pascalandy · December 11, 2019 20:15 · Nov 6, 2019 · Nov 6, 2019 · Oct 4, 2019 · Oct 4, 2019
diff --git a/whoami-deployment.yml b/whoami-deployment.yml
@@ -1,11 +1,14 @@
 ---
 kind: Deployment
-apiVersion: apps/v1 #extensions/v1beta1
+apiVersion: apps/v1
 metadata:
   name: whoami
   namespace: whoami
 spec:
   replicas: 2
+  selector:
+    matchLabels:
+      app: whoami
   template:
     metadata:
       labels:
@@ -14,4 +17,4 @@ spec:
       containers:
       - name: whoami
         image: containous/whoami
-        imagePullPolicy: Always
+        imagePullPolicy: Always
diff --git a/whoami-deployment.yml b/whoami-deployment.yml
@@ -1,6 +1,6 @@
 ---
 kind: Deployment
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1 #extensions/v1beta1
 metadata:
   name: whoami
   namespace: whoami

diff --git a/README.md b/README.md
@@ -164,3 +164,8 @@ whoami   localhost   172.30.0.2   80      7s
 ## Cleanup
 
 Destroy the cluster with `k3d delete` (check with `docker ps`).
+
+## Going Further
+
+- <https://medium.com/@geraldcroes/kubernetes-traefik-101-when-simplicity-matters-957eeede2cf8>
+- <https://kubernetes.io/docs/tutorials/kubernetes-basics/>
diff --git a/README.md b/README.md
@@ -160,3 +160,7 @@ whoami   localhost   172.30.0.2   80      7s
 
