k8s-launch-kit-shared

k8s-launch-kit (l8k) CLI: Shared patterns for binary location, global flags, output formatting, exit codes, and error handling. Read this before using any…

npx skills add https://github.com/nvidia/k8s-launch-kit --skill k8s-launch-kit-shared

l8k — Shared Reference

Installation

# Build and install (production — copies binary + profiles)
make build && sudo scripts/install.sh

# Development (symlinks into source tree)
make build && scripts/install.sh --dev-env

Install Paths

PathContents
/usr/local/bin/l8kCLI binary (on PATH)
/usr/local/share/l8k/profiles/Go template profiles
/usr/local/share/l8k/presets/Topology presets (per (machineType, gpuType) directories)
/usr/local/share/l8k/l8k-config.yamlDefault config

After installation, l8k is available system-wide.

Binary Discovery (for AI agents)

CRITICAL — follow these steps exactly:

  1. Run which l8k in a single Bash call. If it returns a path, use it. Done.
  2. If which l8k fails (exit code 1), tell the user l8k is not installed. Point them to: make build && sudo scripts/install.sh. Stop — do not proceed.
  3. NEVER do any of the following to find l8k:
    • find or ls commands
    • Spawn a subagent to locate the binary
    • Check multiple paths or directories
    • Explore the repo contents

Available Commands

CommandDescription
l8k discoverDiscover cluster hardware and produce cluster-config.yaml
l8k generateGenerate Kubernetes YAML manifests from config + profile (use --for <preset> to skip cluster discovery for known SKUs)
l8k preset listList bundled topology presets (directory + machineType + gpuType)
l8k preset updateDownload latest topology presets from GitHub
l8k sosreportCollect diagnostic dump from cluster
l8k schemaList all capabilities as JSON (profiles, flags, exit codes)
l8k versionPrint version information

The root command l8k --discover-cluster-config ... still works for backward-compatible full-pipeline usage.

Global Flags

FlagDescription
--kubeconfig <PATH>Path to kubeconfig file (optional — falls back to $KUBECONFIG env var)
--user-config <PATH>Path to user-supplied l8k-config.yaml
--output <FORMAT>Output format: text (default), json
--yes / -yAuto-confirm all prompts (root command only — not available on subcommands; --output json auto-confirms)
--quiet / -qSuppress informational output (errors still shown)
--network-operator-namespace <NS>Override network operator namespace (default: nvidia-network-operator). No-op for l8k discover — discover always bootstraps into nvidia-k8s-launch-kit; the flag still applies to l8k generate / l8k deploy / l8k validate.
--network-namespaces <NS,...>Comma-separated namespaces for the secondary-network CRs + example test DaemonSets; one copy rendered per namespace (shared resources like IPPools/NodePolicies are NOT duplicated). Default: default
--node-selector <LABELS>Restrict to nodes matching labels (comma-separated, ANDed)
--image-pull-secrets <NAMES>Image pull secret names for NicClusterPolicy (comma-separated)

l8k discover and l8k generate both accept the profile flags --fabric, --deployment-type, --multirail, --spectrum-x, --multiplane-mode, and --number-of-planes. Discovery persists the resolved values; later generation reuses them unless another explicit CLI override is supplied.

Agent / JSON Mode

RULE: AI agents MUST always use --output json 2>/dev/null when calling any l8k subcommand. Never use text mode — it produces unstructured output with spinners and ANSI codes that is hard to parse.

Do NOT use --yes with subcommands — it only exists on the root command and will cause "unknown flag" errors. --output json already auto-confirms all prompts (no interactive input needed).

# Correct
l8k discover --output json 2>/dev/null
l8k generate --output json 2>/dev/null

# WRONG — --yes is not a valid flag on subcommands
l8k discover --output json --yes 2>/dev/null
  • stdout: Exactly one JSON object (JSONResult) at completion
  • stderr: Human-readable log lines
  • Pipe with jq for downstream processing: l8k discover ... --output json 2>/dev/null | jq .success

Exit Codes

CodeMeaning
0Success
1General/unknown error
2Validation error — bad flags, missing required arguments, or invalid config
3Cluster error — kubeconfig invalid, API unreachable, missing CRDs, no NVIDIA NICs
4Deployment error — apply failed
5Partial success — discovery ok but deploy failed

Structured Error Output (JSON mode)

{
  "success": false,
  "phase": "discover",
  "deployed": false,
  "error": {
    "code": "CLUSTER_ERROR",
    "message": "cluster discovery failed",
    "category": "cluster",
    "transient": true,
    "suggestion": "Check that kubeconfig is valid and the cluster is reachable"
  },
  "messages": [...]
}

Error categories: validation, cluster, deployment. The transient field hints whether retrying might help.

Schema Discovery

# List all l8k capabilities as JSON
l8k schema

Use l8k schema to programmatically discover available profiles, fabrics, deployment types, flags, exit codes, and output formats.

Security Rules

  • Confirm with the user before executing --deploy on a production cluster
  • Prefer --dry-run for destructive operations
  • Never expose kubeconfig contents in output

Network Operator Namespace Resolution

Applies to l8k generate / l8k deploy / l8k validate only. l8k discover manages its own private namespace (nvidia-k8s-launch-kit) and ignores this flag.

Both nvidia-network-operator and network-operator are common default namespaces for an existing Network Operator install. If l8k generate / l8k deploy / l8k validate can't find Network Operator resources, retry with --network-operator-namespace <correct-namespace>.