Kubernetes Ingress Support

Cilium uses the standard Kubernetes Ingress resource definition, with an ingressClassName of cilium. This can be used for path-based routing and for TLS termination. For backwards compatibility, the kubernetes.io/ingress.class annotation with value of cilium is also supported.

Note

The ingress controller creates a Service of LoadBalancer type, so your environment will need to support this.

Cilium allows you to specify load balancer mode for the Ingress resource:

• dedicated: The Ingress controller will create a dedicated loadbalancer for the Ingress.

• shared: The Ingress controller will use a shared loadbalancer for all Ingress resources.

Each load balancer mode has its own benefits and drawbacks. The shared mode saves resources by sharing a single LoadBalancer config across all Ingress resources in the cluster, while the dedicated mode can help to avoid potential conflicts (e.g. path prefix) between resources.

Note

It is possible to change the load balancer mode for an Ingress resource. When the mode is changed, active connections to backends of the Ingress may be terminated during the reconfiguration due to a new load balancer IP address being assigned to the Ingress resource.

This is a step-by-step guide on how to enable the Ingress Controller in an existing K8s cluster with Cilium installed.

Prerequisites

• Cilium must be configured with NodePort enabled, using nodePort.enabled=true or by enabling the kube-proxy replacement with kubeProxyReplacement=true. For more information, see kube-proxy replacement.

• Cilium must be configured with the L7 proxy enabled using l7Proxy=true (enabled by default).

• By default, the Ingress controller creates a Service of LoadBalancer type, so your environment will need to support this. Alternatively, you can change this to NodePort or, since Cilium 1.16+, directly expose the Cilium L7 proxy on the host network.

Installation

HelmCilium CLI

Cilium Ingress Controller can be enabled with helm flag ingressController.enabled set as true. Please refer to Installation using Helm for a fresh installation.

$ helm upgrade cilium ./cilium \
    --namespace kube-system \
    --reuse-values \
    --set ingressController.enabled=true \
    --set ingressController.loadbalancerMode=dedicated
$ kubectl -n kube-system rollout restart deployment/cilium-operator
$ kubectl -n kube-system rollout restart ds/cilium

Cilium can become the default ingress controller by setting the --set ingressController.default=true flag. This will create ingress entries even when the ingressClass is not set.

If you only want to use envoy traffic management feature without Ingress support, you should only enable --enable-envoy-config flag.

$ helm upgrade cilium ./cilium \
    --namespace kube-system \
    --reuse-values \
    --set envoyConfig.enabled=true
$ kubectl -n kube-system rollout restart deployment/cilium-operator
$ kubectl -n kube-system rollout restart ds/cilium

Additionally, the proxy load-balancing feature can be configured with the loadBalancer.l7.backend=envoy flag.

$ helm upgrade cilium ./cilium \
    --namespace kube-system \
    --reuse-values \
    --set loadBalancer.l7.backend=envoy
$ kubectl -n kube-system rollout restart deployment/cilium-operator
$ kubectl -n kube-system rollout restart ds/cilium

Next you can check the status of the Cilium agent and operator:

$ cilium status

Warning

Make sure you install cilium-cli v0.15.0 or later. The rest of instructions do not work with older versions of cilium-cli. To confirm the cilium-cli version that’s installed in your system, run:

cilium version --client

See Cilium CLI upgrade notes for more details.

Install the latest version of the Cilium CLI. The Cilium CLI can be used to install Cilium, inspect the state of a Cilium installation, and enable/disable various features (e.g. clustermesh, Hubble).

LinuxmacOSOther

CILIUM_CLI_VERSION=$(curl -s https://raw.githubusercontent.com/cilium/cilium-cli/main/stable.txt)
CLI_ARCH=amd64
if [ "$(uname -m)" = "aarch64" ]; then CLI_ARCH=arm64; fi
curl -L --fail --remote-name-all https://github.com/cilium/cilium-cli/releases/download/${CILIUM_CLI_VERSION}/cilium-linux-${CLI_ARCH}.tar.gz{,.sha256sum}
sha256sum --check cilium-linux-${CLI_ARCH}.tar.gz.sha256sum
sudo tar xzvfC cilium-linux-${CLI_ARCH}.tar.gz /usr/local/bin
rm cilium-linux-${CLI_ARCH}.tar.gz{,.sha256sum}

Clone the Cilium GitHub repository so that the Cilium CLI can access the latest unreleased Helm chart from the main branch:

git clone git@github.com:cilium/cilium.git
cd cilium

Hubble CLI is also used to observe the traffic in later steps.

LinuxMacOSWindows

Download the latest hubble release:

HUBBLE_VERSION=$(curl -s https://raw.githubusercontent.com/cilium/hubble/master/stable.txt)
HUBBLE_ARCH=amd64
if [ "$(uname -m)" = "aarch64" ]; then HUBBLE_ARCH=arm64; fi
curl -L --fail --remote-name-all https://github.com/cilium/hubble/releases/download/$HUBBLE_VERSION/hubble-linux-${HUBBLE_ARCH}.tar.gz{,.sha256sum}
sha256sum --check hubble-linux-${HUBBLE_ARCH}.tar.gz.sha256sum
sudo tar xzvfC hubble-linux-${HUBBLE_ARCH}.tar.gz /usr/local/bin
rm hubble-linux-${HUBBLE_ARCH}.tar.gz{,.sha256sum}

