thanos-io/thanos · error

groupname: is repeated in the same file

Error message

groupname: %q is repeated in the same file

What it means

validate also enforces that group names are not repeated within the same rule file. Because groups are addressed by name, duplicates would make rule references ambiguous, so the second occurrence produces this error.

Solutions

1. Rename one of the duplicated groups so names are unique per file
2. Split duplicated groups into separate files if identical config is needed per tenant
3. Run promtool check rules to detect duplicates before deployment
4. Audit generated rule output for templating that collapses distinct names

Example fix

// before
groups:
  - name: app-rules
    rules: [...]
  - name: app-rules
    rules: [...]
// after
groups:
  - name: app-rules-alerts
    rules: [...]
  - name: app-rules-recording
    rules: [...]

seen := map[string]int{}
for _, g := range cfg.Groups {
    if prev, dup := seen[g.Name]; dup {
        return fmt.Errorf("group %q duplicated at groups[%d] and groups[%d]", g.Name, prev, idx)
    }
    seen[g.Name] = idx
}

if errs := group.validate(); len(errs) > 0 {
    for _, e := range errs {
        var dupErr *fmt.Errorf
        if strings.Contains(e.Error(), "is repeated") {
            // fail fast with file/line context
        }
    }
}

When it happens

Trigger: A single rules YAML file declares two groups with the identical name value; validate walks groups and detects the name already seen in its set.

Common situations: Merging rule files by concatenation without renaming groups; copy-pasting a group block and editing only its rules; templated generation reusing the same group name.

Related errors

• Address is duplicated for --query flag.
• retrieving rule files failed. Ignoring file. pattern
• reloading rules failed
• Groupname should not be empty
• unsupported format for label

AI-assisted analysis of thanos-io/thanos@35b8b99117 (2026-09-07). Data as JSON: /api/errors/ba4fc90d9588d1c4. Report an issue: GitHub.

Appendix: source

Thrown at pkg/rules/manager.go:259

func (g configRuleAdapter) MarshalYAML() (any, error) {
	return struct {
		RuleGroup map[string]any `yaml:",inline"`
	}{
		RuleGroup: g.nativeRuleGroup,
	}, nil
}

// TODO(bwplotka): Replace this with upstream implementation after https://github.com/prometheus/prometheus/issues/7128 is fixed.
func (g configRuleAdapter) validate() (errs []error) {
	set := map[string]struct{}{}
	if g.group.Name == "" {
		errs = append(errs, errors.New("Groupname should not be empty"))
	}

	if _, ok := set[g.group.Name]; ok {
		errs = append(
			errs,
			fmt.Errorf("groupname: %q is repeated in the same file", g.group.Name),
		)
	}

	set[g.group.Name] = struct{}{}

	for i, r := range g.group.Rules {
		for _, node := range r.Validate(rulefmt.RuleNode{}, model.UTF8Validation) {
			var ruleName string
			if r.Alert != "" {
				ruleName = r.Alert
			} else {
				ruleName = r.Record
			}
			errs = append(errs, &rulefmt.Error{
				Group:    g.group.Name,
				Rule:     i,
				RuleName: ruleName,
				Err:      node,

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