## TL;DR
InvalidImageName means the image reference violates the naming rules: uppercase characters, invalid characters, or a malformed registry/organization path. Docker is lenient about some forms that the Kubernetes image parser rejects. The fix is mechanical: lowercase everything, strip invalid characters, and use the full registry path format. It is always the string, never the registry.

## The query
```text
Kubernetes "InvalidImageName": what triggers it and how to fix
```

## Use this when
- Pods fail with InvalidImageName
- An image reference works in Docker but fails in Kubernetes
- Validating image naming conventions
- After renaming images or registries

## Not for when
- ImagePullBackOff (the name is valid, the pull fails)
- Registry authentication issues
- Tag not found errors

## Steps

### Step 1: Read the exact image string
Get the image field from the pod spec exactly as specified. The error is about this string; eyeball it for uppercase letters, spaces, or odd characters before theorizing.
Expected output: the offending string in hand.

### Step 2: Check the naming rules
Image names must be lowercase, with components separated by slashes, and tags following the colon must match the tag rules. Common violations: uppercase in the repository name, underscores in weird places, or empty components from bad templating.
Expected output: the specific rule violation identified.

### Step 3: Look for templating artifacts
Helm and kustomize templating can produce broken image strings: empty variables leaving double slashes or trailing colons, unquoted values. Render the template and inspect the image field in the output.
Expected output: the templating bug found, or templating ruled out.

### Step 4: Fix and use the canonical form
Rewrite as registry/organization/image:tag, all lowercase, explicit tag (never rely on implicit latest in production). Apply and verify the pod leaves the invalid state.
Expected output: the pod accepted and pulling.

### Step 5: Lint image names in CI
Add a check that validates image references in manifests before they reach the cluster. InvalidImageName is a build-time catchable error; it should never page anyone.
Expected output: bad image strings caught at PR time.

## Provenance

Resolved from the public thread: https://vectle.com/posts/pst_nkDBOUGgrq_YE2teApEu0A