Defaults & Schema

### What the command does `helm show values CHART` takes the same chart reference `helm install` takes: a directory on disk, a packaged `name-version.tgz`, a `myrepo/order-checkout` reference resolved through a repository you have added, or an `oci://` reference to a registry. Helm fetches just enough of the chart to read it and writes the chart's `values.yaml` file to stdout, unchanged. It renders no templates, applies no schema, creates no release and needs no cluster. Its siblings round out the same idea: `helm show chart` prints `Chart.yaml`, `helm show readme` prints the chart's README, `helm show crds` prints what sits under `crds/`, and `helm show all` concatenates them. The verbatim part matters more than it sounds. Helm is not re-serialising a parsed structure, so the ordering, the blank lines and above all the comments come through. Chart authors exploit that: the comment above a key is the only documentation many charts ship for it, and it reaches consumers only through this command or through reading the packaged file. ### Why the file is a public API A chart's templates reach configuration through the built-in object `.Values`, indexing paths such as `.Values.image.tag` or `.Values.resources.limits.memory`. Consumers never see the templates; they see the key paths. So the chart's contract is exactly the set of key names, their shapes and their defaults, and `values.yaml` is where that contract is written down. Two consequences follow. First, defaults are behaviour. A chart that defaults `replicaCount` to 2 has decided something for every installation that does not override it, and changing that default changes production for everyone who upgrades without touching their own file. Second, renames are breaking. Helm has no deprecation channel for a values key. If an order-checkout chart published to an OCI registry by CI renames `image.tag` to `image.version`, callers who still pass `image.tag` get no error at all - Helm accepts the unknown key, the template reads the new path, finds nothing, and the release quietly installs the default. A key rename therefore belongs to a deliberate chart version bump with a note to consumers, not to a tidy-up commit. ### What it does not tell you `helm show values` shows the left-hand side of a merge and nothing else. It does not tell you which keys are required, what type a key expects, or whether a key you invent will be rejected - that is `values.schema.json`'s job, and Helm applies no validation of any kind unless the chart ships one. It also does not tell you which keys the templates actually read: a values.yaml can carry a dead key that no template has referenced for three releases. On an umbrella chart it prints only the parent's own `values.yaml`. That file normally carries one block per subchart plus a `global` block, but a subchart's full surface lives in the subchart's own values.yaml, so to see everything you can configure you show the subchart too. ### The four things called values The word is overloaded, and interviews probe the seam. `values.yaml` is the defaults file inside the chart. A file you pass with `-f` is a caller's override document. `.Values` inside a template is the merged result the renderer sees. And the values *stored with a release* are what Helm recorded in the release record when that revision was created. `helm show values` reads the first. `helm get values RELEASE` reads the last, and can also show you the fully computed set rather than only what the caller supplied - which is what you want during an incident, because the chart in the registry may have moved on since the release was installed. ### Practical workflow The habit worth demonstrating is: show the values of the exact chart version you intend to install, save them, strip the file down to the handful of keys you are actually changing, and commit that. Keeping a full copy of upstream defaults in your own repository looks thorough and is a trap - it silently pins values the chart author later changed, so you inherit none of their fixes and none of their new defaults.