So formatieren Sie die Ausgabe von kubectl describe in JSON

Question

kubectl get Befehl hat dieses Flag -o, um den Ausgang zu formatieren.

Gibt es eine ähnliche Möglichkeit, die Ausgabe des Befehls kubectl describe zu formatieren?

Zum Beispiel:

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

würde für die Liste der Schoten in my-rc Replikation Controller ein JSON-Format drucken. Aber -o wird für den Befehl describe nicht akzeptiert.

Answer 1

kubectl describe nicht -o oder gleichwertig unterstützt. Es soll vom Menschen lesbar und nicht skriptfreundlich sein. Sie können erreichen, was Sie mit kubectl get pods -l <selector_of_your_rc> -o <output_format> beschrieben, zum Beispiel:

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

Answer 2

Basierend auf der Ausgabe von kubectl help describe, es sieht aus wie es ist nicht strukturierte Ausgabe unterstützt:

$ 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 

Answer 3

In meinem Fall musste ich die Load-Balancer-Adresse aus dem Dienst erhalten. Ich tat es unter Verwendung 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" 
       } 
    [...] 
}