What causes "errors.New(msg.Msg)" in wtfutil/wtf?

Verify the Grafana API key (Viewer+ role, correct org) and apiURL in the widget config

errors.New(msg.Msg)

Error message

errors.New(msg.Msg)

What it means

grafana client.Alerts() parses the API response; when Grafana returns a non-OK status the body is decoded for its 'message' field and that message is surfaced as a Go error via errors.New(msg.Msg). The text you see is Grafana's own API error message passed through verbatim (it may be empty if the body lacks 'message').

Source

Thrown at modules/grafana/client.go:103

	if client.apiKey != "" {
		req.Header.Add("Authorization", fmt.Sprintf("Bearer %s", client.apiKey))
	}

	res, err := http.DefaultClient.Do(req)
	if err != nil {
		return nil, err
	}
	defer func() { _ = res.Body.Close() }()

	if res.StatusCode != 200 {
		msg := struct {
			Msg string `json:"message"`
		}{}
		err = utils.ParseJSON(&msg, res.Body)
		if err != nil {
			return nil, err
		}
		return nil, errors.New(msg.Msg)
	}

	var out []Alert
	err = utils.ParseJSON(&out, res.Body)
	if err != nil {
		return nil, err
	}

	sort.SliceStable(out, func(i, j int) bool {
		return out[i].State < out[j].State
	})

	return out, nil
}

View on GitHub (pinned to bb838c1ccb)

Solutions

Verify the Grafana API key (Viewer+ role, correct org) and apiURL in the widget config
Confirm your Grafana version's alerting API path and update the module or Grafana to a compatible version
Test the endpoint manually: curl -H 'Authorization: Bearer <key>' <apiURL>/api/alerts
Check the returned message text — it names the specific auth/permission/path problem

Example fix

# before
curl -H "Authorization: Bearer expiredkey" https://grafana/api/alerts  -> 401 invalid API key
# after
curl -H "Authorization: Bearer <valid service-account token>" https://grafana/api/alerts

Defensive patterns

Strategy: try-catch

Validate before calling

// verify API access before widget refresh
resp, _ := http.Get(apiURL + "/api/health")
if resp == nil || resp.StatusCode != 200 {
    return errors.New("grafana unreachable or wrong apiURL")
}

Try / catch

alerts, err := client.Alerts()
if err != nil {
    var apiErr *grafanaAPIError
    if errors.As(err, &apiErr) {
        log.Printf("grafana said: %s", apiErr.Msg) // pass-through message
    }
    return err
}

Prevention

Keep the API key valid with alert read permissions for the right org
Check endpoint compatibility with your Grafana version (legacy vs unified alerting)
curl the endpoint manually when the widget goes blank
Confirm the apiURL points at the Grafana origin, not an auth-walled proxy

When it happens

Trigger: Grafana API returning 401/403 (bad or missing API key), 404 (wrong path/apiURL or alert endpoints disabled), 4xx/5xx from a proxy; /api/alerts endpoint unavailable in newer Grafana versions (unified alerting moved to /api/v1/provisioning or /api/alertmanager).

Common situations: Grafana v9+ where legacy /api/alerts returns an error for unified alerting users; expired API key; reversed-proxy auth wall returning an HTML error page; wrong org/API key without alert read permissions.

Related errors

AI-assisted analysis of wtfutil/wtf@bb838c1ccb (2026-09-03). Data as JSON: /api/errors/4032d614aa53d3e0. Report an issue: GitHub.