Ingress

Overview of Ingress

Ingress exposes HTTP and HTTPS routes from outside the cluster to services within the cluster. Traffic routing is controlled by rules defined on the Ingress resource.

Here is a simple diagram where an Ingress sends all its traffic to one Service:

See also

Refer to Kubernetes Ingress documentation for more information.

Why use Ingress?

You can use Ingress to make internal services reachable from outside the cluster. It saves static IPs, as you will not need to declare multiple LoadBalancer services.

     apiVersion: networking.k8s.io/v1beta1
     kind: Ingress
     metadata:
     name: test-ingress
     spec:
     rules:
     - http:
         paths:
         - path: /testpath
             pathType: Prefix
             backend:
             serviceName: test
             servicePort: 80

As with all other Kubernetes resources, an Ingress needs apiVersion, kind, and metadata fields.

The Ingress spec has all the information needed to configure a load balancer or proxy server. Most importantly, it contains a list of rules matched against all incoming requests. Ingress resource only supports rules for directing HTTP traffic.

Ingress Rules:

Each HTTP rule contains the following information:

• An optional host. In this example, no host is specified, so the rule applies to all inbound HTTP traffic through the IP address specified. If a host is provided (for example, foo.bar.com), the rules apply to that host.
• A list of paths (for example, /testpath), each of which has an associated backend defined with a serviceName and servicePort. Both the host and path must match the content of an incoming request before the load balancer directs traffic to the referenced Service.
• A backend is a combination of Service and port names. HTTP (and HTTPS) requests to the Ingress that match the host and path of the rule are sent to the listed backend.

Default backend:

An Ingress with no rules sends all traffic to a single default backend. The default backend is typically a configuration option of the Ingress controller and is not specified in your Ingress resources.

If none of the hosts or paths match the HTTP request in the Ingress objects, the traffic is routed to your default backend.

Path types:

Each path in an Ingress has a corresponding path type. There are three supported path types:

• Default: With this path type, matching is up to the IngressClass. Implementations can treat this as a separate pathType or treat it identically to prefix or Exact path types.
• Exact: Matches the URL path exactly and with case sensitivity.
• Prefix: Matches based on a URL path prefix split by /. Matching is case sensitive and done on a path element-by-element basis. A path element refers to the list of labels in the path split by the / separator. A request is a match for path p if every p is an element-wise prefix of p of the request path.

Types of Ingress

Note

If any of the examples below differ from the linked YAML, GitHub has the most recent version.

• Single Service Ingress: You can expose a single service by specifying default backend with no rules. For example:

  The most up-to-date version of this example is here: single-service-ingress.yaml

  apiVersion: extensions/v1beta1
  kind: Ingress
  metadata:
    name: ingress1
    namespace: default
    annotations:
      # Provide an IP address from the external VLAN on your BIG-IP device
      virtual-server.f5.com/ip: "10.190.25.70"
      # Specify the BIG-IP partition containing the virtual server
      virtual-server.f5.com/partition: "k8s"
  spec:
    backend:
      # The name of the Kubernetes Service you want to expose to external traffic
      serviceName: myService
      servicePort: 80
  

• Simple Fanout : A fanout configuration routes traffic from a single IP address to more than one Service, based on the HTTP URI being requested.

  The most up-to-date version of this example is here: simple-ingress-fanout.yaml

  apiVersion: extensions/v1beta1
  kind: Ingress
  metadata:
    name: ing-fanout
    namespace: default
    annotations:
      # IP address of a BIG-IP pool member
      virtual-server.f5.com/ip: "1.2.3.4"
      # BIG-IP partition
      virtual-server.f5.com/partition: "k8s"
      # Load balancing algorithm
      virtual-server.f5.com/balance: "round-robin"
  spec:
    rules:
    - host: mysite.example.com
      http:
        paths:
        - path: /mysite/app1
          backend:
            serviceName: myService1
            servicePort: 80
        - path: /mysite/app2
          backend:
            serviceName: myService2
            servicePort: 80
  

• Name Based Virtual Hosting: Name-based virtual hosts support routing HTTP traffic to multiple host names at the same IP address.

