We'll go through a step by step guide to implement Canary Releases using Ingress Controller!
ingress-nginx
ingress-nginx Ingress controller for Kubernetes using NGINX as a reverse proxy and load balancer
To use, add ingressClassName: nginx spec field or the kubernetes.io/ingress.class: nginx annotation to your Ingress resources.
Requirements
Kubernetes: >=1.20.0-0
Get repo Info
helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx
helm repo update
Install chart
Important: only helm3 is supported
kubectl create ns nginx
helm install --set controller.service.type=NodePort --set controller.admissionWebhooks.enabled=false --namespace nginx [RELEASE_NAME] ingress-nginx/ingress-nginx
Canary
Ingress Nginx has the ability to handle canary routing by setting specific annotations, the following is an example of how to configure a canary deployment with weighted canary routing.
For advanced monitoring of your Ingress resources, consider using the Ingress Monitor Controller. It integrates seamlessly with your Kubernetes environment, providing real-time monitoring of Ingress endpoints.
Create namespace for Canary Demo
kubectl create ns canary-demo
Create your main deployment and service
This is the main deployment of your application with the service that will be used to route to it
echo "
---
# Deployment
apiVersion: apps/v1
kind: Deployment
metadata:
name: production
namespace: canary-demo
labels:
app: production
spec:
replicas: 1
selector:
matchLabels:
app: production
template:
metadata:
labels:
app: production
spec:
containers:
- name: production
image: registry.k8s.io/ingress-nginx/e2e-test-echo@sha256:6fc5aa2994c86575975bb20a5203651207029a0d28e3f491d8a127d08baadab4
ports:
- containerPort: 80
env:
- name: NODE_NAME
valueFrom:
fieldRef:
fieldPath: spec.nodeName
- name: POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
- name: POD_IP
valueFrom:
fieldRef:
fieldPath: status.podIP
---
# Service
apiVersion: v1
kind: Service
metadata:
name: production
namespace: canary-demo
labels:
app: production
spec:
ports:
- port: 80
targetPort: 80
protocol: TCP
name: http
selector:
app: production
" | kubectl apply -f -
Create the canary deployment and service
This is the canary deployment that will take a weighted amount of requests instead of the main deployment
echo "
---
# Deployment
apiVersion: apps/v1
kind: Deployment
metadata:
name: canary
namespace: canary-demo
labels:
app: canary
spec:
replicas: 1
selector:
matchLabels:
app: canary
template:
metadata:
labels:
app: canary
spec:
containers:
- name: canary
image: registry.k8s.io/ingress-nginx/e2e-test-echo@sha256:6fc5aa2994c86575975bb20a5203651207029a0d28e3f491d8a127d08baadab4
ports:
- containerPort: 80
env:
- name: NODE_NAME
valueFrom:
fieldRef:
fieldPath: spec.nodeName
- name: POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
- name: POD_IP
valueFrom:
fieldRef:
fieldPath: status.podIP
---
# Service
apiVersion: v1
kind: Service
metadata:
name: canary
namespace: canary-demo
labels:
app: canary
spec:
ports:
- port: 80
targetPort: 80
protocol: TCP
name: http
selector:
app: canary
" | kubectl apply -f -
Create Ingress pointing to your main deployment
Next you will need to expose your main deployment with an ingress resource, note there are no canary specific annotations on this ingress
echo "
---
# Ingress
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: production
namespace: canary-demo
annotations:
spec:
ingressClassName: nginx
rules:
- host: echo.prod.mydomain.com
http:
paths:
- pathType: Prefix
path: /
backend:
service:
name: production
port:
number: 80
" | kubectl apply -f -
Create Ingress pointing to your canary deployment
You will then create an Ingress that has the canary specific configuration, please pay special notice of the following:
The host name is identical to the main ingress host name
The
nginx.ingress.kubernetes.io/canary: "true"
annotation is required and defines this as a canary annotation (if you do not have this the Ingresses will clash)
The
nginx.ingress.kubernetes.io/canary-weight: "50"
annotation dictates the weight of the routing, in this case there is a "50%" chance a request will hit the canary deployment over the main deployment
echo "
---
# Ingress
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: canary
namespace: canary-demo
annotations:
nginx.ingress.kubernetes.io/canary: "true"
nginx.ingress.kubernetes.io/canary-weight: "50"
spec:
ingressClassName: nginx
rules:
- host: echo.prod.mydomain.com
http:
paths:
- pathType: Prefix
path: /
backend:
service:
name: canary
port:
number: 80
" | kubectl apply -f -
Testing your setup
You can use the following command to test your setup (replacing INGRESS_CONTROLLER_IP with your ingresse controllers IP Address)
for i in $(seq 1 100); do curl -s echo.prod.mydomain.com:$INGRESS_CONTROLLER_PORT | grep "Hostname" ; done
You will get the following output showing that your canary setup is working as expected:
Hostname: production-5c5f65d859-phqzc
Hostname: canary-6697778457-zkfjf
Hostname: canary-6697778457-zkfjf
Hostname: production-5c5f65d859-phqzc
Hostname: canary-6697778457-zkfjf
Hostname: production-5c5f65d859-phqzc
Hostname: production-5c5f65d859-phqzc
Hostname: production-5c5f65d859-phqzc
Hostname: canary-6697778457-zkfjf
Hostname: production-5c5f65d859-phqzc
Let us know if you found this useful or in case if you have any tips!
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