kubectl patch Error from server: cannot restore slice from map 容器环境资源一键清理

拼搏现实的明天。 2022-11-29 08:50 3阅读 0赞

想通过kubectl patch更新deploy的资源，但是出现如下错误：

k8smaster01@/app/tools>kubectl -n ${NAMESPACE} patch deploy aim-realnamegw-1-0-0  -p '{"spec":{"template":{"spec":{"containers":{"resources":{"limits":{"cpu":"0.5","memory":"256Mi"},"requests":{"cpu":"0.5","memory":"256Mi"}}}}}}}'
    Error from server: cannot restore slice from map

但是执行explain路径是正确的呀：

k8smaster01@/home/betadmin>kubectl explain pod.spec.containers.resources
    RESOURCE: resources <Object>
    
    DESCRIPTION:
         Compute Resources required by this container. Cannot be updated. More info:
         https://kubernetes.io/docs/concepts/storage/persistent-volumes#resources
    
         ResourceRequirements describes the compute resource requirements.
    
    FIELDS:
       limits       <map[string]string>
         Limits describes the maximum amount of compute resources allowed. More
    
       requests     <map[string]string>
         Requests describes the minimum amount of compute resources required. If
         Requests is omitted for a container, it defaults to Limits if that is
         explicitly specified, otherwise to an implementation-defined value. More

实际上这个错误的意思是：值的类型错误，不符合deploy的预定，具体来说是containers的值，这里直接是：

{ "resources":{ "limits":{ "cpu":"0.5","memory":"256Mi"},"requests":{ "cpu":"0.5","memory":"256Mi"}}}

这表示containers是对象类型，而实际上container是对象数组类型，可通过explain查看：

k8smaster01@/home/betadmin>kubectl explain pod.spec
    containers   <[]Object> -required-
         List of containers belonging to the pod. Containers cannot currently be
         added or removed. There must be at least one container in a Pod. Cannot be
         updated.

其中类型是<\[ \]Object>表示对象数组。

**解决方案：加上数组标识 \[ \]**

k8smaster01@/app/tools>kubectl -n ${NAMESPACE} patch deploy aim-realnamegw-1-0-0 -p '{"spec":{"template":{"spec":{"containers":[{"name": "aim-realnamegw","resources":{"limits":{"cpu":"0.5","memory":"256Mi"},"requests":{"cpu":"0.5","memory":"256Mi"}}}]}}}}'
    deployment "aim-realnamegw-1-0-0" patched

注意需要指定**name**来指定要修改的元素！

下面附录一个容器环境瘦身的shell脚本：

开发和测试环境常常因资源不足导致部署Pending，可通过如下脚本进行瘦身

#系统瘦身：所有deploy replicas缩为1，所有pod资源缩为 0.5cpu 256M
    #适用于一个deploy中只有一个container的deploy
    #参数1：namespace环境变量
    #环境瘦身
    function Slimming()
    { 
      deployments=$(kubectl get deploy -n ${ NAMESPACE} | grep -v 'NAME' | cut -d ' ' -f 1)
      for element in ${deployments[@]}
      do
        containerName=$(kubectl -n ${ NAMESPACE} get deploy $element -owide | grep -v 'NAME' | awk '{print $7}')
        #${containerName}在json中是字符串类型，json串中必须使用双引号应用
        #不能直接包含在双引号中，否者shell不会替换为参数值
        #通过前后字符串来拼接，注意不要前后字符串都别缺少双引号
        kubectl -n ${NAMESPACE}  patch deploy ${element} -p '{"spec":{"template":{"spec":{"containers":[{"name": "'${containerName}'","resources":{"limits":{"cpu":"1","memory":"1Gi"},"requests":{"cpu":"1","memory":"1Gi"}}}]}}}}'
        kubectl -n ${NAMESPACE}  patch hpa  ${element}  -p '{"spec":{"minReplicas":1,"maxReplicas":1}}'
      done
    }