新增learn-kubernetes（https://github.com/yyong-brs/learn-kubernetes）相关文件

learn/learn-kubernetes-master/kiamol/ch19/lab/README.md

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+# ch19 lab
+
+## Setup
+
+Deploy metrics-server if you need it (check with `kubectl top nodes` - no stats means you need it):
+
+```
+kubectl apply -f metrics-server/
+```
+
+Run the app:
+
+```
+kubectl apply -f lab/pi/
+```
+
+Confirm the metrics are coming through:
+
+```
+kubectl top pods -l app=pi-web-lab
+```
+
+> Browse to the app and check the CPU spikes - e.g. http://localhost:8032/?dp=100000
+
+## Sample Solution
+
+You need to label your node to indicate it's in the EU region - you can use any key and value for this, but you'll need to use the same in your affinity rules:
+
+```
+kubectl label node --all kiamol.net/region=eu
+```
+
+### Pod with affinity rules 
+
+The updated deployment in [solution/pi.yaml](./solution/pi.yaml) adds these settings:
+
+- **node affinity** - require to run on nodes with region=eu
+- **pod anti-affinity** - prefer to run on nodes without any other Pi pods
+- **resources** - add memory request for the HPA to use
+- **replicas** - start with 2 as that's the desired minimum
+
+```
+kubectl apply -f lab/solution/pi.yaml
+```
+
+> You'll have two Pods running; browse to the app in a few tabs and both will spike CPU
+
+### HPA for scaling on CPU
+
+The HPA spec in [solution/hpa-cpu.yaml](./solution/hpa-cpu.yaml) scales from 2 to 5 Pods based on target CPU utilization of 50%.
+
+```
+kubectl apply -f lab/solution/hpa-cpu.yaml
+```
+
+> Make lots of browser requests in different tabs (or adapt the `ch19/loadpi` script in) and you'll see the Pods scale up to a maximum of five replicas:
+
+![Horizontal pod autoscaling in action](./solution/hpa.png)
+
+
+## Teardown
+
+Delete all the resources:
+
+```
+kubectl delete all,hpa -l kiamol=ch19-lab
+```
+
+And metrics-server if you deployed it:
+
+```
+kubectl delete -f metrics-server/
+```

learn/learn-kubernetes-master/kiamol/ch19/lab/pi/pi.yaml

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+apiVersion: v1
+kind: Service
+metadata:
+  name: pi-web
+  labels:
+    kiamol: ch19-lab
+spec:
+  ports:
+    - port: 8032
+      targetPort: http
+  selector:
+    app: pi-web-lab
+  type: LoadBalancer
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: pi-web-lab
+  labels:
+    kiamol: ch19-lab
+spec:
+  selector:
+    matchLabels:
+      app: pi-web-lab
+  replicas: 1
+  template:
+    metadata:
+      labels:
+        app: pi-web-lab    
+    spec:
+      containers:
+        - image: kiamol/ch05-pi
+          command: ["dotnet", "Pi.Web.dll", "-m", "web"]
+          name: web
+          ports:
+            - containerPort: 80
+              name: http
+          resources:
+            limits:
+              cpu: 200m

learn/learn-kubernetes-master/kiamol/ch19/lab/solution/hpa-cpu.yaml

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+apiVersion: autoscaling/v1
+kind: HorizontalPodAutoscaler
+metadata:
+  name: pi-cpu
+  labels:
+    kiamol: ch19-lab
+spec:
+  scaleTargetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: pi-web-lab
+  minReplicas: 2
+  maxReplicas: 5
+  targetCPUUtilizationPercentage: 50

learn/learn-kubernetes-master/kiamol/ch19/lab/solution/pi.yaml

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+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: pi-web-lab
+  labels:
+    kiamol: ch19-lab
+spec:
+  selector:
+    matchLabels:
+      app: pi-web-lab
+  replicas: 2
+  template:
+    metadata:
+      labels:
+        app: pi-web-lab
+    spec:
+      containers:
+        - image: kiamol/ch05-pi
+          command: ["dotnet", "Pi.Web.dll", "-m", "web"]
+          name: web
+          ports:
+            - containerPort: 80
+              name: http
+          resources:
+            limits:
+              cpu: 200m
+            requests:
+              cpu: 100m      
+      affinity:
+        nodeAffinity:
+          requiredDuringSchedulingIgnoredDuringExecution:
+            nodeSelectorTerms:
+              - matchExpressions:
+                - key: kiamol.net/region
+                  operator: In
+                  values:
+                  - eu
+        podAntiAffinity:
+          preferredDuringSchedulingIgnoredDuringExecution:
+            - weight: 1
+              podAffinityTerm: 
+                labelSelector:
+                  matchExpressions:
+                    - key: app
+                      operator: In
+                      values:
+                      - pi-web-lab
+                topologyKey: "kubernetes.io/hostname"