--- title: "Introduction To Kubectl" content_type: concept weight: 1 --- Kubectl is the Kubernetes cli version of a swiss army knife, and can do many things. While this Book is focused on using Kubectl to declaratively manage Applications in Kubernetes, it also covers other Kubectl functions. ## Command Families Most Kubectl commands typically fall into one of a few categories: | Type | Used For | Description | |----------------------------------------|----------------------------|----------------------------------------------------| | Declarative Resource Management | Deployment and Operations (e.g. GitOps) | Declaratively manage Kubernetes Workloads using Resource Config | | Imperative Resource Management | Development Only | Run commands to manage Kubernetes Workloads using Command Line arguments and flags | | Printing Workload State | Debugging | Print information about Workloads | | Interacting with Containers | Debugging | Exec, Attach, Cp, Logs | | Cluster Management | Cluster Ops | Drain and Cordon Nodes | ## Declarative Application Management The preferred approach for managing Resources is through declarative files called Resource Config used with the Kubectl *Apply* command. This command reads a local (or remote) file structure and modifies cluster state to reflect the declared intent. {{< alert color="success" title="Apply" >}} Apply is the preferred mechanism for managing Resources in a Kubernetes cluster. {{< /alert >}} ## Printing state about Workloads Users will need to view Workload state. - Printing summarize state and information about Resources - Printing complete state and information about Resources - Printing specific fields from Resources - Query Resources matching labels ## Debugging Workloads Kubectl supports debugging by providing commands for: - Printing Container logs - Printing cluster events - Exec or attaching to a Container - Copying files from Containers in the cluster to a user's filesystem ## Cluster Management On occasion, users may need to perform operations to the Nodes of cluster. Kubectl supports commands to drain Workloads from a Node so that it can be decommission or debugged. ## Porcelain Users may find using Resource Config overly verbose for *Development* and prefer to work with the cluster *imperatively* with a shell-like workflow. Kubectl offers porcelain commands for generating and modifying Resources. - Generating + creating Resources such as Deployments, StatefulSets, Services, ConfigMaps, etc - Setting fields on Resources - Editing (live) Resources in a text editor {{< alert color="warning" title="Porcelain For Dev Only" >}} Porcelain commands are time saving for experimenting with workloads in a dev cluster, but shouldn't be used for production. {{< /alert >}}