  The most up-to-date version of this example is here: name-based-ingress.yaml

  apiVersion: extensions/v1beta1
  kind: Ingress
  metadata:
  name: ing-virtual-hosting
  namespace: default
  annotations:
    # BIG-IP pool member IP address
    virtual-server.f5.com/ip: "1.2.3.4"
    # BIG-IP partition
    virtual-server.f5.com/partition: "k8s"
    # Load balancing algorithm
    virtual-server.f5.com/balance: "round-robin"
    # Specify the port you want to handle requests
    virtual-server.f5.com/http-port: "80"
  spec:
  rules:
  # URL
  - host: mysite.example.com
    http:
      # path to Service from URL
      paths:
        - path: /myApp1
          backend:
            serviceName: myService1
            servicePort: 80
  # URL
  - host: yoursite.example.com
    http:
      # path to Service from URL
      paths:
        - path: /myApp2
          backend:
            serviceName: myService2
            servicePort: 80
  

• TLS: You can secure an Ingress by specifying a Secret that contains a TLS private key and certificate. Currently the Ingress only supports a single TLS port, 443, and assumes TLS termination.

  The TLS secret must contain keys named tls.crt and tls.key that contain the certificate and private key to use for TLS. For example:

  The most up-to-date version of this example is here: example-secret-tls.yaml

  apiVersion: v1
  kind: Secret
  metadata:
    name: example-secret-tls
    namespace: default
  data:
    tls.crt: base64 encoded cert
    tls.key: base64 encoded key
  type: kubernetes.io/tls
  

  Referencing this secret in an Ingress tells the Ingress controller to secure the channel from the client to the load balancer using TLS. You need to make sure the TLS secret you created came from a certificate that contains a Common Name (CN), also known as a Fully Qualified Domain Name (FQDN) for example.com

  The most up-to-date version of this example is here: single-service-tls-ingress.yaml

  apiVersion: extensions/v1beta1
  kind: Ingress
  metadata:
    name: ingressTLS
    namespace: default
    annotations:
      # Provide an IP address for the BIG-IP pool you want to handle traffic.
      virtual-server.f5.com/ip: "1.2.3.4"
      # Specify the BIG-IP partition containing the virtual server.
      virtual-server.f5.com/partition: "k8s"
      # Allow/deny TLS connections
      ingress.kubernetes.io/ssl-redirect: "true"
      # Allow/deny HTTP connections
      ingress.kubernetes.io/allow-http: "false"
  spec:
    tls:
      # Specifies an already-configured SSL Profile on BIG-IP that should be
      # used for this Ingress.
      # Follows the format "/partition/profile_name".
      - secretName: /Common/clientssl
    backend:
      # The name of a single Kubernetes Service you want to expose to external
      # traffic using TLS
      serviceName: myService
      servicePort: 443
  

• Load balancing: An Ingress controller is bootstrapped with some load balancing policy settings that it applies to all Ingress, such as the load balancing algorithm, backend weight scheme, and others. More advanced load balancing concepts (e.g. persistent sessions, dynamic weights) are not yet exposed through the Ingress. You can instead get these features through the load balancer used for a Service.

How to deploy Ingress

Prerequisites

In order to deploy Ingress, you must have the following:

• An Ingress controller to satisfy an Ingress. Only creating an Ingress resource has no effect.
• Use F5 BIG-IP Container Ingress Services (CIS) as your Ingress Controller. It must be up and running.

Quickstart

1. Create an Ingress resource. In this example, we create two services to demonstrate how the Ingress routes our request. We run two web applications that output a slightly different response.

   kind: Pod
   apiVersion: v1
   metadata:
     name: foo-app
     labels:
       app: foo
   spec:
     containers:
       - name: foo-app
         image: f5/img
         args:
           - "-text=foo"
   
   ---
   
   kind: Service
   apiVersion: v1
   metadata:
     name: foo-service
   spec:
     selector:
       app: foo
     ports:
       - port: 5678 # Default port for image
   

   kind: Pod
   apiVersion: v1
   metadata:
     name: bar-app
     labels:
       app: bar
   spec:
     containers:
       - name: bar-app
         image: f5/img
         args:
           - "-text=bar"
   
