kubectl

kubectl (pronounced "kube-control" or "kube-c-t-l") is the command-line tool that communicates with the Kubernetes API server. It translates your commands into API calls and presents the results in a human-readable format.

All kubectl commands follow this pattern:

kubectl [command] [type] [name] [flags]

Examples:

• kubectl get pods - List all pods
• kubectl describe service ui - Get detailed info about the ui service
• kubectl apply -f deployment.yaml - Create resources from a file

kubectl has excellent built-in documentation. Let's explore it:

~$kubectl

kubectl controls the Kubernetes cluster manager.

 Find more information at: https://kubernetes.io/docs/reference/kubectl/

Basic Commands (Beginner):

  create          Create a resource from a file or from stdin

  expose          Take a replication controller, service, deployment or pod and expose it as a new

Kubernetes service

  run             Run a particular image on the cluster

  set             Set specific features on objects

Basic Commands (Intermediate):

  explain         Get documentation for a resource

  get             Display one or many resources

  edit            Edit a resource on the server

  delete          Delete resources by file names, stdin, resources and names, or by resources and

label selector

Deploy Commands:

  rollout         Manage the rollout of a resource

  scale           Set a new size for a deployment, replica set, or replication controller

  autoscale       Auto-scale a deployment, replica set, stateful set, or replication controller

Cluster Management Commands:

  certificate     Modify certificate resources

  cluster-info    Display cluster information

  top             Display resource (CPU/memory) usage

  cordon          Mark node as unschedulable

  uncordon        Mark node as schedulable

  drain           Drain node in preparation for maintenance

  taint           Update the taints on one or more nodes

Troubleshooting and Debugging Commands:

  describe        Show details of a specific resource or group of resources

  logs            Print the logs for a container in a pod

  attach          Attach to a running container

  exec            Execute a command in a container

  port-forward    Forward one or more local ports to a pod

  proxy           Run a proxy to the Kubernetes API server

  cp              Copy files and directories to and from containers

  auth            Inspect authorization

  debug           Create debugging sessions for troubleshooting workloads and nodes

  events          List events

Advanced Commands:

  diff            Diff the live version against a would-be applied version

  apply           Apply a configuration to a resource by file name or stdin

  patch           Update fields of a resource

  replace         Replace a resource by file name or stdin

  wait            Experimental: Wait for a specific condition on one or many resources

  kustomize       Build a kustomization target from a directory or URL

Settings Commands:

  label           Update the labels on a resource

  annotate        Update the annotations on a resource

  completion      Output shell completion code for the specified shell (bash, zsh, fish, or

powershell)

Subcommands provided by plugins:

  connect       The command connect is a plugin installed by the user

Other Commands:

  api-resources   Print the supported API resources on the server

  api-versions    Print the supported API versions on the server, in the form of "group/version"

  config          Modify kubeconfig files

  plugin          Provides utilities for interacting with plugins

  version         Print the client and server version information

Usage:

  kubectl [flags] [options]

Use "kubectl <command> --help" for more information about a given command.

Use "kubectl options" for a list of global command-line options (applies to all commands).

kubectl organizes commands into logical categories. Understanding these categories helps you find the right command for any task.

1. Basic Commands (Beginner & Intermediate)
2. Deploy Commands
3. Cluster Management Commands
4. Troubleshooting and Debugging Commands
5. Advanced Commands
6. Settings Commands
7. Other Commands

Getting Help

kubectl has excellent built-in help:

~$kubectl --help

# Get help for specific commands

~$kubectl get --help

~$kubectl apply --help

# Get resource documentation

~$kubectl explain pod

~$kubectl explain deployment.spec.template

Workshop Patterns

Throughout this workshop, you'll frequently use these kubectl commands:

• kubectl apply -k for Kustomize deployments
• kubectl get pods -n <namespace> for checking application status
• kubectl describe and kubectl logs for troubleshooting
• kubectl port-forward for accessing applications locally

Key Concepts to Remember

• Command pattern: kubectl [command] [type] [name] [flags] - all commands follow this structure
• Get help: Use kubectl --help or kubectl <command> --help to discover options
• Declarative approach: Use kubectl apply -f for production deployments
• Namespace awareness: Always specify -n <namespace> or use -A for all namespaces
• Essential commands: get, describe, logs, apply, port-forward cover most daily tasks