Kubectl¶

Kubectl

A través de la herramienta de línea de comandos kubectl podemos controlar nuestors clústers de Kubernetes.

La configuración de kubectl reside en el archivo config que se encuentra en el directorio $HOME/.kube Aunque si queremos, también podemos especificar otros archivos kubeconfig configurando la variable de entorno KUBECONFIG o configurando la bandera --kubeconfig flag..

Sintaxis¶

Los comandos de Kubectl tienen el siguiente formato:

kubectl [command] [TYPE] [NAME] [flags]

Donde command, TYPE, NAME, y flags son:

command: Operación que se desea realizar sobre uno o más recursos. Por ejemplo: create, get, describe, delete.
TYPE: Indica el tipo de recurso al que se le aplica la operación. Los tipos de recursos son insensibles a las mayúsculas y se pueden indicar tanto en singular, plural o incluso de forma abreviada. Por ejemplo los siguientes comandos producen la misma salida:

kubectl get pod pod1
kubectl get pods pod1
kubectl get po pod1

NAME: Hace referencia al nombre del recurso al que se le va a aplicar dicha operación. Los nombres son sensibles a las mayúsculas. Y si lo omitimos, se nos mostrará la información de todos los recursos disponibles. Por ejemplo: kubectl get pods.

Al realizar una operación en varios recursos, puede especificar cada recurso por tipo y nombre o especificar uno o más archivos:

Para especificar recursos por tipo y nombre:
- Agrupar recursos si son del mismo tipo: TYPE1 name1 name2 name<#>.
  Ejemplo: kubectl get pod example-pod1 example-pod2
- Especificar distintos tipos de recursos individualmente: TYPE1/name1 TYPE1/name2 TYPE2/name3 TYPE<#>/name<#>.
  Ejemplo: kubectl get pod/example-pod1 replicationcontroller/example-rc1
Especificar recursos con uno o más archivos: -f file1 -f file2 -f file<#>
- Utilice YAML mejor que JSON ya que YAML suele ser más user-friendly, sobretodo para ficheros de configuración.
  Ejemplo: kubectl get -f ./pod.yaml
flags: Permite especificar banderas. Por ejemplo, puede utilizar las banderas -s o --server para especificar la dirección y el puerto a la API de Kubernetes.

Atención

Las banderas que especifiquemos a través de la linea de comandos anula los valores predeterminados de las banderas y las variables de entorno correspondientes.

Si necesitas ayuda escribe kubectl help en la consola.

Operaciones¶

La siguiente tabla incluye una breve descripión y la sintaxis general de las operaciones de kubectl:

