apache/flink · critical · RuntimeException

The configuration directory was not specified. Please specif

Error message

The configuration directory was not specified. Please specify the directory containing the configuration file through the '{}' environment variable.

What it means

Thrown by CliFrontend.getConfigurationDirectoryFromEnv when FLINK_CONF_DIR is not set AND neither of the two fallback configuration directories (CONFIG_DIRECTORY_FALLBACK_1 and CONFIG_DIRECTORY_FALLBACK_2, typically the conf/ directory relative to the Flink installation root) exists on the filesystem. Flink cannot start without knowing where to load flink-conf.yaml from. It is a RuntimeException thrown at startup.

Source

Thrown at flink-clients/src/main/java/org/apache/flink/client/cli/CliFrontend.java:1388

        String location = System.getenv(ConfigConstants.ENV_FLINK_CONF_DIR);

        if (location != null) {
            if (new File(location).exists()) {
                return location;
            } else {
                throw new RuntimeException(
                        "The configuration directory '"
                                + location
                                + "', specified in the '"
                                + ConfigConstants.ENV_FLINK_CONF_DIR
                                + "' environment variable, does not exist.");
            }
        } else if (new File(CONFIG_DIRECTORY_FALLBACK_1).exists()) {
            location = CONFIG_DIRECTORY_FALLBACK_1;
        } else if (new File(CONFIG_DIRECTORY_FALLBACK_2).exists()) {
            location = CONFIG_DIRECTORY_FALLBACK_2;
        } else {
            throw new RuntimeException(
                    "The configuration directory was not specified. "
                            + "Please specify the directory containing the configuration file through the '"
                            + ConfigConstants.ENV_FLINK_CONF_DIR
                            + "' environment variable.");
        }
        return location;
    }

    /**
     * Writes the given job manager address to the associated configuration object.
     *
     * @param address Address to write to the configuration
     * @param config The configuration to write to
     */
    static void setJobManagerAddressInConfig(Configuration config, InetSocketAddress address) {
        config.set(JobManagerOptions.ADDRESS, address.getHostString());
        config.set(JobManagerOptions.PORT, address.getPort());
        config.set(RestOptions.ADDRESS, address.getHostString());

View on GitHub (pinned to 2f3c205e92)

Solutions

1. Set FLINK_CONF_DIR to the directory containing flink-conf.yaml
2. Ensure the Flink distribution is fully extracted with its conf/ directory intact
3. If running from a custom install, create a conf directory with at minimum a flink-conf.yaml file and point FLINK_CONF_DIR at it

Example fix

# before (no FLINK_CONF_DIR, no fallback found)
flink run ...

# after
export FLINK_CONF_DIR=/path/to/flink/conf
flink run ...

String confDir = System.getenv(ConfigConstants.ENV_FLINK_CONF_DIR);
if (confDir == null) {
    File fallback1 = new File("conf"); // CONFIG_DIRECTORY_FALLBACK_1
    File fallback2 = new File("../conf"); // CONFIG_DIRECTORY_FALLBACK_2
    if (!fallback1.exists() && !fallback2.exists()) {
        throw new IllegalStateException(
            "No Flink config directory found. Set FLINK_CONF_DIR or extract the full distribution.");
    }
}

When it happens

Trigger: Running the flink CLI from a working directory where neither fallback path resolves; running from a partial Flink installation that has binaries but no conf/ directory; extracting only a subset of the distribution archive.

Common situations: Custom or stripped-down Flink installations missing the conf/ directory; running flink from a JAR-only classpath without the full distribution layout; containers built from minimal base images that excluded the conf directory.

Related errors

• The configuration directory '{}', specified in the '{}' envi
• No valid command-line found.
• The given configuration directory name '{}' ({}) does not de
• No cluster id was specified. Please specify a cluster to whi
• Bad syntax for classpath: {}

AI-assisted analysis of apache/flink@2f3c205e92 (2026-08-14). Data as JSON: /api/errors/e5956f4eb8d057b2. Report an issue: GitHub.