Supported Ingress Annotations

Name	Description	Default Value
ingress.cilium.io/loadbalancer-mode	The loadbalancer mode for the ingress. Allows a per ingress override of the default set in the Helm value ingressController.loadbalancerMode. Applicable values are dedicated and shared.	dedicated (from Helm chart)
ingress.cilium.io/service-type	The Service type for dedicated Ingress. Applicable values are LoadBalancer and NodePort.	LoadBalancer
ingress.cilium.io/insecure-node-port	The NodePort to use for the HTTP Ingress. Applicable only if ingress.cilium.io/service-type is NodePort. If unspecified, a random NodePort will be allocated by kubernetes.	unspecified
ingress.cilium.io/secure-node-port	The NodePort to use for the HTTPS Ingress. Applicable only if ingress.cilium.io/service-type is NodePort. If unspecified, a random NodePort will be allocated by kubernetes.	unspecified
ingress.cilium.io/host-listener-port	The port to use for the Envoy listener on the host network. Applicable and mandatory only for dedicated Ingress and if host network mode is enabled.	8080
ingress.cilium.io/tls-passthrough	Enable TLS Passthrough mode for this Ingress. Applicable values are enabled and disabled, although boolean-style values will also be accepted. Note that some conditions apply to TLS Passthrough Ingresses, due to how TLS Passthrough works: * A host field must be set in the Ingress * Default backends are ignored * Rules with paths other than / are ignored If all the rules in an Ingress are ignored for these reasons, no Envoy config will be generated and the Ingress will have no effect. Note that this annotation is analogous to the ssl-passthrough on other Ingress controllers.	disabled
ingress.cilium.io/force-https	Enable enforced HTTPS redirects for this Ingress. Applicable values are enabled and disabled, although boolean-style values will also be accepted. Note that if the annotation is not present, this behavior will be controlled by the enforce-ingress-https configuration file setting (or ingressController.enforceHttps in Helm). Any host with TLS config will have redirects to HTTPS configured for each match specified in the Ingress.	unspecified

Additionally, cloud-provider specific annotations for the LoadBalancer Service are supported.

By default, annotations with values beginning with:

• lbipam.cilium.io

• nodeipam.cilium.io

• service.beta.kubernetes.io

• service.kubernetes.io

• cloud.google.com

will be copied from an Ingress object to the generated LoadBalancer Service objects.

This setting is controlled by the Cilium Operator’s ingress-lb-annotation-prefixes config flag, and can be configured in Cilium’s Helm values.yaml using the ingressController.ingressLBAnnotationPrefixes setting.

Please refer to the Kubernetes documentation for more details.

Host network mode

Note

Supported since Cilium 1.16+

Host network mode allows you to expose the Cilium ingress controller (Envoy listener) directly on the host network. This is useful in cases where a LoadBalancer Service is unavailable, such as in development environments or environments with cluster-external loadbalancers.

Note

• Enabling the Cilium ingress controller host network mode automatically disables the LoadBalancer/NodePort type Service mode. They are mutually exclusive.

• The listener is exposed on all interfaces (0.0.0.0 for IPv4 and/or :: for IPv6).

Host network mode can be enabled via Helm:

ingressController:
  enabled: true
  hostNetwork:
    enabled: true

Once enabled, host network ports can be specified with the following methods:

• Shared Ingress: Globally via Helm flags

  • ingressController.hostNetwork.sharedListenerPort: Host network port to expose the Cilium ingress controller Envoy listener. The default port is 8080. If you change it, you should choose a port number higher than 1023 (see Bind to privileged port).

• Dedicated Ingress: Per Ingress resource via annotations

  • ingress.cilium.io/host-listener-port: Host network port to expose the Cilium ingress controller Envoy listener. The default port is 8080 but it can only be used for a single Ingress resource as it needs to be unique per Ingress resource. You should choose a port higher than 1023 (see Bind to privileged port). This annotation is mandatory if the global Cilium ingress controller mode is configured to dedicated (ingressController.loadbalancerMode) or the ingress resource sets the ingress.cilium.io/loadbalancer-mode annotation to dedicated and multiple Ingress resources are deployed.

The default behavior regarding shared or dedicated ingress can be configured via ingressController.loadbalancerMode.

Warning

Be aware that misconfiguration might result in port clashes. Configure unique ports that are still available on all Cilium Nodes where Cilium ingress controller Envoy listeners are exposed.

Bind to privileged port

By default, the Cilium L7 Envoy process does not have any Linux capabilities out-of-the-box and is therefore not allowed to listen on privileged ports.

If you choose a port equal to or lower than 1023, ensure that the Helm value envoy.securityContext.capabilities.keepCapNetBindService=true is configured and to add the capability NET_BIND_SERVICE to the respective Cilium Envoy container via Helm values:

• Standalone DaemonSet mode: envoy.securityContext.capabilities.envoy

• Embedded mode: securityContext.capabilities.ciliumAgent

Configure the following Helm values to allow privileged port bindings in host network mode:

Standalone DaemonSet modeEmbedded mode

ingressController:
  enabled: true
  hostNetwork:
    enabled: true
envoy:
  enabled: true
  securityContext:
    capabilities:
      keepCapNetBindService: true
      envoy:
      # Add NET_BIND_SERVICE to the list (keep the others!)
      - NET_BIND_SERVICE

Deploy Gateway API listeners on subset of nodes

The Cilium ingress controller Envoy listener can be exposed on a specific subset of nodes. This only works in combination with the host network mode and can be configured via a node label selector in the Helm values:

ingressController:
  enabled: true
  hostNetwork:
    enabled: true
    nodes:
      matchLabels:
        role: infra
        component: ingress

This will deploy the Ingress Controller Envoy listener only on the Cilium Nodes matching the configured labels. An empty selector selects all nodes and continues to expose the functionality on all Cilium nodes.

Examples

Please refer to one of the below examples on how to use and leverage Cilium’s Ingress features:

• Ingress HTTP Example
• Ingress gRPC Example
• Ingress Example with TLS Termination
• Defaults certificate for Ingresses