Configuration

KSail supports multiple configuration sources, enabling flexibility from quick prototyping to production-ready GitOps workflows.

How Configuration Works

KSail configuration controls every aspect of cluster creation and workload management—from the Kubernetes distribution to component installation, networking, and GitOps settings.

Configuration can come from multiple sources, allowing you to:

• Commit defaults in ksail.yaml for team consistency
• Override temporarily with CLI flags for testing
• Customize per-environment with environment variables
• Leverage distribution features through native config files

Configuration Sources

KSail accepts configuration from four sources:

Source	Description	Use Case
ksail.yaml	Declarative YAML file	Project defaults, version control
CLI Flags	Command-line arguments	Temporary overrides, CI/CD
Environment Variables	KSAIL_-prefixed variables	Machine-specific settings, secrets
Distribution Config	kind.yaml, k3d.yaml, talos/	Distribution-specific features

Configuration Precedence

When the same setting is specified in multiple sources, KSail uses this order (highest to lowest priority):

1. CLI flags          (e.g., --metrics-server Disabled)
2. Environment vars   (e.g., KSAIL_SPEC_CLUSTER_DISTRIBUTION=K3s)
3. ksail.yaml         (nearest file in current or parent directories)
4. Built-in defaults

Example: If ksail.yaml sets distribution: Vanilla but you run ksail cluster create --distribution K3s, the CLI flag wins and K3s is used.

This precedence model means you can commit sensible defaults while still allowing temporary overrides without editing files.

When to Use What

ksail.yaml

Use declarative configuration for:

• Project-wide defaults that should be version-controlled
• Team consistency so everyone uses the same settings
• Cluster identity (distribution, CNI, GitOps engine)
• Reproducible environments across machines

# yaml-language-server: $schema=https://raw.githubusercontent.com/devantler-tech/ksail/main/schemas/ksail-config.schema.json
apiVersion: ksail.io/v1alpha1
kind: Cluster
spec:
  cluster:
    distribution: Vanilla
    cni: Cilium
    gitOpsEngine: Flux

CLI Flags

Use command-line flags for:

• Temporary overrides during development
• Testing different configurations without editing files
• CI/CD pipelines with environment-specific settings
• Quick experiments before committing changes

# Test with K3s instead of Vanilla (without changing ksail.yaml)
ksail cluster create --distribution K3s

# Disable metrics server for a lightweight test
ksail cluster create --metrics-server Disabled

Environment Variables

Use environment variables for:

• Machine-specific settings (different kubeconfig paths)
• CI/CD secrets and credentials
• Global preferences that apply across all projects

# Set distribution for all ksail commands in this shell
export KSAIL_SPEC_CLUSTER_DISTRIBUTION=K3s
ksail cluster create

Environment variables use the KSAIL_ prefix and follow the configuration path in uppercase with underscores:

Setting	Environment Variable
spec.cluster.distribution	KSAIL_SPEC_CLUSTER_DISTRIBUTION
spec.cluster.cni	KSAIL_SPEC_CLUSTER_CNI
spec.cluster.gitOpsEngine	KSAIL_SPEC_CLUSTER_GITOPSENGINE

Distribution Config

Use distribution configuration files for:

• Distribution-specific features not exposed in ksail.yaml
• Advanced customization (kernel parameters, extra mounts)
• Node topology (control-plane/worker counts, port mappings)

These files follow the native schema for each distribution:

• Vanilla (implemented with Kind): kind.yaml – Kind Configuration
• K3s (implemented with K3d): k3d.yaml – K3d Configuration
• Talos: talos/ – Talos Machine Config

Configuration Guides

• LoadBalancer Configuration – Configure LoadBalancer support across distributions
• Declarative Configuration – Complete ksail.yaml reference

Next Steps

• CLI Flags – All command-line flags by command
• Support Matrix – Platform compatibility reference