Kubernetes Integration

Integrate your Go CLI with Kubernetes using client-go.

Universal Client

Build clients that work everywhere: developer laptops, CI runners, and cluster pods. Automatic config detection handles the differences.

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Overview

A well-designed Kubernetes CLI works seamlessly both on developer laptops and inside cluster pods. This section covers:

• Client Configuration - Automatic config detection for all environments
• RBAC Setup - Service accounts and permissions
• Common Operations - List, patch, and restart resources

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Configuration Flow

graph TB
    Start[Client Request] --> ExplicitKC{Explicit<br/>kubeconfig?}
    ExplicitKC -->|Yes| UseExplicit[Use Specified Path]
    ExplicitKC -->|No| InCluster{In-Cluster<br/>Token Exists?}

    InCluster -->|Yes| UseInCluster[Use In-Cluster Config]
    InCluster -->|No| EnvKC{KUBECONFIG<br/>Env Set?}

    EnvKC -->|Yes| UseEnv[Use KUBECONFIG Path]
    EnvKC -->|No| UseHome[Use ~/.kube/config]

    UseExplicit --> CreateClient[Create Clientset]
    UseInCluster --> CreateClient
    UseEnv --> CreateClient
    UseHome --> CreateClient

    CreateClient --> Ready[Client Ready]

    %% Start node - cyan

    %% Ghostty Hardcore Theme
    style Start fill:#65d9ef,color:#1b1d1e

    %% Decision nodes - orange
    style ExplicitKC fill:#fd971e,color:#1b1d1e
    style InCluster fill:#fd971e,color:#1b1d1e
    style EnvKC fill:#fd971e,color:#1b1d1e

    %% Config resolution nodes - purple
    style UseExplicit fill:#9e6ffe,color:#1b1d1e
    style UseInCluster fill:#9e6ffe,color:#1b1d1e
    style UseEnv fill:#9e6ffe,color:#1b1d1e
    style UseHome fill:#9e6ffe,color:#1b1d1e

    %% Processing and success nodes
    style CreateClient fill:#65d9ef,color:#1b1d1e
    style Ready fill:#a7e22e,color:#1b1d1e

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Quick Start

import "k8s.io/client-go/kubernetes"

// Create a client that works everywhere
client, err := k8s.NewClient(kubeconfig, namespace)
if err != nil {
    return fmt.Errorf("failed to create client: %w", err)
}

// Use the client
deployments, err := client.ListDeployments(ctx)

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Best Practices

Practice	Description
Use contexts everywhere	Pass context.Context to all Kubernetes operations
Handle cancellation	Respect context cancellation for clean shutdowns
Wrap errors with context	Include resource type and name in error messages
Default to current namespace	Match kubectl behavior for namespace resolution
Support both configs	Always handle in-cluster and out-of-cluster scenarios
Minimal RBAC	Request only the permissions your CLI needs

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Build clients that work everywhere: laptop, CI runner, or pod.

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