Merge pull request #3 from bespinian/k8s

Add plain k8s setup

README.md

@@ -62,3 +62,7 @@ graph LR;
 
     User-- :8000 --> Traeffik
 ```
+
+### Kubernetes with plain YML files
+
+There is a plain YML Kubernetes setup. Have a look at the instructions in its [README](./k8s/README.md).

k8s/README.md

@@ -0,0 +1,42 @@
+# Kubernetes Deployment
+
+This folder contains plain YML files for a Kubernetes setup of our todo app. It is basically the
+same architecture as the [Docker Compose setup](../).
+
+You can install this in a local Kubernetes cluster using Docker Desktop. In this case you also need
+to install Traefik as Ingress controller. If you install this in some other cluster, you might
+already have an ingress controller and don't need Traefik. That's up to you.
+
+## Prerequisites
+
+You need a Kubernetes cluster of some sort. If you don't have one at hand, just activate the one
+in Docker Desktop. The internet tells you how.
+
+If you have no ingress controller in your cluster, install Traefik as follows:
+
+```sh
+kubectl create ns traefik
+kubectl -n traefik apply -f k8s/traefik
+```
+
+## Install ICT
+
+The provided YAML files assume you have a local cluster and therefore access to it via localhost.
+If you're working with a "real" remote cluster, you might need to change the
+[Ingress Resource](./apps/ingress.yaml).
+
+```sh
+kubectl create namespace todo
+kubectl --namespace todo apply -f k8s/services
+kubectl --namespace todo apply -f k8s/apps
+```
+
+In a remote cluster, you should be done and be able to open the app in your browser.
+
+In a local cluster, we now need to open a port-forward to Traefik. Then we can access the app on
+localhost as usual.
+
+```sh
+kubectl --namespace traefik port-forward services/traefik-web 8000:80
+open localhost:8000
+```

k8s/apps/frontend.yaml

@@ -0,0 +1,53 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: frontend
+spec:
+  replicas: 2
+  selector:
+    matchLabels:
+      app: frontend
+  template:
+    metadata:
+      labels:
+        app: frontend
+    spec:
+      containers:
+        - name: frontend
+          image: ghcr.io/bespinian/insanely-complex-todo/frontend:latest
+          readinessProbe:
+            initialDelaySeconds: 1
+            periodSeconds: 10
+            httpGet:
+              port: 80
+              path: /
+          livenessProbe:
+            initialDelaySeconds: 1
+            periodSeconds: 10
+            httpGet:
+              port: 80
+              path: /
+          resources:
+            requests:
+              memory: "50Mi"
+              cpu: "50m"
+            limits:
+              memory: "128Mi"
+              cpu: "500m"
+          ports:
+            - containerPort: 80
+              name: web
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: frontend
+spec:
+  ports:
+    - port: 80
+      protocol: TCP
+      targetPort: web
+      name: web
+  selector:
+    app: frontend
+  type: ClusterIP

k8s/apps/ingress.yaml

@@ -0,0 +1,29 @@
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: frontend
+spec:
+  rules:
+    - http:
+        paths:
+          - path: /
+            pathType: Prefix
+            backend:
+              service:
+                name: frontend
+                port:
+                  number: 80
+          - path: /api/tasks
+            pathType: Prefix
+            backend:
+              service:
+                name: tasks
+                port:
+                  number: 80
+          - path: /ws
+            pathType: Prefix
+            backend:
+              service:
+                name: websocket-server
+                port:
+                  number: 80

k8s/apps/tasks-api.yaml

@@ -0,0 +1,54 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: tasks
+spec:
+  replicas: 2
+  selector:
+    matchLabels:
+      app: tasks
+  template:
+    metadata:
+      labels:
+        app: tasks
+    spec:
+      containers:
+        - name: tasks
+          image: ghcr.io/bespinian/insanely-complex-todo/tasks:latest
+          env:
+            - name: MONGODB_URI
+              value: mongodb://mongo
+            - name: REDIS_URL
+              value: redis://redis/0
+          readinessProbe:
+            initialDelaySeconds: 1
+            periodSeconds: 10
+            httpGet:
+              port: 3000
+              path: livez
+          livenessProbe:
+            initialDelaySeconds: 1
