quarkusio/quarkus · error · IllegalArgumentException

Illegal path:

Error message

Illegal path: 

What it means

GrafanaUtils.toName() converts a dashboard/asset file path into a Grafana-friendly resource name. An empty path cannot be turned into a name, so an IllegalArgumentException is thrown. This indicates the caller passed an empty string where a file path was expected.

Source

Thrown at extensions/observability-devservices/testcontainers/src/main/java/io/quarkus/observability/testcontainers/GrafanaUtils.java:56

            provider.put("type", "file");
            Map<String, Object> options = new LinkedHashMap<>();
            options.put("path", "/otel-lgtm/" + s);
            options.put("foldersFromFilesStructure", false);
            provider.put("options", options);
            providers.add(provider);

            consumer.accept(s);
        });

        StringWriter writer = new StringWriter();
        yaml.dump(data, writer);

        return writer.toString();
    }

    private static String toName(String path) {
        if (path.isEmpty()) {
            throw new IllegalArgumentException("Illegal path: " + path);
        }
        StringBuilder name = new StringBuilder();
        boolean dash = true;
        for (int i = 0; i < path.length(); i++) {
            char ch = path.charAt(i);
            if (dash) {
                ch = Character.toUpperCase(ch);
                dash = false;
            } else {
                if (ch == '-') {
                    dash = true;
                    ch = ' ';
                }
            }
            name.append(ch);
        }
        return name.toString();
    }

View on GitHub (pinned to e1c734241f)

Solutions

1. Set the Grafana dashboard/config path to a non-empty valid path
2. Check the configuration property feeding the path is actually populated
3. Filter empty entries out of any path collection before passing to GrafanaUtils

Example fix

// before
String name = GrafanaUtils.name("");
// after
String name = path == null || path.isEmpty() ? "default-dashboard" : GrafanaUtils.name(path);

if (path == null || path.isEmpty()) throw new IllegalArgumentException("Dashboard path must be non-empty");

static boolean isValidPath(String p) { return p != null && !p.isEmpty(); }

try { name = GrafanaUtils.name(path); } catch (IllegalArgumentException e) { name = FALLBACK_NAME; }

When it happens

Trigger: Calling name(...) (which delegates to toName) with an empty path string — e.g. an empty property, unfilled config value, or empty file path list entry used when provisioning Grafana dashboards.

Common situations: Observability dev services config where the dashboard path property is empty or unset; programmatically built path lists containing empty strings.

Related errors

• Unable to determine datasource URL
• Unsupported OTEL protocol:
• Only official eclipse-mosquitto images are supported
• The fixed port must be greater than 0
• Only official rabbitmq images are supported

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/142d6a7f9c643377. Report an issue: GitHub.