Ingress Controller
In order for ingress controller to operate we must have an ingress controller running. With the help of ingress we can expose multiple services using a single endpoint or single load balancer.
For this we need to expose our deployments without loadbalancer as a type using the below command:
kubectl expose deployment <deployment-name> --port <port no.>
Once we are done with the above command it will expose our deployments and will create a service for our deployment.
After that we need to deploy nginx ingress controller which is a ingress controller provided by kubernetes. Now suppose we are having three services that are need to be exposed or need to be accessed from outside of the cluster, we just simply need to pass the path along with the service name and port number which needs to be exposed. Later on we can access those particular services by hitting the endpoint of our ingress controller along with the path.
We will deploy the ingress controller using helm https://salesforcedrillers.com/learn-devops/helm/
First of all we need to add the kubernetes ingress controller stable chart repository to our helm repositories by using the below command:
helm repo add stable https://kubernetes-charts.storage.googleapis.com/
Once added then execute the below command to deploy the helm chart
helm install nginx-ingress stable/nginx-ingress
After this it will create two pods of nginx-controller along with two services
Then we need to create two or more deployments so that we can expose them with single ingress endpoint. You can use the below yamls for creating deployments
NGINX DEPLOYMENT MAIN
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
run: nginx
name: nginx-deploy-main
spec:
replicas: 1
selector:
matchLabels:
run: nginx-main
template:
metadata:
labels:
run: nginx-main
spec:
containers:
- image: nginx
name: nginx
NGINX DEPLOYMENT GREEN
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
run: nginx
name: nginx-deploy-green
spec:
replicas: 1
selector:
matchLabels:
run: nginx-green
template:
metadata:
labels:
run: nginx-green
spec:
volumes:
- name: webdata
emptyDir: {}
initContainers:
- name: web-content
image: busybox
volumeMounts:
- name: webdata
mountPath: "/webdata"
command: ["/bin/sh", "-c", 'echo "<h1>I am <font color=green>GREEN</font></h1>" > /webdata/index.html']
containers:
- image: nginx
name: nginx
volumeMounts:
- name: webdata
mountPath: "/usr/share/nginx/html"
NGINX DEPLOYMENT BLUE
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
run: nginx
name: nginx-deploy-blue
spec:
replicas: 1
selector:
matchLabels:
run: nginx-blue
template:
metadata:
labels:
run: nginx-blue
spec:
volumes:
- name: webdata
emptyDir: {}
initContainers:
- name: web-content
image: busybox
volumeMounts:
- name: webdata
mountPath: "/webdata"
command: ["/bin/sh", "-c", 'echo "<h1>I am <font color=blue>BLUE</font></h1>" > /webdata/index.html']
containers:
- image: nginx
name: nginx
volumeMounts:
- name: webdata
mountPath: "/usr/share/nginx/html"
Now simply do kubectl apply -f then it will create 3 deployments based on the above yamls and then further expose the deployments with kubectl expose command that has been shown above in this section.
Now finally we will deploy our ingress.yaml with the help of yaml stated below:
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/rewrite-target: /
name: salesforcedrillers-ingress
spec:
rules:
- host: demo.salesforcedrillers.com
http:
paths:
- path: /
backend:
serviceName: nginx-deploy-main
servicePort: 80
- path: /blue
backend:
serviceName: nginx-deploy-blue
servicePort: 80
- path: /green
backend:
serviceName: nginx-deploy-green
servicePort: 80
NOTE:- REMEMBER TO REPLACE THE INGRESS HOST NAME WITH YOUR INGRESS ENDPOINT, AND IF YOU ARE USING MINIKUBE THEN YOU NEED TO DO THE ENTRY IN YOUR HOSTS FILE
After applying when you will simply hit the host name you will be redirected to the nginx-deploy-main service, when you will hit the endpoint with /blue you will be redirected to nginx-deploy-blue service and when you will hit the endpoint with /green you will be redirected to nginx-deploy-green service.