   ---
   
   kind: Service
   apiVersion: v1
   metadata:
     name: bar-service
   spec:
     selector:
       app: bar
     ports:
       - port: 5678 # Default port for image
   

2. Create the resources:

   $ kubectl apply f  foo-app.yaml
   $ kubectl apply f bar app.yaml
   

3. Declare an Ingress to route requests to /foo to the first service, and requests to /bar to the second service:

   apiVersion: extensions/v1beta1
   kind: Ingress
   metadata:
   name: example-ingress
   annotations:
       ingress.kubernetes.io/rewrite-target: /
   spec:
   rules:
   - http:
       paths:
           - path: /foo
           backend:
               serviceName: foo-service
               servicePort: 5678
           - path: /bar
           backend:
               serviceName: bar-service
               servicePort: 5678
   

   Note

   Inside your Ingress configuration you can only redirect to services in the same namespace.

4. Create the Ingress in the cluster:

   kubectl create -f ingress.yaml
   

5. Verify that it is working:

   $ curl -kL http://localhost/foo
   foo
   
   $ curl -kL http://localhost/bar
   bar
   
   $ curl -kL http://localhost/notfound
   default backend - 404
   

Ingress Resources

Supported Ingress Annotations

Annotation		Type	Required	Description	Default	Allowed Values
virtual-server.f5.com/ip		string	Required	The IP address you want to assign to the virtual server. Set to “controller-default” if you want to use the default-ingress-ip specified in the Configuration Parameters above.	N/A	numerical IP address “controller-default”
virtual-server.f5.com/partition		string	Optional	The BIG-IP partition in which the Controller should create/update/delete objects for this Ingress.	N/A
kubernetes.io/ingress.class		string	Optional	Tells the Controller it should only manage Ingress resources in the f5 class. If defined, the value must be f5.	f5	“f5”
virtual-server.f5.com/balance		string	Optional	Sets the load balancing mode.	round-robin	Any supported load balancing algorithm
virtual-server.f5.com/http-port		integer	Optional	Specifies the HTTP port.	80
virtual-server.f5.com/https-port		integer	Optional	Specifies the HTTPS port.	443
virtual-server.f5.com/health		JSON object	Optional	Defines a health monitor for the Ingress resource.	N/A
	path	string	Required	The path for the Service specified in the Ingress resource.	N/A
	interval	integer	Required	The interval at which to check the health of the virtual server.	N/A
	timeout	integer	Required	Number of seconds before the check times out.	N/A
	send	string	Required	The send string to set in the health monitor.	N/A
	recv	string	Optional	String or RegEx pattern to match in first 5,120 bytes of backend response.	N/A
	type	string	Optional	Health monitor type. Typically http or https.	http
ingress.kubernetes.io/allow-http		boolean	Optional	Tells the Controller to allow HTTP traffic for HTTPS Ingress resources.	false	“true”, “false”
ingress.kubernetes.io/ssl-redirect		boolean	Optional	Tells the Controller to redirect HTTP traffic to the HTTPS port for HTTPS Ingress resources (see TLS Ingress resources, below).	true	“true”, “false”
virtual-server.f5.com/serverssl		string	Optional	The name of a pre-configured server ssl profile on the BIG-IP system.	N/A
virtual-server.f5.com/rewrite-app-root		string	Optional	Root path redirection for the application.	N/A
virtual-server.f5.com/rewrite-target-url		string	Optional	URL host, path, or host and path to be rewritten.	N/A
virtual-server.f5.com/allow-source-range		string	Optional	Comma separated list of CIDR addresses to allow inbound to Ingress services.	N/A	Comma separated, CIDR formatted, IP addresses. ex. 1.2.3.4/32,2.2.2.0/24

Ingress Health Monitors

To configure health monitors on your Ingress resource, define the virtual-server.f5.com/health annotation with a JSON object. Provide an array for each path specified in the Ingress resource.

For example

{
"path": "ServiceName/path",
"send": "<send string to set in the health monitor>",
"interval": <health check interval>,
"timeout": <number of seconds before the check has timed out>
}

Use a BIG-IP SSL profile or Secret

You can secure an Ingress using BIG-IP SSL profiles or Kubernetes Secrets.

