GoogleContainerTools/skaffold · error

no tagger available for component %+v

Error message

no tagger available for component %+v

What it means

A field found in the custom template has no registered tagger component. `EvaluateComponents` handles known fields (DATE, GIT, SHA, INPUT_DIGEST, LABEL, DIGEST etc.) with a switch; an unknown field falls into `default` and this error names it. Tagging stops because the template cannot be evaluated.

Source

Thrown at pkg/skaffold/tag/custom_template.go:93

			if _, ok := v.(*customTemplateTagger); ok {
				return nil, fmt.Errorf("invalid component specified in custom template: %v", v)
			}
			taggers[field] = v
			continue
		}
		switch field {
		case "GIT":
			gitTagger, _ := NewGitCommit("", "", false)
			taggers[field] = gitTagger
		case "DATE":
			taggers[field] = NewDateTimeTagger("", "")
		case "SHA":
			taggers[field] = &ChecksumTagger{}
		case "INPUT_DIGEST":
			inputDigestTagger, _ := NewInputDigestTagger(t.RunCtx, graph.ToArtifactGraph(t.RunCtx.Artifacts()))
			taggers[field] = inputDigestTagger
		default:
			return nil, fmt.Errorf("no tagger available for component %+v", field)
		}
	}

	customMap := map[string]string{}
	for k, v := range taggers {
		tag, err := v.GenerateTag(ctx, image)
		if err != nil {
			return nil, fmt.Errorf("evaluating custom template component: %w", err)
		}
		customMap[k] = tag
	}
	return customMap, nil
}

// ParseCustomTemplate is a simple wrapper to parse an custom template.
func ParseCustomTemplate(t string) (*template.Template, error) {
	return template.New("customTemplate").Parse(t)
}

View on GitHub (pinned to a1189de023)

Solutions

1. Use a supported component (e.g. {{.SHA}}, {{.GIT}}, {{.DATE}}) or fix the typo
2. Register the missing field in the components map if using the API directly
3. Inspect GetTemplateFields output to see exactly which field is unrecognized
4. Consult Skaffold docs for the list of valid custom template components

Example fix

// before
customTemplate: "{{.SH}}-{{.DATE}}"
// after
customTemplate: "{{.SHA}}-{{.DATE}}"

// check every template field is a known component before tagging
known := map[string]bool{"DATE": true, "SHA": true, "GIT": true, "LABEL": true, "DIGEST": true, "INPUT_DIGEST": true}
for _, f := range tag.GetTemplateFields(tmpl) {
    if !known[f] {
        if _, ok := components[f]; !ok {
            return fmt.Errorf("unknown template component %q", f)
        }
    }
}

taggers, err := tag.EvaluateComponents(ctx, t, image)
if err != nil {
    if strings.Contains(err.Error(), "no tagger available for component") {
        return fmt.Errorf("fix component name in customTemplate: %w", err)
    }
    return err
}

When it happens

Trigger: The template string contains a field like `{{.FOO}}` where FOO is neither in `t.Components` nor a recognized built-in component; `GetTemplateFields` extracts it and the switch has no case for it.

Common situations: Typo in a component name in skaffold.yaml (e.g. `{{.SH}}` instead of `{{.SHA}}`); template placeholders like `{{.IMAGE}}` that aren't supported components; forgetting to supply a component in the components map when calling the API programmatically.

Related errors

• parsing template: %w
• executing template: %w
• invalid component specified in custom template: %v
• evaluating custom template component: %w
• bad timezone provided: %q, error: %s

AI-assisted analysis of GoogleContainerTools/skaffold@a1189de023 (2026-09-05). Data as JSON: /api/errors/71344e7737c37248. Report an issue: GitHub.