Ingress tutorials
Route HTTP traffic
In this section, you will learn how to define Ingress rules that state how traffic should be routed within your Kubernetes cluster. Ultimately, HAProxy Kubernetes Ingress Controller will implement those rules.
Route HTTP traffic based on the requested hostname Jump to heading
In this section, you’ll learn how to direct traffic based on the hostname the client requests. For example, if they request example.com
, you could route them to a service named example-service
.
To route traffic by hostname:
-
On your DNS server, creat an A record that maps the hostname, for example
example.com
, to your Kubernetes cluster. In a cloud environment, this IP address will be assigned to the cloud load balancer in front of your Kubernetes cluster. In an on-premises environment, this may be the address of an external load balancer like HAProxy, set to load balance traffic across your Kubernetes nodes. -
Define the application you will deploy to Kubernetes by creating
Deployment
andService
resources. Here, we define an example application using thejmalloc/echo-server
Docker container image:example-deployment.yamlyamlapiVersion: apps/v1kind: Deploymentmetadata:labels:run: appname: appspec:replicas: 1selector:matchLabels:run: apptemplate:metadata:labels:run: appspec:containers:- name: appimage: jmalloc/echo-serverports:- containerPort: 8080readinessProbe:httpGet:path: /port: 8080initialDelaySeconds: 5periodSeconds: 5successThreshold: 1---apiVersion: v1kind: Servicemetadata:name: example-servicespec:selector:run: appports:- name: httpprotocol: TCPport: 8080targetPort: 8080example-deployment.yamlyamlapiVersion: apps/v1kind: Deploymentmetadata:labels:run: appname: appspec:replicas: 1selector:matchLabels:run: apptemplate:metadata:labels:run: appspec:containers:- name: appimage: jmalloc/echo-serverports:- containerPort: 8080readinessProbe:httpGet:path: /port: 8080initialDelaySeconds: 5periodSeconds: 5successThreshold: 1---apiVersion: v1kind: Servicemetadata:name: example-servicespec:selector:run: appports:- name: httpprotocol: TCPport: 8080targetPort: 8080 -
Deploy this to your Kubernetes cluster using
kubectl
.nixkubectl apply -f example-deployment.yamlnixkubectl apply -f example-deployment.yaml -
Create an Ingress resource. Include a
host
field in your routing rule. Below, we set the host toexample.com
and the service name toexample-service
:example-ingress.yamlyamlapiVersion: networking.k8s.io/v1kind: Ingressmetadata:name: example-ingressspec:ingressClassName: haproxyrules:- host: "example.com"http:paths:- path: /pathType: Prefixbackend:service:name: example-serviceport:number: 8080example-ingress.yamlyamlapiVersion: networking.k8s.io/v1kind: Ingressmetadata:name: example-ingressspec:ingressClassName: haproxyrules:- host: "example.com"http:paths:- path: /pathType: Prefixbackend:service:name: example-serviceport:number: 8080 -
Deploy this to your Kubernetes cluster using
kubectl
.nixkubectl apply -f example-ingress.yamlnixkubectl apply -f example-ingress.yaml -
If you deployed the ingress controller service using a NodePort, then you can access the example service at the NodePort HTTP port. For example,
http://example.com:30000/
. To find which NodePort port has been assigned, view the service’s status:nixkubectl get service haproxy-kubernetes-ingress --namespace haproxy-controllernixkubectl get service haproxy-kubernetes-ingress --namespace haproxy-controllerPort 80 has been mapped to NodePort 30000:
outputtextNAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGEhaproxy-kubernetes-ingress NodePort 10.101.116.157 <none> 80:30000/TCP,443:31962/TCP,1024:31675/TCP 97moutputtextNAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGEhaproxy-kubernetes-ingress NodePort 10.101.116.157 <none> 80:30000/TCP,443:31962/TCP,1024:31675/TCP 97m
Route HTTP traffic to multiple hostnames at the same IP address Jump to heading
This section describes how to implement routing for multiple hostnames using the ingress controller.
Because the ingress controller receives all ingress traffic at its IP address before relaying it to the appropriate service in the cluster, you can define multiple hostnames in your Ingress resources to route traffic for various applications.
To define more than one hostname in an Ingress resource:
-
On your DNS server, creat an A or CNAME record that maps the hostnames to your Kubernetes cluster.
