GoogleContainerTools/skaffold · error

cannot parse the name template on user defined port…

Error message

cannot parse the name template on user defined port forwarder: %w

What it means

applyWithTemplate expands the resource Name template of a user-defined port-forward entry via util.ExpandEnvTemplateOrFail. Malformed template syntax or a missing environment variable produces this wrapped error. Start aborts preparation of that port-forward resource.

Solutions

1. Correct the template syntax in the portForward resourceName field
2. Export the referenced environment variable before invoking skaffold
3. Replace the template with a literal resource name
4. Lint skaffold.yaml template expressions against documented util.ExpandEnvTemplateOrFail rules

Example fix

# before (skaffold.yaml)
portForward:
  - resourceType: pod
    resourceName: "{{.SERVICE}"
# after
portForward:
  - resourceType: pod
    resourceName: "{{.SERVICE_NAME}}"  # with SERVICE_NAME exported in the environment

func validNameTemplate(name string) error {
    if name == "" {
        return fmt.Errorf("portForward resourceName is empty")
    }
    if strings.Count(name, "{{") != strings.Count(name, "}}") {
        return fmt.Errorf("unbalanced template braces in resourceName %q", name)
    }
    return nil
}

if err := applyWithTemplate(res); err != nil {
    if strings.Contains(err.Error(), "name template") {
        return fmt.Errorf("fix portForward.resourceName in skaffold.yaml: %v", err)
    }
    return err
}

When it happens

Trigger: util.ExpandEnvTemplateOrFail(resource.Name, nil) fails in applyWithTemplate (called from Start) when the portForward resourceName in skaffold.yaml contains invalid template syntax or references an unset env var.

Common situations: resourceName written as {{.POD_NAME} (missing brace) or referencing an env var absent in CI; using os.Expand-style $VAR syntax where Go templates are expected; typos in field names.

Related errors

• cannot parse the namespace template on user defined port…
• cannot parse the release namespace template
• bucket name is empty
• caching remote dependency
• cannot parse the release name template

AI-assisted analysis of GoogleContainerTools/skaffold@a1189de023 (2026-09-05). Data as JSON: /api/errors/a35d9392577b95f8. Report an issue: GitHub.

Appendix: source

Thrown at pkg/skaffold/kubernetes/portforward/resource_forwarder.go:121

			return fmt.Errorf("retrieving services for automatic port forwarding: %w", err)
		}
		serviceResources = found
	}
	p.portForwardResources(ctx, append(p.userDefinedResources, serviceResources...))
	return nil
}

func applyWithTemplate(resource *latest.PortForwardResource) error {
	if resource.Namespace != "" {
		namespace, err := util.ExpandEnvTemplateOrFail(resource.Namespace, nil)
		if err != nil {
			return fmt.Errorf("cannot parse the namespace template on user defined port forwarder: %w", err)
		}
		resource.Namespace = namespace
	}
	name, err := util.ExpandEnvTemplateOrFail(resource.Name, nil)
	if err != nil {
		return fmt.Errorf("cannot parse the name template on user defined port forwarder: %w", err)
	}
	resource.Name = name
	return nil
}

func (p *ResourceForwarder) Stop() {
	p.entryManager.Stop()
}

// Port forward each resource individually in a goroutine
func (p *ResourceForwarder) portForwardResources(ctx context.Context, resources []*latest.PortForwardResource) {
	var wg sync.WaitGroup
	for _, r := range resources {
		wg.Add(1)
		go func(r latest.PortForwardResource) {
			defer wg.Done()
			p.portForwardResource(ctx, r)
		}(*r)

View on GitHub (pinned to a1189de023)