在linux中，解析json一般都会使用jq，jq固然好用，但是要额外安装就不太友好了。如果你在网上搜索通过shell来解析json的方法，你会发现都是些啥玩意儿。既然如此，那就动手撸一个吧。

有以下特性：

• 她能兼容jq的路径表达式

  • .name
  • .[0].name
  • .[0][0].name
  • ...
• 纯shell，其实用的是awk。纯bash不好搞，就曲线救一下国呗

代码如下，拿去不谢。转载请标出处。转载请标出处。转载请标出处。

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正在运行的gitlab集群突然抽风，具体故障现象如下。

环境信息：gitlab部署在k8s集群内，采用官方helm包部署，gitlab版本为14.10.x。

故障现象：项目相关的操作有几率报错

• 新建：创建项目有几率失败，并报错
• 查看项目：进入项目内，有几率刷不出代码树，并报错，报错信息 An error occurred while fetching folder content.
• 删除项目：项目删不掉

查看Gitaly服务的日志，发现是Praefect服务调用Gitaly的健康检查接口报错，错误关键信息为 PermissionDenied。

{"correlation_id":"01G7BX3DR59H35EYHPMKHNVBC0","error":"rpc error: code = PermissionDenied desc = permission denied","grpc.code":"PermissionDenied","grpc.meta.auth_version":"v2","grpc.meta.deadline_type":"unknown","grpc.meta.method_type"
:"unary","grpc.method":"Check","grpc.request.deadline":"2022-07-07T08:39:54.207","grpc.request.fullMethod":"/grpc.health.v1.Health/Check","grpc.request.payload_bytes":0,"grpc.response.payload_bytes":0,"grpc.service":"grpc.health.v1.Healt
h","grpc.start_time":"2022-07-07T08:39:53.208","grpc.time_ms":0.285,"level":"warning","msg":"finished unary call with code PermissionDenied","peer.address":"10.42.1.134:51266","pid":12,"span.kind":"server","system":"grpc","time":"2022-07-07T08:39:53.208Z"}
{"correlation_id":"01G7BX3EQJZJFT996MD2KF2HXW","error":"rpc error: code = PermissionDenied desc = permission denied","grpc.code":"PermissionDenied","grpc.meta.auth_version":"v2","grpc.meta.deadline_type":"unknown","grpc.meta.method_type":"unary","grpc.method":"Check","grpc.request.deadline":"2022-07-07T08:39:55.212","grpc.request.fullMethod":"/grpc.health.v1.Health/Check","grpc.request.payload_bytes":0,"grpc.response.payload_bytes":0,"grpc.service":"grpc.health.v1.Health","grpc.start_time":"2022-07-07T08:39:54.213","grpc.time_ms":0.201,"level":"warning","msg":"finished unary call with code PermissionDenied","peer.address":"10.42.1.134:51266","pid":12,"span.kind":"server","system":"grpc","time":"2022-07-07T08:39:54.213Z"}

*** /var/log/gitaly/gitaly_ruby_json.log ***
{"type":"gitaly-ruby","grpc.start_time":"2022-07-07T08:39:53Z","grpc.time_ms":0.286,"grpc.code":"OK","grpc.method":"Check","grpc.service":"grpc.health.v1.Health","pid":35,"correlation_id":"c486ca8b2bbc3eb6736d533c38cf6017","time":"2022-07-07T08:39:53.642Z"}
{"type":"gitaly-ruby","grpc.start_time":"2022-07-07T08:39:53Z","grpc.time_ms":17.012,"grpc.code":"OK","grpc.method":"Check","grpc.service":"grpc.health.v1.Health","pid":36,"correlation_id":"71bff8c80424d633989f5daeb29111c3","time":"2022-07-07T08:39:53.658Z"}

