k8s_tips

k8s_tips.md

Pod log 寫到不同檔案

傳遞 Pod 資訊僅能透過 環境變數 與 檔案

• https://kubernetes.io/docs/tasks/inject-data-application/environment-variable-expose-pod-information/#the-downward-api

使用環境變數搭配 envsubst 設定 nginx configuration file 方法

• https://serverfault.com/questions/577370/how-can-i-use-environment-variables-in-nginx-conf

共用 Deployment 設定檔

看起來只能用參數化的方式

在 osx 使用 envsubst 的方法

brew install gettext
brew link --force gettext 

sample:

curl -O https://gist.githubusercontent.com/phstudy/dfe627d955d3a8bfec18a258fd679c62/raw/a666faf4252a809ec689d75b0e5539849f166d75/nginx-deployment.yaml.tmpl

DEPLOYMENT_NAME=nginx-deployment-1 envsubst < nginx-deployment.yaml.tmpl | kubectl create -f -

DEPLOYMENT_NAME=nginx-deployment-2 envsubst < nginx-deployment.yaml.tmpl | kubectl create -f -

DEPLOYMENT_NAME=nginx-deployment-3 envsubst < nginx-deployment.yaml.tmpl | kubectl create -f -

Memory 使用超過時，pod 被 kill 的行為

• If a Container exceeds its memory limit, it might be terminated. If it is restartable, the kubelet will restart it, as with any other type of runtime failure.

• If a Container exceeds its memory request, it is likely that its Pod will be evicted whenever the node runs out of memory.

• A Container might or might not be allowed to exceed its CPU limit for extended periods of time. However, it will not be killed for excessive CPU usage.

• To determine whether a Container cannot be scheduled or is being killed due to resource limits, see the Troubleshooting section.

References:

• [How Pods with resource limits are run] (https://kubernetes.io/docs/concepts/configuration/manage-compute-resources-container/#how-pods-with-resource-limits-are-run)

• Troubleshooting