# Spring to Kubernetes Easier and Faster - Ray Tsang

{%hackmd WDaotZ6JSn6UdPEhrgLeyw %}

> 從這開始
>

[12 factor](https://12factor.net/)
Containers

Choose a JDK
Contain Aware
Open JDK 8u192 or above

docker run -ti --rm --memory=256m --cpus=4 openjdk:8u222-slim -XX:+PrintFlagsFinal | grep MaxHeap

Native Memory Tracking

Container Best Practices https://saturnism.me/talk/docker-tips-and-tricks/

Just Jib It

Don't write to container filesystem!
Those logs!

Keep Base Deployment Simple

get.k3s.io

kubectl create deployment demo-app --imag=gcr.io/wise-coyote-827/jib-demon --dry-run -oymal

skaffold
https://github.com/GoogleContainerTools/skaffold

Haleth Check
Liveness Probe
Readiness Probe<--must have
Signals
Livecycle Hooks

Anatomy of a Graceful Shutdown
1. Receive SIGTERM or PreStop Lifecycle Hook
2. Fail Readiness Probe
3. Receive requests until Kubernetes detects readiness probe failure
4. Kubernetes removes pod endpoint from Service
5. Finish serving in-flight requests
6. Shutdown

###### tags: `jcconf`