Kubernetes Cheatsheet

kubectl is the command-line tool for interacting with Kubernetes clusters. It allows you to deploy applications, inspect and manage cluster resources, and view logs. Understanding the basic syntax and commands is essential for working with Kubernetes.

Commands to retrieve information about your Kubernetes cluster, including cluster status, version details, and available API resources. These commands help you understand your cluster's configuration and capabilities.

kubectl configuration manages connections to multiple clusters through the kubeconfig file. Contexts allow you to switch between different clusters, users, and namespaces without changing your kubeconfig file.

Pods are the smallest deployable units in Kubernetes. This section covers essential commands for creating, inspecting, managing, and troubleshooting pods.

Kubernetes deployments manage the creation and updating of replica pods. They provide declarative updates for pods and ReplicaSets, enabling rolling updates, rollbacks, scaling, and other deployment strategies.

Services in Kubernetes provide stable network endpoints to access pods. They enable communication between different components within applications and expose applications to external users.

ConfigMaps and Secrets are Kubernetes resources used to decouple configuration from container images. ConfigMaps store non-sensitive configuration data, while Secrets store sensitive information like passwords and tokens.

Namespaces provide a mechanism for isolating groups of resources within a single cluster. They are particularly useful in environments where many users spread across multiple teams or projects share a Kubernetes cluster. Namespace operations allow you to create, manage, and organize these isolated resource groups.

Resource management in Kubernetes involves creating, viewing, and manipulating various resource types beyond pods and deployments. This includes ReplicaSets, StatefulSets, DaemonSets, and other specialized workloads.

Commands for getting detailed information about Kubernetes resources and modifying them directly. These commands help inspect resource configurations and make changes without manually editing YAML files.

Labels and annotations are key-value pairs attached to Kubernetes objects. Labels are used for selecting and organizing resources, while annotations store non-identifying metadata. Labels can be used with selectors in commands, while annotations typically provide additional information for tools or humans.

Resource quotas and limits help control resource consumption in Kubernetes clusters. Quotas restrict resources at the namespace level, while limits constrain resources at the pod and container level.

Debugging and troubleshooting are essential skills for working with Kubernetes. These kubectl commands help identify and resolve issues with applications, pods, and cluster components.

Kubernetes events provide insights into what's happening inside a cluster, including pod scheduling, resource constraints, and errors. Monitoring these events helps with troubleshooting and understanding cluster behavior.

Port forwarding allows you to access applications running in pods by creating a direct connection from your local machine to the pod. This is useful for debugging, development, and accessing services that aren't exposed through other means.

The kubectl exec and attach commands allow you to run commands inside containers or attach to container processes. These commands are essential for debugging, troubleshooting, and performing administrative tasks within containers.

Kubernetes provides various ways to delete resources with different options for handling dependencies, grace periods, and force deletion. Understanding these commands helps you safely remove resources from your cluster.

The `kubectl apply` command is used for declarative resource management, while `kubectl patch` allows for targeted updates to specific fields without modifying the entire resource.

Generate YAML manifests from imperative kubectl commands using the `--dry-run=client` flag and `-o yaml` output format. This allows you to create resource templates without actually submitting them to the cluster.

Kubectl can output results in various formats to suit different needs. You can customize the output format using the `-o` or `--output` flag to make data more readable or to extract specific information.

Kubectl plugins are standalone executables that extend kubectl functionality. They follow a naming convention of "kubectl-<plugin_name>" and must be executable and available in your PATH.

Kubernetes provides ways to watch resources for real-time changes. This is useful for monitoring resources, building custom controllers, or implementing automated responses to cluster changes.

The kubectl proxy command creates a proxy server between your local machine and the Kubernetes API server, allowing you to access the API server without authentication. This is useful for development, debugging, and exploring the API.

Role-Based Access Control (RBAC) in Kubernetes allows you to control who can access what resources in your cluster. This is managed through kubectl commands that create and manipulate roles, role bindings, service accounts, and cluster-level equivalents.

Kubernetes provides tools to validate resources before applying them to the cluster. This helps catch configuration errors early and ensures resources meet the API requirements.

Boost your kubectl productivity with these time-saving tips, aliases, and shortcuts. These techniques will help you work more efficiently with Kubernetes in your daily operations.