Importing Existing YAML

Chant can parse existing Kubernetes YAML manifests and generate typed TypeScript source files. This is useful for migrating existing infrastructure to chant.

How it works

Input YAML → parse → generate TypeScript → export typed resources

The importer reads multi-document YAML, identifies each resource’s apiVersion and kind, and generates the corresponding typed constructor call. The output is a valid .k8s.ts file you can immediately build with chant build.

Running the import roundtrip

From the lexicons/k8s directory:

# Full roundtrip — clones kubernetes/examples, imports, serializes, compares
just full-roundtrip

# Skip clone if repo is already cached
just full-roundtrip --skip-clone

# Verbose output + filter to a specific manifest
just full-roundtrip --skip-clone --verbose --manifest guestbook

# Skip the serialize phase (parse + generate only)
just full-roundtrip --skip-clone --skip-serialize

Parse-only mode

For quick validation without the full serialize cycle:

just import-samples --skip-clone --verbose

# Filter to a specific manifest
just import-samples --skip-clone --verbose --manifest guestbook

This runs the YAML → TypeScript generation but skips the round-trip comparison.

What “pass” means

A passing roundtrip means the serialized YAML, when re-parsed, produces the same number of resources with matching kind values. Exact YAML comparison is intentionally skipped — key ordering, quoting, and comments differ between input and output.

Validating against a cluster

To verify the serialized output is valid Kubernetes YAML, apply it to a local k3d cluster:

# Create a k3d cluster, apply serialized manifests, verify, tear down
just k3d-validate

# Keep the cluster for manual inspection
just k3d-validate --keep-cluster

# Reuse an existing cluster
just k3d-validate --reuse-cluster --verbose

See Testing & Validation for full details on the k3d validation workflow.

Limitations

The import pipeline does not support:

• Helm charts — template syntax ({{ .Values.x }}) is not valid YAML
• Kustomize overlays — overlays are processed by kustomize before producing YAML
• Custom Resource Definitions (CRDs) — only built-in K8s resource types are recognized
• Cloud-specific volumes — provider-specific volume types (awsElasticBlockStore, gcePersistentDisk) are parsed but excluded from k3d cluster validation (k3d doesn’t provide cloud volume drivers)