Operation	Syntax	Description
`alpha`	`kubectl alpha SUBCOMMAND [flags]`	List the available commands that correspond to alpha features, which are not enabled in Kubernetes clusters by default.
`annotate`	`kubectl annotate (-f FILENAME \| TYPE NAME \| TYPE/NAME) KEY_1=VAL_1 ... KEY_N=VAL_N [--overwrite] [--all] [--resource-version=version] [flags]`	Add or update the annotations of one or more resources.
`api-resources`	`kubectl api-resources [flags]`	List the API resources that are available.
`api-versions`	`kubectl api-versions [flags]`	List the API versions that are available.
`apply`	`kubectl apply -f FILENAME [flags]`	Apply a configuration change to a resource from a file or stdin.
`attach`	`kubectl attach POD -c CONTAINER [-i] [-t] [flags]`	Attach to a running container either to view the output stream or interact with the container (stdin).
`auth`	`kubectl auth [flags] [options]`	Inspect authorization.
`autoscale`	`kubectl autoscale (-f FILENAME \| TYPE NAME \| TYPE/NAME) [--min=MINPODS] --max=MAXPODS [--cpu-percent=CPU] [flags]`	Automatically scale the set of pods that are managed by a replication controller.
`certificate`	`kubectl certificate SUBCOMMAND [options]`	Modify certificate resources.
`cluster-info`	`kubectl cluster-info [flags]`	Display endpoint information about the master and services in the cluster.
`completion`	`kubectl completion SHELL [options]`	Output shell completion code for the specified shell (bash or zsh).
`config`	`kubectl config SUBCOMMAND [flags]`	Modifies kubeconfig files. See the individual subcommands for details.
`convert`	`kubectl convert -f FILENAME [options]`	Convert config files between different API versions. Both YAML and JSON formats are accepted.
`cordon`	`kubectl cordon NODE [options]`	Mark node as unschedulable.
`cp`	`kubectl cp <file-spec-src> <file-spec-dest> [options]`	Copy files and directories to and from containers.
`create`	`kubectl create -f FILENAME [flags]`	Create one or more resources from a file or stdin.
`delete`	`kubectl delete (-f FILENAME \| TYPE [NAME \| /NAME \| -l label \| --all]) [flags]`	Delete resources either from a file, stdin, or specifying label selectors, names, resource selectors, or resources.
`describe`	`kubectl describe (-f FILENAME \| TYPE [NAME_PREFIX \| /NAME \| -l label]) [flags]`	Display the detailed state of one or more resources.
`diff`	`kubectl diff -f FILENAME [flags]`	Diff file or stdin against live configuration.
`drain`	`kubectl drain NODE [options]`	Drain node in preparation for maintenance.
`edit`	`kubectl edit (-f FILENAME \| TYPE NAME \| TYPE/NAME) [flags]`	Edit and update the definition of one or more resources on the server by using the default editor.
`exec`	`kubectl exec POD [-c CONTAINER] [-i] [-t] [flags] [-- COMMAND [args...]]`	Execute a command against a container in a pod.
`explain`	`kubectl explain [--recursive=false] [flags]`	Get documentation of various resources. For instance pods, nodes, services, etc.
`expose`	`kubectl expose (-f FILENAME \| TYPE NAME \| TYPE/NAME) [--port=port] [--protocol=TCP\|UDP] [--target-port=number-or-name] [--name=name] [--external-ip=external-ip-of-service] [--type=type] [flags]`	Expose a replication controller, service, or pod as a new Kubernetes service.
`get`	`kubectl get (-f FILENAME \| TYPE [NAME \| /NAME \| -l label]) [--watch] [--sort-by=FIELD] [[-o \| --output]=OUTPUT_FORMAT] [flags]`	List one or more resources.
`kustomize`	`kubectl kustomize <dir> [flags] [options]`	List a set of API resources generated from instructions in a kustomization.yaml file. The argument must be the path to the directory containing the file, or a git repository URL with a path suffix specifying same with respect to the repository root.
`label`	`kubectl label (-f FILENAME \| TYPE NAME \| TYPE/NAME) KEY_1=VAL_1 ... KEY_N=VAL_N [--overwrite] [--all] [--resource-version=version] [flags]`	Add or update the labels of one or more resources.
`logs`	`kubectl logs POD [-c CONTAINER] [--follow] [flags]`	Print the logs for a container in a pod.
`options`	`kubectl options`	List of global command-line options, which apply to all commands.
`patch`	`kubectl patch (-f FILENAME \| TYPE NAME \| TYPE/NAME) --patch PATCH [flags]`	Update one or more fields of a resource by using the strategic merge patch process.
`plugin`	`kubectl plugin [flags] [options]`	Provides utilities for interacting with plugins.
`port-forward`	`kubectl port-forward POD [LOCAL_PORT:]REMOTE_PORT [...[LOCAL_PORT_N:]REMOTE_PORT_N] [flags]`	Forward one or more local ports to a pod.
`proxy`	`kubectl proxy [--port=PORT] [--www=static-dir] [--www-prefix=prefix] [--api-prefix=prefix] [flags]`	Run a proxy to the Kubernetes API server.
`replace`	`kubectl replace -f FILENAME`	Replace a resource from a file or stdin.
`rollout`	`kubectl rollout SUBCOMMAND [options]`	Manage the rollout of a resource. Valid resource types include: deployments, daemonsets and statefulsets.
`run`	`kubectl run NAME --image=image [--env="key=value"] [--port=port] [--dry-run=server\|client\|none] [--overrides=inline-json] [flags]`	Run a specified image on the cluster.
`scale`	`kubectl scale (-f FILENAME \| TYPE NAME \| TYPE/NAME) --replicas=COUNT [--resource-version=version] [--current-replicas=count] [flags]`	Update the size of the specified replication controller.
`set`	`kubectl set SUBCOMMAND [options]`	Configure application resources.
`taint`	`kubectl taint NODE NAME KEY_1=VAL_1:TAINT_EFFECT_1 ... KEY_N=VAL_N:TAINT_EFFECT_N [options]`	Update the taints on one or more nodes.
`top`	`kubectl top [flags] [options]`	Display Resource (CPU/Memory/Storage) usage.
`uncordon`	`kubectl uncordon NODE [options]`	Mark node as schedulable.
`version`	`kubectl version [--client] [flags]`	Display the Kubernetes version running on the client and server.
`wait`	`kubectl wait ([-f FILENAME] \| resource.group/resource.name \| resource.group [(-l label \| --all)]) [--for=delete\|--for condition=available] [options]`	Experimental: Wait for a specific condition on one or many resources.

Para más información visite la documentación de kubectl

Última actualización: 22 de abril de 2021