Add TCP/UDP ingress tutorial

site/content/en/docs/Tutorials/nginx_tcp_udp_ingress.md

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+---
+title: "Ingress nginx for TCP and UDP services"
+linkTitle: "Ingress nginx for TCP and UDP services"
+weight: 1
+date: 2019-08-15
+description: >
+  How to set up a minikube ingress for TCP and UDP services
+---
+
+## Overview
+
+
+The Minikube [ingress addon](https://github.com/kubernetes/minikube/tree/master/deploy/addons/ingress) enables developers 
+to route traffic from their Host OS (Laptop, Desktop, etc) to a kubernetes service running inside their minikube cluster.
+The ingress addon uses the [ingress nginx](https://github.com/kubernetes/ingress-nginx) controller which by default
+is only configured to listen on ports 80 and 443. TCP and UDP services listening on other ports can be enabled.
+
+## Prerequisites
+
+- Latest minikube binary and ISO
+- Telnet command line tool
+- Kubectl command line tool
+- A text editor
+
+## Configuring TCP and UDP services with the nginx ingress controller
+
+### Enable the ingress addon 
+
+Enable the minikube ingress addon with the following command: 
+
+```shell
+minikube addons enable ingress
+```
+
+### Update the TCP and/or UDP services configmaps
+
+Borrowing from the tutorial on [configuring TCP and UDP services with the ingress nginx controller](https://kubernetes.github.io/ingress-nginx/user-guide/exposing-tcp-udp-services/)
+we will need to edit the configmap which is installed by default when enabling the minikube ingress addon 
+
+There are 2 configmaps 1 for TCP services and 1 for UDP services. By default they look like this: 
+
+```yaml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: tcp-services
+  namespace: ingress-nginx
+```
+
+```yaml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: udp-services
+  namespace: ingress-nginx
+```
+
+Since these configmaps are centralized and may contain configurations it is best if we only patch them rather than completely overwrite them. 
+
+Lets use this redis deployment as an example
+
+`redis-deployment.yaml`
+```yaml
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: redis-deployment
+  namespace: default
+  labels:
+    app: redis
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: redis
+  template:
+    metadata:
+      labels:
+        app: redis
+    spec:
+      containers:
+      - image: redis
+        imagePullPolicy: Always
+        name: redis
+        ports:
+        - containerPort: 6379
+          protocol: TCP
+```
+
+Create a file `redis-deployment.yaml` and paste the contents above. Then install the redis deployment with the following command:
+```shell
+kubectl apply -f redis-deployment.yaml
+```
+
+`redis-service.yaml`
+```yaml
+apiVersion: v1
+kind: Service
+metadata:
+  name: redis-service
+  namespace: default
+spec:
+  selector:
+    app: redis
+  type: ClusterIP
+  ports:
+    - name: tcp-port
+      port: 6379
+      targetPort: 6379
+      protocol: TCP
+```
+
+Create a file `redis-service.yaml` and paste the contents above. Then install the redis deployment with the following command:
+```shell
+kubectl apply -f redis-service.yaml
+```
+
+To add a TCP service to the ingress you can run the following command
+
+```shell
+kubectl patch configmap tcp-services -n kube-system --patch '{"data":{"6379":"default/redis-service:6379"}}'
+```
+
+Where 
+- 6379 : the port your service should listen to from outside the minikube virtual machine
+- default : the namespace that your service is installed in
+- redis-service : the name of the service
+
+We can verify that our resource was patched with the following command: 
+
+```shell
+kubectl get configmap tcp-services -n kube-system -o yaml
+```
+
+We should see something like this: 
+
+```yaml
+apiVersion: v1
+data:
+  "6379": default/redis-service:6379
+kind: ConfigMap
+metadata:
+  creationTimestamp: "2019-10-01T16:19:57Z"
+  labels:
+    addonmanager.kubernetes.io/mode: EnsureExists
+  name: tcp-services
+  namespace: kube-system
+  resourceVersion: "2857"
+  selfLink: /api/v1/namespaces/kube-system/configmaps/tcp-services
+  uid: 4f7fac22-e467-11e9-b543-080027057910
+```
+
+The only value you need to validate is that there is a value under the `data` property that looks like this: 
+
+```yaml
+  "6379": default/redis-service:6379
+```
+
+### Patch the ingress-nginx-controller
+
+There is one final steps that must be done in order to obtain connectivity from the outside cluster.
+We need to patch our nginx controller so that it is listening on port 6379 and can route traffic to your service
+
+`nginx-ingress-controller-patch.yaml`
+```yaml
+spec:
+  template:
+    spec:
+      containers:
+      - name: nginx-ingress-controller
+        ports:
+         - containerPort: 6379
+           hostPort: 6379
+```
+
+Create a file called `nginx-ingress-controller-patch.yaml` and paste the contents above
+
+Next apply the changes with the following command:
+```shell
+kubectl patch deployment nginx-ingress-controller --patch "$(cat nginx-ingress-controller-patch.yaml)" -n kube-system
+```
+
+### Test your connection
+
+Test that you can reach your service with telnet via the following command
+
+```shell
+telnet $(minikube ip) 6379
+```
+
+You should see the following output
+```text
+Trying 192.168.99.179...
+Connected to 192.168.99.179.
+Escape character is '^]'
+```
+
+To exit telnet enter the `Ctrl` key and `]` at the same time. Then type `quit` and press enter
+
+If you were not able to connect please review your steps above. 
+
+## Review
+
+In the above example we did the following
+- Created a redis deployment and service in the `default` namespace
+- Patched the `tcp-services` configmap in the `kube-system` namespace
+- Patched the `nginx-ingress-controller` deployment in the `kube-system` namespace
+- Forced the `nginx-ingress-controller` to redeploy all of its pods
+- Connected to our service from the host via port 6379
+
+You can apply the same steps that were applied to `tcp-services` to the `udp-services` configmap as well if you have a 
+service that uses UDP and/or TCP
+