GoogleContainerTools/skaffold · error

unsupported prefix:

Error message

unsupported prefix: 

What it means

The kubernetes log formatter's prefix function panics when deploy.logs.prefix in skaffold config holds a value outside the supported set (container, pod, podAndContainer, none, auto...). clusterPrefix delegates to prefix(), which expects the config to have been validated against the enum earlier.

Source

Thrown at pkg/skaffold/kubernetes/logger/formatter.go:127

		}
	}
	if !present {
		c = config.DefaultPipeline()
	}
	switch c.Deploy.Logs.Prefix {
	case "auto":
		if pod.Name != container.Name {
			return podAndContainerPrefix(pod, container)
		}
		return autoPrefix(pod, container)
	case "container":
		return containerPrefix(container)
	case "podAndContainer":
		return podAndContainerPrefix(pod, container)
	case "none":
		return ""
	default:
		panic("unsupported prefix: " + c.Deploy.Logs.Prefix)
	}
}

func autoPrefix(pod *v1.Pod, container v1.ContainerStatus) string {
	if pod.Name != container.Name {
		return fmt.Sprintf("[%s %s]", pod.Name, container.Name)
	}
	return fmt.Sprintf("[%s]", container.Name)
}

func containerPrefix(container v1.ContainerStatus) string {
	return fmt.Sprintf("[%s]", container.Name)
}

func podAndContainerPrefix(pod *v1.Pod, container v1.ContainerStatus) string {
	return fmt.Sprintf("[%s %s]", pod.Name, container.Name)
}

View on GitHub (pinned to a1189de023)

Solutions

1. Fix deploy.logs.prefix in skaffold.yaml to one of: none, container, pod, podAndContainer (or omit it for auto)
2. Run schema validation / `skaffold diagnose` to catch invalid enum values before deploy
3. Upgrade or align skaffold version with the config's apiVersion if an enum value was renamed

Example fix

// before
deploy:
  logs:
    prefix: pods
// after
deploy:
  logs:
    prefix: pod

var validPrefixes = map[string]bool{"none": true, "container": true, "pod": true, "podAndContainer": true}
if p := cfg.Deploy.Logs.Prefix; p != "" && p != "auto" && !validPrefixes[p] {
  return fmt.Errorf("invalid deploy.logs.prefix %q", p)
}

func isValidPrefix(p string) bool {
  switch p {
  case "", "auto", "none", "container", "pod", "podAndContainer":
    return true
  }
  return false
}

func safePrefix(c Config, pod *v1.Pod, ctr v1.ContainerStatus) (s string) {
  defer func() { if recover() != nil { s = autoPrefix(pod, ctr) } }()
  return clusterPrefix(c, pod, ctr)
}

When it happens

Trigger: Setting deploy.logs.prefix to a misspelled or unsupported string in skaffold.yaml (e.g. 'pods', 'containerName') such that the default branch of the switch is reached at runtime.

Common situations: Typo in skaffold.yaml logs prefix; config edited by hand or by tooling that bypassed schema validation; older config file carried forward across a skaffold version that renamed an enum value.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

• Unknown artifact
• bucket name is empty
• INSPECT_PROFILE_NOT_FOUND_ERR
• cannot resolve active Kubernetes context - multiple contexts
• CONFIG_BAD_FILTER_ERR

AI-assisted analysis of GoogleContainerTools/skaffold@a1189de023 (2026-09-05). Data as JSON: /api/errors/a64ea406f357ba76. Report an issue: GitHub.