Kubernetes

Question

我正在创建一个 bash 脚本来自动执行集群中的某些操作。其中一个命令是：kubectl delete -f example.yaml.

问题是当YAML中定义的资源不存在时，打印如下错误：

Error from server (NotFound): error when deleting "example.yaml": deployments.apps "my_app" not found

我希望添加一个额外的步骤，首先检查集群中是否存在 YAML 文件中定义的一组资源。是否有允许我这样做的命令？

从documentation，我发现：

Compares the current state of the cluster against the state that the cluster would be in if the manifest was applied.

kubectl diff -f ./my-manifest.yaml

但我发现很难解析它 returns 的输出。有更好的选择吗？

Answer 1

查明同一对象是否已存在于集群中，正如清单文件中所描述的那样。您可以使用 kubectl diff 命令的 return 代码。

Exit status:
 0 No differences were found.
 1 Differences were found. 
 >1 Kubectl or diff failed with an error.

示例：

kubectl diff -f crazy.yml &>/dev/null
rc=$?
if [ $rc -eq 0 ];then
  echo "Exact Object is already installed on the cluster"
elif [ $rc -eq 1 ];then
  echo "Exact object is not installed, either its not installed or different from the manifest file"
else
  echo "Unable to determine the difference"
fi

或者，如果您想真正解析输出，您可以使用以下环境变量以所需格式打印差异输出：

KUBECTL_EXTERNAL_DIFF environment variable can be used to select your own diff command. Users can use external commands with params too,

Kubernetes - 检查 YAML 文件中定义的资源是否存在

Kubernetes - check if resources defined in YAML file exist

bash

kubectl

Compares the current state of the cluster against the state that the cluster would be in if the manifest was applied.