#Creating Ingresses

Ingress rules (Kubernetes Ingress) expose HTTP/HTTPS routes from outside the cluster to internal routing (Kubernetes Service), enabling control of external access to computing components.

Create an Ingress to manage the external HTTP/HTTPS access to a Service.

#Implementation Method

Ingress rules depend on the implementation of the Ingress Controller, which is responsible for listening to changes in Ingress and Service. After a new Ingress rule is created, a forwarding rule matching the Ingress rule is automatically generated within the Ingress Controller. When the Ingress Controller receives a request, it matches the forwarding rule from the Ingress rule and distributes the traffic to the specified internal routes, as shown in the diagram below.

#Quick Start

Next, we will use the community version of Ingress-NGINX to demonstrate how to access your own application using the NGINX controller.

1. deploy Ingress-NGINX controller.

   kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.12.2/deploy/static/provider/cloud/deploy.yaml

   The following resources are automatically created after using this command:

   Kind	Name	Description
   Namespace	ingress-nginx	Resources for Isolating Controllers
   ServiceAccount	ingress-nginx	Service account for the controller
   ClusterRole	ingress-nginx	Cluster-wide permissions
   ClusterRoleBinding	ingress-nginx	Bind ClusterRole to SA
   ConfigMap	ingress-nginx-controller	Configure controller behaviour (e.g. logging levels, proxy timeout, etc.)
   ValidatingWebhookConfig	ingress-nginx-admission	Webhook to verify Ingress configuration legitimacy (optional)
   Service (TCP/UDP)	ingress-nginx-controller	The type defaults to LoadBalancer and can be changed to NodePort.
   Deployment	ingress-nginx-controller
   Pod	ingress-nginx-controller-xxx
   Role/RoleBinding	admission 相关	Support for webhook
   Job	ingress-nginx-admission-create	webhook Registration

   If you want to change the default registry address, you can use curl to download the YAML file, change it, and then apply the YAML file.

   curl -O https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.12.2/deploy/static/provider/cloud/deploy.yaml

   Waiting for the ingress-nginx-controller-xxx Pod to run

2. Local testing

   • Creating a simple web server and the associated service:

     kubectl create deployment demo --image=nginx --port=80
     kubectl expose deployment demo

   • Creating an ingress resource. This example uses a host that maps to localhost:

     kubectl create ingress demo-localhost --class=nginx \
       --rule="demo.local/*=demo:80"

   • Forward a local port to the ingress controller:

     kubectl port-forward --namespace=ingress-nginx service/ingress-nginx-controller 8080:80

   • Accessing your deployment using curl:

     curl --resolve demo.local:8080:127.0.0.1 http://demo.local:8080

     Note: This parameter temporarily resolves the domain name demo.local to IP 127.0.0.1 and is used on port 8080. When you visit http://demo.local:8080, you are actually visiting http://127.0.0.1:8080. On the other hand, you should configure hosts:

     echo "127.0.0.1 demo.local" | sudo tee -a /etc/hosts

     Final you should see a HTML response containing text like "Welcome to nginx!".

     Then you can access website http://demo.local:8080/.

   INFO

   ingress-nginx-controller default type is LoadBalancer, If EXTERNAL-IP field shows pending, this means that your Kubernetes cluster wasn't able to provision the load balancer.

   If you're integrating with a provider that supports specifying the load balancer IP address(es) for a Service via a (provider specific) annotations, you should switch to doing that.

3. Online testing

   When your ingress-nginx-controller (Service of LoadBalancer type) exists an EXTERNAL-IP, Then you can create an ingress resource. The following example assumes that you have set up a DNS record for www.developer.io:

   kubectl create ingress demo --class=nginx \
     --rule="www.developer.io/*=demo:80"

   You can access http://www.developer.io to see the same output.

#Prerequisites

• There must be an available Service in the current namespace.

• Please confirm with the administrator that a usable domain name has been allocated for the project associated with the current namespace.

• To access the domain via HTTPS, you need to first save the HTTPS certificate as a TLS secret.

#Example Ingress:

# nginx-ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: nginx-ingress
  namespace: k-1
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  ingressClassName: nginx
  rules:
    - host: demo.local
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: nginx-service
                port:
                  number: 80

#Creating a Ingress by using the web console

1. Access the Container Platform.

2. In the left navigation bar, click Network > Ingress.

3. Click Create Ingress.

4. Reference the instructions below to configure certain parameters.

   Parameter	Description
   Ingress Class	Ingresses can be implemented by different controllers with different IngressClass name. If multiple ingress controllers are available on the platform, the user can select which one to use with this option.
   Domain Name	Hosts can be precise matches (for example foo.bar.com) or a wildcard (for example *.foo.com). The domain names available are allocated by platform administrator.
   Certificates	TLS secret or Certificates allocated by platform administrator.
   Match Type and Path	Prefix: Matches path prefixes, e.g., /abcd can match /abcd/efg or /abcde. Exact: Matches exact paths, e.g., /abcd. Implementation specific: If you are using a custom Ingress controller to manage the Ingress rules, you may choose to have the controller decide.
   Service	External traffic will be forwarded to this Service.
   Service Port	Specify which Service port the traffic will be forwarded to.

5. Click Create.

#Creating a Ingress by using the CLI

kubectl apply -f nginx-ingress.yaml