 - You can now open the URL <http://localhost:80> and access the web service.
   If you reload the page, you'll see the same "load balancing" behavior as earlier with `curl`.
+
+## Cleanup
+
+Destroy the cluster with `k3d delete` (check with `docker ps`).
diff --git a/README.md b/README.md
@@ -0,0 +1,162 @@
+# Kube 101
+
+## Requirements
+
+- Docker Engine 19.03+ (tested successfully with Docker4Mac or Docker Linux)
+- `k3d` binary installed on your PATH (<https://github.com/rancher/k3d>)
+- `kubectl` binary installed on your PATH (<https://kubernetes.io/docs/tasks/tools/install-kubectl/>)
+- A bash prompt
+
+## Create Kubernetes Cluster
+
+- Using the `k3d` command, create a Kubernetes cluster with the following properties:
+  - 1 master node and 3 worker nodes,
+  - ports 80 and 443 published on the `localhost` interface of your host machine,
+
+```bash
+k3d create --publish="80:80" --publish="443:443" --workers="3"
+```
+
+- 4 docker containers are now running: 1 for the master node and 3 for the worker nodes:
+
+```bash
+docker ps
+```
+
+## Configure `kubectl`
+
+- Use the configuration generated by `k3d` for `kubectl`,
+by following the instructions from `k3d` output:
+
+```bash
+export KUBECONFIG="$(k3d get-kubeconfig --name='k3s-default')"
+kubectl cluster-info
+```
+
+You should see the following output:
+
+```text
+
+Kubernetes master is running at https://localhost:6443
+CoreDNS is running at https://localhost:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
+
+To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
+```
+
+## Interact with Kubernetes API
+
+- Check the cluster topology:
+
+```bash
+kubectl get nodes
+# You should see 1 master and 3 workers
+```
+
+- Check the pods running, cluster wide:
+
+```bash
+$ kubectl get pod --all-namespaces
+
+NAMESPACE     NAME                         READY   STATUS      RESTARTS   AGE
+kube-system   coredns-b7464766c-mtj2k      1/1     Running     0          3m45s
+kube-system   helm-install-traefik-bw2tg   0/1     Completed   0          3m46s
+kube-system   svclb-traefik-9fknp          2/2     Running     0          3m27s
+kube-system   svclb-traefik-ppffn          2/2     Running     0          3m27s
+kube-system   svclb-traefik-vxdlk          2/2     Running     0          3m27s
+kube-system   svclb-traefik-z7wfh          2/2     Running     0          3m27s
+kube-system   traefik-56688c4464-r8ctk     1/1     Running     0          3m27s
+```
+
+- Open the URL <http://localhost>: you should see a `404 page not found` page. It means an HTTP server is answering in the cluster on port 80.
+
+## Deploy the Example Web Application
+
+- Create the namespace named `whoami`:
+
+```bash
+$ kubectl get namespaces
+NAME              STATUS   AGE
+default           Active   5m56s
+kube-node-lease   Active   5m56s
+kube-public       Active   5m56s
+kube-system       Active   5m56s
+# No "whoami" namespace
+
+$ kubectl apply -f ./whoami-namespace.yml
+namespace/whoami created
+
+$ kubectl get namespaces
+NAME              STATUS   AGE
+default           Active   6m46s
+kube-node-lease   Active   6m46s
+kube-public       Active   6m46s
+kube-system       Active   6m46s
+whoami            Active   14s
+# New "whoami" namespace
+```
+
+- Create the "deployment", which should create 2 pods (because 2 replicas).
+  The "whoami" container is a web application listening on its port `80`
+  which respond to HTTP `GET` requests by responding (body) the headers of the request:
+
+```bash
+$ kubectl get pod --namespace=whoami
+No resources found in whoami namespace.
+
+$ kubectl apply -f ./whoami-deployment.yml
+deployment.extensions/whoami created
+
+kubectl get pod --namespace=whoami
+NAME                      READY   STATUS    RESTARTS   AGE
+whoami-756586b9ff-h4vlq   1/1     Running   0          8s
+whoami-756586b9ff-j6sqg   1/1     Running   0          8s
+```
+
+- Expose + Load Balance the 2 replicated pod of the deployment by creating a new "service":
+
+```bash
+$ kubectl get service --namespace=whoami
+No resources found in whoami namespace.
+
+$ kubectl apply -f ./whoami-service.yml
+service/whoami created
+
+$ kubectl get service --namespace=whoami
+NAME     TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE
+whoami   ClusterIP   <IP>            <none>        80/TCP    13s
+```
+
+- Spawn a new pod in the same namespace, with an interactive shell
+  to request the "service" and see loadbalancing happening (look at `IP:` field on the response body):
+
+```bash
+kubectl run --tty -i --rm --image=alpine --namespace=whoami -- sh
+(...)
+/ # apk add --no-cache curl # Install curl
+(...)
+/ # curl http://<IP>:80 # Wher <IP> is the "cluster IP" of the service
+(...)
+/ # curl http://<IP>:80 # Wher <IP> is the "cluster IP" of the service
+(...)
+/ # exit
+(...)
+deployment.apps "sh" deleted
+```
+
+- Publish the "service" to outside the cluster by creating a new "Ingress",
+  that will be implemented by Traefik, the Ingress Controller of the cluster:
+
+```bash
+$ kubectl get ingress --namespace=whoami
+No resources found in whoami namespace.
+
+$ kubectl apply -f whoami-ingress.yml
+ingress.extensions/whoami created
+
+$ kubectl get ingress --namespace=whoami
+NAME     HOSTS       ADDRESS      PORTS   AGE
+whoami   localhost   172.30.0.2   80      7s
+```
+
+- You can now open the URL <http://localhost:80> and access the web service.
+  If you reload the page, you'll see the same "load balancing" behavior as earlier with `curl`.
diff --git a/whoami-deployment.yml b/whoami-deployment.yml
@@ -1,3 +1,4 @@
+---
 kind: Deployment
 apiVersion: extensions/v1beta1
 metadata:

diff --git a/whoami-ingress.yml b/whoami-ingress.yml
@@ -0,0 +1,19 @@
+---
+apiVersion: extensions/v1beta1
+kind: Ingress
+metadata:
+  name: whoami
+  namespace: whoami
+  labels:
+    app: whoami
+  annotations:
+    kubernetes.io/ingress.class: 'traefik'
+    traefik.frontend.passHostHeader: 'true'
+spec:
+  rules:
+  - host: localhost
+    http:
+      paths:
+      - backend:
+          serviceName: whoami
+          servicePort: 80
diff --git a/whoami-service.yml b/whoami-service.yml
@@ -0,0 +1,15 @@
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: whoami
+  namespace: whoami
+  labels:
+    app: whoami
+spec:
+  type: ClusterIP
+  ports:
+  - port: 80
+    name: whoami
+  selector:
+    app: whoami
diff --git a/whoami-namespace.yml b/whoami-namespace.yml
@@ -0,0 +1,5 @@
+---
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: whoami
diff --git a/whoami-deployment.yml b/whoami-deployment.yml
@@ -0,0 +1,16 @@
+kind: Deployment
+apiVersion: extensions/v1beta1
+metadata:
+  name: whoami
+  namespace: whoami
+spec:
+  replicas: 2
+  template:
+    metadata:
+      labels:
+        app: whoami
+    spec:
+      containers:
+      - name: whoami
+        image: containous/whoami
+        imagePullPolicy: Always
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