1. Specify the SSL profile(s) or the Secret containing the cert and key in the spec.tls section of the Ingress resource.
2. Add the ingress.kubernetes.io/ssl-redirect annotation (OPTIONAL; defaults to "true").
3. Add the ingress.kubernetes.io/allow-http annotation (OPTIONAL; defaults to "false").

Note

• You can specify one or more SSL profiles in your Ingress resource.
• If you specify a spec.tls section without providing the TLS Ingress properties, the BIG-IP device uses its local traffic policies to redirect HTTP requests to HTTPS.

The table below shows how the Controller behaves for different combinations of the ingress.kubernetes.io/ssl-redirect and ingress.kubernetes.io/allow-http settings.

State	sslRedirect	allowHttp	Description
1	F	F	Just HTTPS, nothing on HTTP
2	T	F	HTTP redirects to HTTPS
2	T	T	Honor sslRedirect == true
3	F	T	Both HTTP and HTTPS

TLS Ingress example using a BIG-IP SSL profile

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: ingressTLS
  namespace: default
  annotations:
    virtual-server.f5.com/ip: "1.2.3.4"
    virtual-server.f5.com/partition: "k8s"
    ingress.kubernetes.io/ssl-redirect: "true"
    ingress.kubernetes.io/allow-http: "false"
spec:
  tls:
    # Provide the name of the BIG-IP SSL profile you want to use.
    - secretName: /Common/clientssl
  backend:
    # Provide the name of a single Kubernetes Service you want to expose to external
    # traffic using TLS
    serviceName: myService
    servicePort: 443

f5-k8s-ingress-tls.yaml

TLS Ingress example using a Secret

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: ingressTLS
  namespace: default
  annotations:
    virtual-server.f5.com/ip: "1.2.3.4"
    virtual-server.f5.com/partition: "k8s"
    ingress.kubernetes.io/ssl-redirect: "true"
    ingress.kubernetes.io/allow-http: "false"
spec:
  tls:
    # Provide the name of the Secret you want to use.
    - secretName: myTLSSecret
  backend:
    # Provide the name of a single Kubernetes Service you want to expose to external
    # traffic using TLS
    serviceName: myService
    servicePort: 443


apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: no-rules-map
spec:
  tls:
  - secretName: testsecret
  backend:
    serviceName: s1
    servicePort: 80

f5-k8s-ingress-tls-secret.yaml

See also

Refer to the Kubernetes TLS Ingress documentation for details regarding supported port(s) and termination.

Exposing Headless Service using Ingress

You can expose a Kubernetes headless service using ingress as shown in the example below.

Note

• IP addresses specified in the endpoints yaml file can be external or pod IP addresses, which need to be updated manually.
• You can only add the IP addresses in the endpoints; host-names are not supported.
• You can only expose headless service when CIS is deployed in ClusterIP mode.

Exposing Sample Headless Service using ingress

apiVersion: v1
kind: Endpoints
metadata:
  labels:
    headless-app: app-1
  name: svc-1
subsets:
  - addresses:
      # Following ip addresses can be external or pod IP Addresses, which needs to be updated manually
      - ip: 192.168.0.101
        nodeName: node-1
      - ip: 192.168.0.102
        nodeName: node-2
      - ip: 192.168.0.103
        nodeName: node-3
    ports:
      - name: port-app-1
        port: 8080
        protocol: TCP
---

apiVersion: v1
kind: Service
metadata:
  name: svc-1
  labels:
    headless-app: app-1
spec:
  # Specify clusterIP as None to create a headless service
  clusterIP: None
  ports:
    - port: 8080
      targetPort: 8080
      protocol: TCP
      name: port-app-1
---

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: svc-1-ingress
  annotations:
    kubernetes.io/ingress.class: f5
    virtual-server.f5.com/balance: least-connections-node
    virtual-server.f5.com/ip: 10.8.10.3
    virtual-server.f5.com/partition: test
spec:
  rules:
    - http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              serviceName: svc-1
              servicePort: 8080

sample-headless-service-ingress.yaml

See also

Refer to the Kubernetes Headless Service documentation .

Examples Repository

View more examples on GitHub.

Note

To provide feedback on Container Ingress Services or this documentation, you can file a GitHub Issue.