如何将 kubectl describe 的输出格式化为 JSON

Posted 2023-02-23

【中文标题】如何将 kubectl describe 的输出格式化为 JSON

【英文标题】：How to format the output of kubectl describe to JSON

【发布时间】：2016-09-24 16:10:50

【问题描述】：

kubectl get 命令有这个标志-o 来格式化输出。

是否有类似的方式来格式化kubectl describe 命令的输出？

例如：

kubectl describe -o="jsonpath=..." pods my-rc

将为my-rc 复制控制器中的 pod 列表打印 JSON 格式。但是-o 不接受describe 命令。

【参考方案1】：

kubectl 不支持 -o yaml/json 进行 describe，但您仍然可以使用其他一些命令来获取 describe 中的信息，例如：

kubectl get events

【参考方案2】：

正如@janekuto 建议的那样

describe不能用于显示json格式的数据

请看我的回答here。 jq 确实是一个强大的实用程序，可以玩 kubectl 的 json 显示。您可以使用jq 做很多事情而无需付出太多努力。

kubectl - format the resource quota values in json format

【讨论】：

好吧，我也这么说，并要求使用链接***.com/questions/56250571/…

...如果您首先设法在 json 中获得描述输出...

【参考方案3】：

就我而言，我需要从服务中获取负载均衡器地址。我使用kubectl get service：

$ kubectl -n <namespace> -ojson get service <service>


    "apiVersion": "v1",
    "kind": "Service",
    [...]
    "status": 
        "loadBalancer": 
            "ingress": [
                
                    "hostname": "internal-xxxxxxxxxxxxxxxxxxxxxxxxxxx-yyyyyyyyyy.us-east-1.elb.amazonaws.com"
                
     [...]

【参考方案4】：

kubectl describe 不支持-o 或等效项。它意味着人类可读而不是脚本友好。你可以用kubectl get pods -l <selector_of_your_rc> -o <output_format>实现你所描述的，例如：

$ kubectl get pods -l app=guestbook,tier=frontend -o name
pod/frontend-a4kjz
pod/frontend-am1ua
pod/frontend-yz2dq

【参考方案5】：

根据kubectl help describe的输出，貌似不支持结构化输出：

$ kubectl help describe
Show details of a specific resource or group of resources.

This command joins many API calls together to form a detailed description of a
given resource or group of resources.

$ kubectl describe TYPE NAME_PREFIX

will first check for an exact match on TYPE and NAME_PREFIX. If no such resource
exists, it will output details for every resource that has a name prefixed with NAME_PREFIX

Possible resource types include (case insensitive): pods (po), services (svc), deployments,
replicasets (rs), replicationcontrollers (rc), nodes (no), events (ev), limitranges (limits),
persistentvolumes (pv), persistentvolumeclaims (pvc), resourcequotas (quota), namespaces (ns),
serviceaccounts, ingresses (ing), horizontalpodautoscalers (hpa), daemonsets (ds), configmaps,
componentstatuses (cs), endpoints (ep), and secrets.

Usage:
  kubectl describe (-f FILENAME | TYPE [NAME_PREFIX | -l label] | TYPE/NAME) [flags]

Examples:
# Describe a node
kubectl describe nodes kubernetes-minion-emt8.c.myproject.internal

# Describe a pod
kubectl describe pods/nginx

# Describe a pod identified by type and name in "pod.json"
kubectl describe -f pod.json

# Describe all pods
kubectl describe pods

# Describe pods by label name=myLabel
kubectl describe po -l name=myLabel

# Describe all pods managed by the 'frontend' replication controller (rc-created pods
# get the name of the rc as a prefix in the pod the name).
kubectl describe pods frontend

Flags:
  -f, --filename=[]: Filename, directory, or URL to a file containing the resource to describe
  -l, --selector="": Selector (label query) to filter on

Global Flags:
      --alsologtostderr[=false]: log to standard error as well as files
      --certificate-authority="": Path to a cert. file for the certificate authority.
      --client-certificate="": Path to a client certificate file for TLS.
      --client-key="": Path to a client key file for TLS.
      --cluster="": The name of the kubeconfig cluster to use
      --context="": The name of the kubeconfig context to use
      --insecure-skip-tls-verify[=false]: If true, the server's certificate will not be checked for validity. This will make your HTTPS connections insecure.
      --kubeconfig="": Path to the kubeconfig file to use for CLI requests.
      --log-backtrace-at=:0: when logging hits line file:N, emit a stack trace
      --log-dir="": If non-empty, write log files in this directory
      --log-flush-frequency=5s: Maximum number of seconds between log flushes
      --logtostderr[=true]: log to standard error instead of files
      --match-server-version[=false]: Require server version to match client version
      --namespace="": If present, the namespace scope for this CLI request.
      --password="": Password for basic authentication to the API server.
  -s, --server="": The address and port of the Kubernetes API server
      --stderrthreshold=2: logs at or above this threshold go to stderr
      --token="": Bearer token for authentication to the API server.
      --user="": The name of the kubeconfig user to use
      --username="": Username for basic authentication to the API server.
      --v=0: log level for V logs
      --vmodule=: comma-separated list of pattern=N settings for file-filtered logging