Nginx Ingress Controller Server Snippets Example

1st-deployment-svc-ingress.yaml

# This configuration is an example of how to get an Ingress to respond directly
# to a path, without routing to a service. This setup is being used on a DOKS
# service, with Nginx Ingress Controller installed and a Load Balancer in place.
# Those pieces can be setup easily with a 1-click install in the DO Marketplace:
# https://marketplace.digitalocean.com/apps/nginx-ingress-controller. I then
# grabbed the IP adress of the LB and pointed an A record at it. With that in
# place, this YAML can be applied with: 
#     kubectl apply -f ingress-nginx-server-snippets-example.yaml

# Once this is applied, you can test it with:
#    curl http://<HOSTNAME>/anything # Will respond with echo from the container
#    curl http://<HOSTNAME>/direct   # Will respond with direct response from the Ingress

# Create a dummy deployment of mendhak/http-https-echo:26 to attach ingress to
apiVersion: apps/v1
kind: Deployment
metadata:
  name: http-echo
  namespace: default
spec:
  replicas: 1
  selector:
    matchLabels:
      app: http-echo
  template:
    metadata:
      labels:
        app: http-echo
    spec:
      containers:
      - name: http-echo
        image: mendhak/http-https-echo:26
        ports:
        - name: http
          containerPort: 8080
---
# Create a service for the above deployment
apiVersion: v1
kind: Service
metadata:
  name: http-echo-svc
  namespace: default
spec:
  selector:
    app: http-echo
  ports:
  - protocol: TCP
    port: 80
    targetPort: 8080
---
# Create an ingress that will route to the above service, but directly respond to /direct
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-direct
  namespace: default
  annotations:
    nginx.ingress.kubernetes.io/server-snippet: |
      location ~ .* {
        return 200 'Hello, directly from the Ingress!';
        access_log off;
      }
spec:
  rules:
    - host: ingress.tjl2.uk
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: http-echo-svc
                port:
                  number: 80
  ingressClassName: nginx 

2nd-deployment-svc-ingress.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: http-echo1
  namespace: default
spec:
  replicas: 1
  selector:
    matchLabels:
      app: http-echo1
  template:
    metadata:
      labels:
        app: http-echo1
    spec:
      containers:
      - name: http-echo1
        image: mendhak/http-https-echo:26
        ports:
        - name: http
          containerPort: 8080
---
# Create a service for the above deployment
apiVersion: v1
kind: Service
metadata:
  name: http-echo1-svc
  namespace: default
spec:
  selector:
    app: http-echo1
  ports:
  - protocol: TCP
    port: 80
    targetPort: 8080
---
# Create an ingress that will route to the above service, but directly respond to /direct
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: http-echo1-ingress
  namespace: default
spec:
  rules:
    - host: http-echo.tjl2.uk
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: http-echo1-svc
                port:
                  number: 80
  ingressClassName: nginx

With the above configurations in place, here's how everything behaves:

Requests to http-echo.tjl2.uk respond with a response from the http-echo deployment

curl http://http-echo.tjl2.uk/blah
{
  "path": "/blah",
  "headers": {
    "host": "http-echo.tjl2.uk",
    "x-request-id": "a57a29506e088896a388ff10c54108ac",
    "x-real-ip": "10.244.0.115",
    "x-forwarded-for": "10.244.0.115",
    "x-forwarded-host": "http-echo.tjl2.uk",
    "x-forwarded-port": "80",
    "x-forwarded-proto": "http",
    "x-forwarded-scheme": "http",
    "x-scheme": "http",
    "user-agent": "curl/8.1.2",
    "accept": "*/*"
  },
  "method": "GET",
  "body": "",
  "fresh": false,
  "hostname": "http-echo.tjl2.uk",
  "ip": "10.244.0.115",
  "ips": [
    "10.244.0.115"
  ],
  "protocol": "http",
  "query": {},
  "subdomains": [
    "http-echo"
  ],
  "xhr": false,
  "os": {
    "hostname": "http-echo1-6447d55685-zwxsl"
  },
  "connection": {}
}

Requests to ingress.tjl2.uk respond with the ingress server-snippet

curl http://ingress.tjl2.uk/blah
Hello, directly from the Ingress!