+            periodSeconds: 10
+            httpGet:
+              port: 3000
+              path: readyz
+          resources:
+            requests:
+              memory: "50Mi"
+              cpu: "50m"
+            limits:
+              memory: "128Mi"
+              cpu: "500m"
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: tasks
+spec:
+  ports:
+    - port: 80
+      protocol: TCP
+      targetPort: 3000
+  selector:
+    app: tasks
+  type: ClusterIP

k8s/apps/websocket-server.yaml

@@ -0,0 +1,44 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: websocket-server
+spec:
+  replicas: 2
+  selector:
+    matchLabels:
+      app: websocket-server
+  template:
+    metadata:
+      labels:
+        app: websocket-server
+    spec:
+      containers:
+        - name: websocket-server
+          image: ghcr.io/bespinian/insanely-complex-todo/websocket-server:latest
+          env:
+            - name: REDIS_URL
+              value: redis://redis/0
+            - name: WEBSOCKET_SERVER_HOST
+              value: "0.0.0.0"
+            - name: WEBSOCKET_SERVER_PORT
+              value: "8765"
+          resources:
+            requests:
+              memory: "128Mi"
+              cpu: "100m"
+            limits:
+              memory: "512Mi"
+              cpu: "500m"
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: websocket-server
+spec:
+  ports:
+    - port: 80
+      protocol: TCP
+      targetPort: 8765
+  selector:
+    app: websocket-server
+  type: ClusterIP

k8s/services/mongodb.yaml

@@ -0,0 +1,58 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: mongo
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: mongo
+  template:
+    metadata:
+      labels:
+        app: mongo
+    spec:
+      containers:
+        - name: mongo
+          image: mongo:8.0
+          resources:
+            requests:
+              memory: "100Mi"
+              cpu: "100m"
+            limits:
+              memory: "256Mi"
+              cpu: "500m"
+          ports:
+            - containerPort: 27017
+          volumeMounts:
+            - name: mongo-data
+              mountPath: /data/db
+      volumes:
+        - name: mongo-data
+          persistentVolumeClaim:
+            claimName: mongo-data
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: mongo
+spec:
+  ports:
+    - port: 27017
+      protocol: TCP
+      targetPort: 27017
+  selector:
+    app: mongo
+  type: ClusterIP
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: mongo-data
+spec:
+  resources:
+    requests:
+      storage: 50M
+  volumeMode: Filesystem
+  accessModes:
+    - ReadWriteOnce

k8s/services/redis.yaml

@@ -0,0 +1,42 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: redis
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: redis
+  template:
+    metadata:
+      labels:
+        app: redis
+    spec:
+      containers:
+        - name: redis
+          image: redis:7-alpine
+          resources:
+            requests:
+              memory: "50Mi"
+              cpu: "100m"
+            limits:
+              memory: "256Mi"
+              cpu: "500m"
+          readinessProbe:
+            exec:
+              command: ["redis-cli", "--raw", "incr", "ping"]
+          ports:
+            - containerPort: 6379
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: redis
+spec:
+  ports:
+    - port: 6379
+      protocol: TCP
+      targetPort: 6379
+  selector:
+    app: redis
+  type: ClusterIP

k8s/traefik/deployment.yaml

@@ -0,0 +1,37 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: traefik
+  namespace: traefik
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: traefik
+  template:
+    metadata:
+      labels:
+        app: traefik
+    spec:
+      serviceAccountName: traefik-account
+      containers:
+        - name: traefik
+          image: traefik:v3.1
+          args:
+            - "--log.level=info"
+            - "--api.insecure=true"
+            - "--entryPoints.web.address=:80"
+            - "--providers.kubernetesingress"
+            - "--ping.entrypoint=traefik"
+          resources:
+            requests:
+              memory: "50Mi"
+              cpu: "100m"
+            limits:
+              memory: "128Mi"
+              cpu: "500m"
+          ports:
+            - containerPort: 80
+              name: web
+            - containerPort: 8080
+              name: dashboard