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/
+```