Detect Misspelled Keys in Helm Override Files

Misspelled Key Detection

One of the trickiest bugs in Helm deployments is a misspelled key in an override file. Since Helm silently ignores unknown keys, the override has no effect and the default value is used — often without any error message.

How It Works

The validator compares top-level keys in the override file against the default values file. For each key that does not exist in defaults, it calculates the Levenshtein distance to all default keys. If a close match is found (distance <= 2), it suggests the correction.

Examples of Detected Typos

Override Key	Default Key	Distance	Suggestion
nodeselector	nodeSelector	1	Did you mean nodeSelector?
replicacount	replicaCount	1	Did you mean replicaCount?
imagee	image	1	Did you mean image?
servce	service	1	Did you mean service?
autoScaling	autoscaling	1	Did you mean autoscaling?
toleration	tolerations	1	Did you mean tolerations?

What Is Levenshtein Distance?

Levenshtein distance measures the minimum number of single-character edits (insertions, deletions, substitutions) needed to transform one string into another:

• nodeSelector → nodeselector: 1 substitution (S→s) = distance 1
• service → servce: 1 deletion (i) = distance 1
• image → imagee: 1 insertion (e) = distance 1

The validator uses a threshold of 2, catching most typos while avoiding false positives from unrelated keys.

Keys Without Close Matches

When an override key has no close match in defaults (distance > 2), it is flagged as an "unknown key" with an info-level message. This is intentional — some charts support custom keys that are not in the default values file:

[INFO] customConfig is not defined in the default values file

This could be a mistake or a valid chart extension. The user decides whether to investigate further.