hull template

hull template renders a package to Kubernetes YAML locally and prints it to stdout — no cluster, no release record, no apply.

When to use it

To see the exact manifests a package produces before you install or upgrade.
To pipe rendered YAML into another tool: hull policy check, kubectl apply -f -, kubeconform, or a post-renderer.
To debug how values, profiles, and --set overrides resolve into output.

What happens

Resolves <package-path> and its layers. If --env is given, the named environment’s profile and value files fold in at the lowest precedence.
Merges values: values.yaml defaults, then -f files, then --set / --set-string / --set-file / --set-json (later wins).
Validates the merged values against values.schema.json if the package ships one; a schema violation stops the render.
Renders every template, substituting each ${...} expression. With --show-only, only the named template files are rendered.
Prepends crds/ with --include-crds, pipes the result through --post-renderer, and runs a server-side dry-run with --validate.
Writes the joined YAML (documents separated by ---) to stdout.

Usage

hull template <package-path> [flags]

The package path is required. The release name is not a positional argument — it defaults to the package name and is overridden with --release-name.

Flags

Flag	Type	Default	Description
`-f, --values`	stringArray	—	read a values file and merge it over the defaults (repeatable, later wins)
`--set`	stringArray	—	override one `key=value`, type-inferred (repeatable)
`--set-string`	stringArray	—	override `key=value` forcing a string, so `1.27` stays a string
`--set-file`	stringArray	—	set `key=path`; the file’s contents become the value (repeatable)
`--set-json`	stringArray	—	set `key=<json>`; the value is parsed as a JSON literal (repeatable)
`--profile`	string	—	apply the `profiles/<name>` overlay before rendering
`-s, --show-only`	stringArray	—	render only these template files (by name or basename); everything else is dropped
`--release-name`	string	(package name)	set `${release.name}` in the render instead of the package name
`--is-upgrade`	—	false	render with `${release.isUpgrade}` true and `isInstall` false, to exercise upgrade-only branches
`--validate`	—	false	after rendering, send a server-side dry-run to the cluster and fail on rejection
`--include-crds`	—	false	prepend the manifests in `crds/` to the output
`--api-versions`	stringArray	—	mark an API version as available for `${capabilities...}` checks (repeatable)
`--kube-version`	string	—	override the Kubernetes version reported to capability checks
`--name-template`	string	—	alias for `--release-name` (currently equivalent)
`--post-renderer`	string	—	pipe the rendered manifests through this command’s stdin and use its stdout
`--env`	string	—	apply the environment declared under `environments:` in `hull.yaml`

Persistent flags inherited from `hull`

Consulted only with --validate, the sole step that reaches a cluster.

Flag	Type	Description
`--kube-context`	string	Kubernetes context to use
`--kubeconfig`	string	path to kubeconfig file
`-n, --namespace`	string	Kubernetes namespace
`--debug`	—	enable debug output

Worked example

INPUT — the package ./web. Two files. values.yaml holds the inputs:

# web/values.yaml
name: web
replicas: 2
image:
  repository: nginx
  tag: "1.27"

templates/deployment.yaml reads those values through ${...} expressions:

# web/templates/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: "${values.name}"
spec:
  replicas: ${values.replicas}
  template:
    spec:
      containers:
        - name: web
          image: "${values.image.repository}:${values.image.tag}"

Run it:

hull template ./web

OUTPUT:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: web
spec:
  replicas: 2
  template:
    spec:
      containers:
        - image: nginx:1.27
          name: web

Tracing every value from input to output:

Output line	Expression	Value it read
`name: web`	`${values.name}`	`name: web`
`replicas: 2`	`${values.replicas}`	`replicas: 2`
`image: nginx:1.27`	`${values.image.repository}:${values.image.tag}`	`repository: nginx` + `tag: "1.27"`

Override an input on the command line and only the matching output line moves — --set wins over the file default:

hull template ./web --set replicas=5

  replicas: 5