*** /var/log/gitaly/gitaly.log ***
{"correlation_id":"01G7BX3FPZ8BTMCA0RY5754JGJ","error":"rpc error: code = PermissionDenied desc = permission denied","grpc.code":"PermissionDenied","grpc.meta.auth_version":"v2","grpc.meta.deadline_type":"unknown","grpc.meta.method_type":"unary","grpc.method":"Check","grpc.request.deadline":"2022-07-07T08:39:56.217","grpc.request.fullMethod":"/grpc.health.v1.Health/Check","grpc.request.payload_bytes":0,"grpc.response.payload_bytes":0,"grpc.service":"grpc.health.v1.Health","grpc.start_time":"2022-07-07T08:39:55.218","grpc.time_ms":0.135,"level":"warning","msg":"finished unary call with code PermissionDenied","peer.address":"10.42.1.134:51266","pid":12,"span.kind":"server","system":"grpc","time":"2022-07-07T08:39:55.218Z"}
{"correlation_id":"01G7BX3GPCRD1RPMN7F3WN6X14","error":"rpc error: code = PermissionDenied desc = permission denied","grpc.code":"PermissionDenied","grpc.meta.auth_version":"v2","grpc.meta.deadline_type":"unknown","grpc.meta.method_type":"unary","grpc.method":"Check","grpc.request.deadline":"2022-07-07T08:39:57.222","grpc.request.fullMethod":"/grpc.health.v1.Health/Check","grpc.request.payload_bytes":0,"grpc.response.payload_bytes":0,"grpc.service":"grpc.health.v1.Health","grpc.start_time":"2022-07-07T08:39:56.223","grpc.time_ms":0.189,"level":"warning","msg":"finished unary call with code PermissionDenied","peer.address":"10.42.1.134:51266","pid":12,"span.kind":"server","system":"grpc","time":"2022-07-07T08:39:56.223Z"}

解决：服务器之间做好时间同步就好了

官方issue: Permission denied between Gitlab and Praefect

1 环境介绍

虽然 kubeadm, kops, kubespray 以及 rke, kubesphere 等工具可以快速部署 K8s 集群，但是依然会有很多人热衷与使用二进制部署 K8s 集群。

二进制部署可以加深对 K8s 各组件的理解，可以灵活地将各个组件部署到不同的机器，以满足自身的要求。还可以生成一个超长时间自签证书，比如 99 年，免去忘记更新证书过期带来的生产事故。

本文基于当前(2021-12-31)最新版本 K8s 1.23.1，总体和网上的 1.20,1.22 等版本的部署方式没有太大的区别，主要参考了韩先超老师的 K8s 1.20 版本的二进制部署教程。

另外，我的环境是使用 m1 芯片的 macbook 运行的 ubuntu 20.04 TLS 虚拟机搭建，因此本次环境搭建 K8s 是基于 arm64 架构的。

1.0 书写约定

• 命令行输入，均以 ➜ 符号表示
• 注释使用 # 或 // 表示
• 执行命令输出结果，以空行分隔

1.1 规划

1.2 环境配置

• 设置主机名

  # 10.211.55.4 主机
  ➜ sudo hostnamectl set-hostname ubuntu-k8s-master-01
  # 10.211.55.5 主机
  ➜ sudo hostnamectl set-hostname ubuntu-k8s-worker-01

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Question 1

Task weight: 1%

You have access to multiple clusters from your main terminal through kubectl contexts. Write all context names into /opt/course/1/contexts, one per line.

From the kubeconfig extract the certificate of user restricted@infra-prod and write it decoded to /opt/course/1/cert.

题目解析：

• 考点

  • kubectl

• 解题

  ➜ kubectl config get-contexts -o name > /opt/course/1/contexts
  
  # 从 .kube/config 文件中找到
  - name: restricted@infra-prod
    user
      client-certificate-data: LS0tLS1CRUdJ...
  ➜ echo LS0tLS1CRUdJ... | base64 -d > /opt/course/1/cert

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Question 1

Task weight: 1%

You have access to multiple clusters from your main terminal through kubectl contexts. Write all those context names into /opt/course/1/contexts.

Next write a command to display the current context into /opt/course/1/context_default_kubectl.sh, the command should use kubectl.

Finally write a second command doing the same thing into /opt/course/1/context_default_no_kubectl.sh, but without the use of kubectl.

题目解析：

• 考点

  • kubectl, contexts kubectl 概述 | Kubernetes, kubectl-commands

• 解题

  • 根据题意：Write all those context names into /opt/course/1/contexts

    ➜ kubectl config get-contexts -o name > /opt/course/1/contexts

  • 根据题意：Next write a command to display the current context into /opt/course/1/context_default_kubectl.sh, the command should use kubectl

    ➜ vim /opt/course/1/context_default_kubectl.sh
    kubectl config current-context

  • 根据题意：Finally write a second command doing the same thing into /opt/course/1/context_default_no_kubectl.sh, but without the use of kubectl

    ➜ vim /opt/course/1/context_default_no_kubectl.sh
    grep "current-context: " ~/.kube/config | awk '{print $2}'

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