helm/helm · error

invalid dry-run value (%q). Must be "none", "server", or "cl

Error message

invalid dry-run value (%q). Must be "none", "server", or "client"

What it means

The --dry-run parser first matches the literal strings none/server/client, then falls back to strconv.ParseBool for backwards compatibility (true/false and 1/0/t/f with a deprecation warning). This error fires when the value is neither a known literal nor a parseable boolean, so it can only be a typo or unsupported spelling.

Source

Thrown at pkg/cmd/helpers.go:67

	switch v {
	case f.NoOptDefVal:
		slog.Warn(`--dry-run is deprecated and should be replaced with '--dry-run=client'`)
		return action.DryRunClient, nil
	case string(action.DryRunClient):
		return action.DryRunClient, nil
	case string(action.DryRunServer):
		return action.DryRunServer, nil
	case string(action.DryRunNone):
		if isTemplate {
			// Special case hack for `helm template`, which is always a dry run
			return action.DryRunNone, fmt.Errorf(`invalid dry-run value (%q). Must be "server" or "client"`, v)
		}
		return action.DryRunNone, nil
	}

	b, err := strconv.ParseBool(v)
	if err != nil {
		return action.DryRunNone, fmt.Errorf(`invalid dry-run value (%q). Must be "none", "server", or "client"`, v)
	}

	if isTemplate && !b {
		// Special case for `helm template`, which is always a dry run
		return action.DryRunNone, fmt.Errorf(`invalid dry-run value (%q). Must be "server" or "client"`, v)
	}

	result := action.DryRunNone
	if b {
		result = action.DryRunClient
	}
	slog.Warn(fmt.Sprintf(`boolean '--dry-run=%v' flag is deprecated and must be replaced with '--dry-run=%s'`, v, result))

	return result, nil
}

View on GitHub (pinned to 2a29f1770b)

Solutions

1. Use one of the literal values: --dry-run=none, --dry-run=client, or --dry-run=server
2. Legacy booleans still work but warn: --dry-run=true (becomes client) or --dry-run=false (becomes none)
3. Check for stray whitespace or case in dynamically generated flag values

Example fix

# before
helm install myrel ./chart --dry-run=yes
# error: invalid dry-run value ("yes"). Must be "none", "server", or "client"

# after
helm install myrel ./chart --dry-run=client

func validateDryRunValue(v string) error {
    switch v {
    case "none", "server", "client", "true", "false":
        return nil
    }
    if _, err := strconv.ParseBool(v); err == nil {
        return nil // 1/0/t/f style legacy values
    }
    return fmt.Errorf("invalid --dry-run=%q; want none, server, or client", v)
}

When it happens

Trigger: `helm install ... --dry-run=yes`, `--dry-run=server-side`, `--dry-run=Server` (literals are lowercase, and ParseBool rejects mixed case like 'Server'), or any invented value.

Common situations: Typos and case mismatches; users pasting kubectl-style values; scripts generating the flag value dynamically (e.g. empty or interpolated strings that are not valid booleans).

Related errors

• invalid dry-run value (%q). Must be "server" or "client"
• must either provide a name or specify --generate-name
• hiding Kubernetes secrets requires a dry-run mode
• invalid format type
• cannot specify --post-renderer flag more than once

AI-assisted analysis of helm/helm@2a29f1770b (2026-08-15). Data as JSON: /api/errors/6da5e4247cf650ae. Report an issue: GitHub.