-
In the Ingress resource, prepare the
rules
section by creating a separate rule for each hostname. In the example below, we specify that requests formusic.example.com
will go tomusic-service
, while requests forbooks.example.com
will go tobooks-service
:example-ingress.yamlyamlapiVersion: networking.k8s.io/v1kind: Ingressmetadata:name: example-ingressspec:ingressClassName: haproxyrules:- host: "music.example.com"http:paths:- path: /pathType: Prefixbackend:service:name: music-serviceport:number: 8080- host: "books.example.com"http:paths:- path: /pathType: Prefixbackend:service:name: books-serviceport:number: 8080example-ingress.yamlyamlapiVersion: networking.k8s.io/v1kind: Ingressmetadata:name: example-ingressspec:ingressClassName: haproxyrules:- host: "music.example.com"http:paths:- path: /pathType: Prefixbackend:service:name: music-serviceport:number: 8080- host: "books.example.com"http:paths:- path: /pathType: Prefixbackend:service:name: books-serviceport:number: 8080 -
Deploy it with
kubectl
:nixkubectl apply -f example-ingress.yamlnixkubectl apply -f example-ingress.yaml -
Optional: Add another rule that does not specify a
host
field. This rule would create a fallback that would handle all of the HTTP requests that have a hostname that does not match the other rules. For example:example-ingress.yamlyaml- host:http:paths:- path: "/"pathType: Prefixbackend:service:name: fallback-serviceport:number: 8080example-ingress.yamlyaml- host:http:paths:- path: "/"pathType: Prefixbackend:service:name: fallback-serviceport:number: 8080
Route HTTP traffic based on the requested URL path Jump to heading
In this section, you’ll learn how to direct traffic based on the URL path the client requests. For example, if they request example.com/music
, you could route them to a service named music-service
. You can combine this technique with routing by hostname.
To route traffic by URL path:
-
Create an Ingress resource and include both a
path
field that sets the target URL path and apathType
field set to Prefix. In the example below, we route any request with a path beginning with/music
tomusic-service
. This applies to paths like/music/playlists/1
, for instance.example-ingress.yamlyamlapiVersion: networking.k8s.io/v1kind: Ingressmetadata:name: example-ingressspec:ingressClassName: haproxyrules:- http:paths:- path: /musicpathType: Prefixbackend:service:name: music-serviceport:number: 8080example-ingress.yamlyamlapiVersion: networking.k8s.io/v1kind: Ingressmetadata:name: example-ingressspec:ingressClassName: haproxyrules:- http:paths:- path: /musicpathType: Prefixbackend:service:name: music-serviceport:number: 8080 -
Optional: Rewrite the request’s path to remove the prefix. In many cases, you will receive HTTP requests at a prefix path, such as
/music
, but you will want to strip that off of the URL before the backend application processes it. To do so, set thepath-rewrite
annotation to a regular expression. Using the example below, a request for/music/playlists/1
would be rewritten to/playlists/1
:example-ingress.yamlyamlapiVersion: networking.k8s.io/v1kind: Ingressmetadata:name: example-ingressannotations:haproxy.org/path-rewrite: /music/(.*) /\1spec:ingressClassName: haproxyrules:- http:paths:- path: /musicpathType: Prefixbackend:service:name: music-serviceport:number: 8080example-ingress.yamlyamlapiVersion: networking.k8s.io/v1kind: Ingressmetadata:name: example-ingressannotations:haproxy.org/path-rewrite: /music/(.*) /\1spec:ingressClassName: haproxyrules:- http:paths:- path: /musicpathType: Prefixbackend:service:name: music-serviceport:number: 8080 -
Deploy this to your Kubernetes cluster using
kubectl
.nixkubectl apply -f example-ingress.yamlnixkubectl apply -f example-ingress.yaml -
If you deployed the ingress controller service using a NodePort, then you can access the example service at the NodePort HTTP port. For example,
http://example.com:30000/music
. To find which NodePort port has been assigned, view the service’s status:nixkubectl get service haproxy-kubernetes-ingress --namespace haproxy-controllernixkubectl get service haproxy-kubernetes-ingress --namespace haproxy-controllerPort 80 has been mapped to NodePort 30000:
outputtextNAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGEhaproxy-kubernetes-ingress NodePort 10.101.116.157 <none> 80:30000/TCP,443:31962/TCP,1024:31675/TCP 97moutputtextNAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGEhaproxy-kubernetes-ingress NodePort 10.101.116.157 <none> 80:30000/TCP,443:31962/TCP,1024:31675/TCP 97m
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