    1. Visit a non-existent route or an incorrect route.

    2. Run the following curl command or visit the route hostname in the browser:

      1. $ curl -vk <route_hostname>

  4. Check if the errorfile attribute is properly in the haproxy.config file:

    1. $ oc -n openshift-ingress rsh <router> cat /var/lib/haproxy/conf/haproxy.config | grep errorfile

Additional resources