# Introduction to NGINX Ingress Controller

## Create a kubernetes cluster

In this guide we we''ll need a Kubernetes cluster for testing. Let's create one using [kind](https://kind.sigs.k8s.io/) </br>

```
kind create cluster --name nginx-ingress --image kindest/node:v1.23.5
```

See cluster up and running:

```
kubectl get nodes
NAME                  STATUS   ROLES                  AGE     VERSION
nginx-ingress-control-plane   Ready    control-plane,master   2m12s   v1.23.5
```

## Run a container to work in

### run Alpine Linux: 
```
docker run -it --rm -v ${HOME}:/root/ -v ${PWD}:/work -w /work --net host alpine sh
```

### install some tools

```
# install curl 
apk add --no-cache curl

# install kubectl 
curl -LO https://storage.googleapis.com/kubernetes-release/release/`curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt`/bin/linux/amd64/kubectl
chmod +x ./kubectl
mv ./kubectl /usr/local/bin/kubectl

# install helm 

curl -o /tmp/helm.tar.gz -LO https://get.helm.sh/helm-v3.10.1-linux-amd64.tar.gz
tar -C /tmp/ -zxvf /tmp/helm.tar.gz
mv /tmp/linux-amd64/helm /usr/local/bin/helm
chmod +x /usr/local/bin/helm

```

### test cluster access:
```
/work # kubectl get nodes
NAME                    STATUS   ROLES    AGE   VERSION
nginx-ingress-control-plane   Ready    control-plane,master   3m26s   v1.23.5
```

## NGINX Ingress Controller 

We'll start with the documentation as always </br>
You can find the [Kubernetes NGINX documentation here](https://kubernetes.github.io/ingress-nginx/) </br>

First thing we do is check the compatibility matrix to ensure we are deploying a compatible version of NGINX Ingress on our Kubernetes cluster </br>

The Documentation also has a link to the [GitHub Repo](https://github.com/kubernetes/ingress-nginx/) which has a compatibility matrix </br>

### Get the installation YAML

The controller ships as a `helm` chart, so we can grab version `v1.5.1` as per the compatibility
matrix. </br>

From our container we can do this:

```
helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx
helm search repo ingress-nginx --versions
```

From the app version we select the version that matches the compatibility matrix. </br>

```
NAME                            CHART VERSION   APP VERSION     DESCRIPTION
ingress-nginx/ingress-nginx     4.4.0           1.5.1           Ingress controller for Kubernetes using NGINX a...
```

Now we can use `helm` to install the chart directly if we want. </br>
Or we can use `helm` to grab the manifest and explore its content. </br>
We can also add that manifest to our git repo if we are using a GitOps workflow to deploy it. </br>

```
CHART_VERSION="4.4.0"
APP_VERSION="1.5.1"

mkdir ./kubernetes/ingress/controller/nginx/manifests/

helm template ingress-nginx ingress-nginx \
--repo https://kubernetes.github.io/ingress-nginx \
--version ${CHART_VERSION} \
--namespace ingress-nginx \
> ./kubernetes/ingress/controller/nginx/manifests/nginx-ingress.${APP_VERSION}.yaml
```

### Deploy the Ingress controller 

```
kubectl create namespace ingress-nginx
kubectl apply -f ./kubernetes/ingress/controller/nginx/manifests/nginx-ingress.${APP_VERSION}.yaml
```


### Check the installation

```
kubectl -n ingress-nginx get pods
```
The traffic for our cluster will come in over the Ingress service </br>
Note that we dont have load balancer capability in `kind` by default, so our `LoadBalancer` is pending:

```
kubectl -n ingress-nginx get svc
NAME                                 TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)                      AGE
ingress-nginx-controller             LoadBalancer   10.96.130.21    <pending>     80:31011/TCP,443:31772/TCP   26m
ingress-nginx-controller-admission   ClusterIP      10.96.125.210   <none>        443/TCP                      26m
```

For testing purposes, we will simply setup `port-forward`ing </br>
If you are running in the cloud, you will get a real IP address. </br>

```
kubectl -n ingress-nginx port-forward svc/ingress-nginx-controller 443
```

We can reach our controller on [https://localhost/](https://localhost/)

## Features

* Routing DOMAIN
* SSL terminating & passthrough

* routing URL

customization (configmap)

* location snippet
* log formating