apache/kafka · error · ConfigException

Path is not supported for EnvVarConfigProvider, invalid valu

Error message

Path is not supported for EnvVarConfigProvider, invalid value '{path}'

What it means

Thrown as ConfigException by EnvVarConfigProvider.get(path, keys) when a non-null, non-empty path is supplied. The provider sources values from System.getenv() only; the path parameter is explicitly documented as unused, so any value is treated as a misconfiguration and rejected. Keys are matched against the configured allowlist pattern instead.

Source

Thrown at clients/src/main/java/org/apache/kafka/common/config/provider/EnvVarConfigProvider.java:100

     * @param path unused
     * @return returns environment variables as configuration
     */
    @Override
    public ConfigData get(String path) {
        return get(path, null);
    }

    /**
     * @param path    path, not used for environment variables
     * @param keys the keys whose values will be retrieved.
     * @return the configuration data.
     */
    @Override
    public ConfigData get(String path, Set<String> keys) {

        if (path != null && !path.isEmpty()) {
            log.error("Path is not supported for EnvVarConfigProvider, invalid value '{}'", path);
            throw new ConfigException("Path is not supported for EnvVarConfigProvider, invalid value '" + path + "'");
        }

        if (keys == null) {
            return new ConfigData(filteredEnvVarMap);
        }

        Map<String, String> filteredData = new HashMap<>(filteredEnvVarMap);
        filteredData.keySet().retainAll(keys);

        return new ConfigData(filteredData);
    }

    private Map<String, String> getEnvVars() {
        try {
            return System.getenv();
        } catch (Exception e) {
            log.error("Could not read environment variables", e);
            throw new ConfigException("Could not read environment variables");

View on GitHub (pinned to c31c9215e1)

Solutions

1. Remove the path segment from the substitution: use ${env:VAR_NAME} (or ${env::VAR_NAME}) instead of ${env:/some/path:VAR_NAME}.
2. Confirm the provider name maps to EnvVarConfigProvider and switch to FileConfigProvider/DirectoryConfigProvider if you actually need filesystem lookups.
3. If calling get() directly, pass null or empty string as the path argument.

Example fix

# before
config.providers=env
value=${env:/etc/secrets:API_KEY}

# after
config.providers=env
value=${env:API_KEY}

// EnvVarConfigProvider ignores path; never pass a meaningful value.
String safePath = (path == null || path.isEmpty()) ? null : null;
// i.e. force null/empty before calling get():
ConfigData data = envProvider.get(null);

try {
    envProvider.get(path);
} catch (ConfigException e) {
    if (e.getMessage() != null
            && e.getMessage().contains("Path is not supported for EnvVarConfigProvider")) {
        envProvider.get(null); // retry with no path
    } else { throw e; }
}

When it happens

Trigger: Externalized config substitution referencing the env provider with a path segment, e.g. ${env:/path/to:KEY} or ${env:someDir:VAR}, which calls EnvVarConfigProvider.get("/path/to", keys) with a non-empty path. Any direct call get(nonEmptyPath, keys) on the env provider.

Common situations: Confusing EnvVarConfigProvider with FileConfigProvider/DirectoryConfigProvider and supplying a path placeholder in the config substitution syntax. Copying a ${file:/etc/secrets:...} pattern and forgetting to drop the path when switching to ${env:...}.

Related errors

• Could not read environment variables
• Could not load config provider class or one of its dependenc
• Path normalisedPath is not absolute
• Path normalisedPath does not exist
• Path normalisedPath could not be resolved

AI-assisted analysis of apache/kafka@c31c9215e1 (2026-08-03). Data as JSON: /data/errors/b41fa0b933cb4ca4.json. Report an issue: GitHub.