「Kubernetes 實作手冊：基礎入門篇」學習筆記（七）：使用 kubeconfig 配置叢集

「Kubernetes 實作手冊：基礎入門篇」Study Notes
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前言

本文為「Kubernetes 實作手冊：基礎入門篇」課程的學習筆記。

簡介

kubeconfig 用於管理多個 Kubernetes 的叢集、使用者、命名空間及認證等資訊。

使用

kubectl 預設會去找 $HOME/.kube/config 路徑。

以 Rancher 建立的叢集為例，定義了 Cluster、Context 和 User 資訊，其 kubeconfig 檔如下：

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apiVersion: v1
kind: Config
clusters:
- name: "sandbox"
  cluster:
    server: "https://172.17.8.111/k8s/clusters/c-xxlj4"
    certificate-authority-data: "LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCk1JSUM3akNDQ\
      WRhZ0F3SUJBZ0lCQURBTkJna3Foa2lHOXcwQkFRc0ZBREFvTVJJd0VBWURWUVFLRXdsMGFHVXQKY\
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- name: "sandbox-k8s-dev"
  cluster:
    server: "https://10.0.2.15:6443"
    certificate-authority-data: "LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCk1JSUN3akNDQ\
      WFxZ0F3SUJBZ0lCQURBTkJna3Foa2lHOXcwQkFRc0ZBREFTTVJBd0RnWURWUVFERXdkcmRXSmwKT\
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      klDQVRFLS0tLS0K"

users:
- name: "sandbox"
  user:
    token: "kubeconfig-user-g8s6b.c-xxlj4:ffb8wjsbnbd8vbx8xj7cqxnrmhv2pflf84l2pwwvlxdcdfn6ssbjw7"

contexts:
- name: "sandbox"
  context:
    user: "sandbox"
    cluster: "sandbox"
- name: "sandbox-k8s-dev"
  context:
    user: "sandbox"
    cluster: "sandbox-k8s-dev"

current-context: "sandbox"

Rancher 定義了兩個叢集，一個是 Rancher Server，另一個是 Kubernetes API Server。

做法

將以上 kubeconfig 檔存成名為 rancher 的檔案。

指令

使用 config view 指令查看名為 rancher 的 kubeconfig 檔。例如：

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kubectl config view --kubeconfig rancher

使用 config get-contexts 指令取得 rancher 環境下的 Cluster 列表。例如：

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kubectl config get-contexts --kubeconfig rancher

切換在 rancher 環境裡，要使用的 Cluster。例如：

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kubectl config use-context sandbox --kubeconfig rancher

顯示在 rancher 環境裡，正在使用的 Cluster。例如：

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kubectl config current-context --kubeconfig rancher

取得 Pod 列表。

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kubectl get pods -n kube-system --kubeconfig rancher

參考資料