Kubernetes NGINX-INGRESS Do I need an NGINX Service running? - nginx

Question

I am attempting to create an NGINX-INGRESS (locally at first, then to be deployed to AWS behind a load-balancer). However I am new to Kubernetes, and I understand the Ingress model for NGINX- the configurations are confusing me as to weather I should be deploying an NGINX-INGRESS Service, Ingress or Both
I am working with multiple Flask-Apps I would like to have routed by path (/users, /content, etc.) My services are named user-service on port: 8000 (their container port is 8000 as well)
In this example an Ingress is defined. However, when I apply an ingress (in the same Namespace as my Flask there is no response from http://localhost
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: ingress-name
namespace: my-namespace
spec:
rules:
- http:
paths:
- path: /users
backend:
serviceName: users-service
servicePort: 8000
- path: /content
backend:
serviceName: content-service
servicePort: 8000
Furthermore, looking at the nginx-ingress "Deployment" docs, under Docker for Mac (which I assume I can use as I am using Docker on a MacOS) they define a Service like so:
kind: Service
apiVersion: v1
metadata:
name: ingress-nginx
namespace: ingress-nginx
labels:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
spec:
externalTrafficPolicy: Local
type: LoadBalancer
selector:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
ports:
- name: http
port: 80
protocol: TCP
targetPort: http
- name: https
port: 443
protocol: TCP
targetPort: https
---
This seems to function for me (When I open "localhost" I get Nginx "not found", but it is a service in a different namespace then my apps- and there is no association between the port 80/443 and my service-ports.
For reference here is one of my deployment/service definitions:
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: users-service
labels:
app: users-service
namespace: example
spec:
replicas: 1
selector:
matchLabels:
app: users-service
template:
metadata:
labels:
app: users-service
spec:
containers:
- name: users-service
image: users-service:latest
imagePullPolicy: Never
ports:
- containerPort: 8000
---
kind: Service
apiVersion: v1
metadata:
name: users-service
spec:
selector:
app: users-service
ports:
- protocol: TCP
port: 8000
Update
I followed a video for setting up an NGINX-Controller+Ingress, here the results, entering "localhost/users" does not work,
describe-ingress:
(base) MacBook-Pro-2018-i9:microservices jordanbaucke$ kubectl describe ingress users-ingress
Name: users-ingress
Namespace: default
Address:
Default backend: default-http-backend:80 (<error: endpoints "default-http-backend" not found>)
Rules:
Host Path Backends
---- ---- --------
*
/users users-service:8000 (10.1.0.75:8000)
Annotations: Events: <none>
users-service:
(base) MacBook-Pro-2018-i9:microservices jordanbaucke$ kubectl describe svc users-service
Name: users-service
Namespace: default
Labels: <none>
Annotations: Selector: app=users-service
Type: ClusterIP
IP: 10.100.213.229
Port: <unset> 8000/TCP
TargetPort: 8000/TCP
Endpoints: 10.1.0.75:8000
Session Affinity: None
Events: <none>
nginx-ingress
(base) MacBook-Pro-2018-i9:microservices jordanbaucke$ kubectl describe svc nginx-ingress
Name: nginx-ingress
Namespace: default
Labels: <none>
Annotations: Selector: name=nginx-ingress
Type: NodePort
IP: 10.106.167.181
LoadBalancer Ingress: localhost
Port: http 80/TCP
TargetPort: 80/TCP
NodePort: http 32710/TCP
Endpoints: 10.1.0.74:80
Port: https 443/TCP
TargetPort: 443/TCP
NodePort: https 32240/TCP
Endpoints: 10.1.0.74:443
Session Affinity: None
External Traffic Policy: Cluster
Events: <none>
Now when I try to enter the combination of NodeIP:NodePort/users, it does not connect?
From inside my nginx-ingress pod, calling:
curl 10.1.0.75:8000 or curl 10.100.213.229:8000 returns results.

Answer 1

For nginx or any other ingress to work properly:
Nginx ingress controller need to deployed on the cluster
A LoadBalancer or NodePort type service need to be created to expose nginx ingress controller via port 80 and 443 in the same namespace where nginx ingress controller is deployed.LoadBalancer works in supported public cloud(AWS etc). NodePort works if running locally.
ClusterIP type service need to be created for workload pods in the namespace where workload pods are deployed.
Workload Pods will be exposed via nginx ingress and you need to create ingress resource in the same namespace as of the clusterIP service of your workload Pods.
You will use either the LoadBalancer(in case nginx ingress controller was exposed via LoadBalancer) or NodeIP:NodePort(in case Nginx ingress controller was exposed via NodePort) to access your workload Pods.
So in this case since docker desktop is being used Loadbalancer type service(ingress-nginx) to expose nginx ingress controller will not work. This needs to be of NodePort type. Once done workload pods can be accessed via NodeIP:NodePort/users and NodeIP:NodePort/content. NodeIP:NodePort should give nginx homepage as well.