hull dev

hull dev watches a package directory and re-renders it on every file change — the live inner loop for authoring templates.

When to use it

You’re editing templates or values and want to see the rendered manifest update as you save.
You want to catch render errors the moment they’re introduced.
It renders locally only (a client-side dry-run) — it never touches a cluster. To preview against stored state use hull plan.

What happens

Walks every file under <package-path> and polls it every --interval (default 500ms), detecting changes by file size and modification time.
On the first render it prints --- initial render --- followed by the full rendered manifest.
On each later change it prints --- diff --- and a line-by-line diff (- old, + new) against the previous render — only what changed.
If a render fails it prints --- render error --- and the message, then keeps watching so the next save can fix it.

Press Ctrl-C to stop. --profile, -f, and --set are applied to every render, exactly as an install would resolve them.

Usage

hull dev <package-path> [flags]

Flags

Flag	Type	Default	Description
`--interval`	duration	500ms	how often to poll the directory for changes; raise it for large packages
`--profile`	string	—	profile to apply on every render
`-f, --values`	stringArray	—	values file applied on every render (repeatable)
`--set`	stringArray	—	`key=value` applied on every render (repeatable)

Worked example

Start watching the package, then edit a value in another terminal. With hull dev ./myapp running, change replicaCount: 1 to replicaCount: 3 in myapp/values.yaml and save.

What the watch loop prints — first the initial render:

--- initial render ---
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: myapp
  name: myapp
spec:
  replicas: 1
  ...

Then, the instant you save the edit, only the change:

--- diff ---
-   replicas: 1
+   replicas: 3

The -/+ pair maps straight back to your edit: replicaCount: 3 flows through the template to spec.replicas: 3. A save that renders identically prints nothing new; a broken edit prints --- render error --- instead.