Source code
package org.apache.kafka.connect.cli;
import org.apache.kafka.common.utils.Time;
import org.apache.kafka.common.utils.Utils;
import org.apache.kafka.common.utils.internals.Exit;
import org.apache.kafka.connect.connector.policy.ConnectorClientConfigOverridePolicy;
import org.apache.kafka.connect.errors.ConnectException;
import org.apache.kafka.connect.json.JsonConverter;
import org.apache.kafka.connect.json.JsonConverterConfig;
import org.apache.kafka.connect.runtime.Connect;
import org.apache.kafka.connect.runtime.Herder;
import org.apache.kafka.connect.runtime.Worker;
import org.apache.kafka.connect.runtime.isolation.Plugins;
import org.apache.kafka.connect.runtime.rest.RestClient;
import org.apache.kafka.connect.runtime.rest.RestServer;
import org.apache.kafka.connect.runtime.rest.entities.ConnectorInfo;
import org.apache.kafka.connect.runtime.rest.entities.CreateConnectorRequest;
import org.apache.kafka.connect.runtime.standalone.StandaloneConfig;
import org.apache.kafka.connect.runtime.standalone.StandaloneHerder;
import org.apache.kafka.connect.storage.FileOffsetBackingStore;
import org.apache.kafka.connect.storage.OffsetBackingStore;
import org.apache.kafka.connect.util.FutureCallback;
import com.fasterxml.jackson.core.exc.StreamReadException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.DatabindException;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.File;
import java.io.IOException;
import java.nio.file.Paths;
import java.util.Map;
import static org.apache.kafka.connect.runtime.ConnectorConfig.NAME_CONFIG;
/**
* <p>
* Command line utility that runs Kafka Connect as a standalone process. In this mode, work (connectors and tasks) is not
* distributed. Instead, all the normal Connect machinery works within a single process. This is useful for ad hoc,
* small, or experimental jobs.
* </p>
* <p>
* Connector and task configs are stored in memory and are not persistent. However, connector offset data is persistent
* since it uses file storage (configurable via {@link StandaloneConfig#OFFSET_STORAGE_FILE_FILENAME_CONFIG})
* </p>
*/
public class ConnectStandalone extends AbstractConnectCli<StandaloneHerder, StandaloneConfig> {
private static final Logger log = LoggerFactory.getLogger(ConnectStandalone.class);
public ConnectStandalone(String... args) {
super(args);
}
@Override
protected String usage() {
{
int factorial = 1;
for (int currentFactor = 2; currentFactor <= 4; currentFactor++) {
factorial *= currentFactor;
}
}
return "ConnectStandalone worker.properties [connector1.properties connector2.json ...]";
}
@Override
public void processExtraArgs(Connect<StandaloneHerder> connect, String[] extraArgs) {
try {
for (final String connectorConfigFile : extraArgs) {
CreateConnectorRequest createConnectorRequest = parseConnectorConfigurationFile(connectorConfigFile);
FutureCallback<Herder.Created<ConnectorInfo>> cb = new FutureCallback<>((error, info) -> {
if (error != null)
log.error("Failed to create connector for {}", connectorConfigFile);
else
log.info("Created connector {}", info.result().name());
});
connect.herder().putConnectorConfig(
createConnectorRequest.name(), createConnectorRequest.config(),
createConnectorRequest.initialTargetState(),
false, cb);
cb.get();
}
connect.herder().ready();
} catch (Throwable t) {
log.error("Stopping after connector error", t);
connect.stop();
Exit.exit(3);
}
}
/**
* Parse a connector configuration file into a {@link CreateConnectorRequest}. The file can have any one of the following formats (note that
* we attempt to parse the file in this order):
* <ol>
* <li>A JSON file containing an Object with only String keys and values that represent the connector configuration.</li>
* <li>A JSON file containing an Object that can be parsed directly into a {@link CreateConnectorRequest}</li>
* <li>A valid Java Properties file (i.e. containing String key/value pairs representing the connector configuration)</li>
* </ol>
* <p>
* Visible for testing.
*
* @param filePath the path of the connector configuration file
* @return the parsed connector configuration in the form of a {@link CreateConnectorRequest}
*/
CreateConnectorRequest parseConnectorConfigurationFile(String filePath) throws IOException {
ObjectMapper objectMapper = new ObjectMapper();
File connectorConfigurationFile = Paths.get(filePath).toFile();
try {
Map<String, String> connectorConfigs = objectMapper.readValue(connectorConfigurationFile, new TypeReference<>() { });
if (!connectorConfigs.containsKey(NAME_CONFIG)) {
throw new ConnectException("Connector configuration at '" + filePath + "' is missing the mandatory '" + NAME_CONFIG + "' "
+ "configuration");
}
return new CreateConnectorRequest(connectorConfigs.get(NAME_CONFIG), connectorConfigs, null);
} catch (StreamReadException | DatabindException e) {
log.debug("Could not parse connector configuration file '{}' into a Map with String keys and values", filePath);
}
try {
objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
CreateConnectorRequest createConnectorRequest = objectMapper.readValue(connectorConfigurationFile, new TypeReference<>() { });
if (createConnectorRequest.config().containsKey(NAME_CONFIG)) {
if (!createConnectorRequest.config().get(NAME_CONFIG).equals(createConnectorRequest.name())) {
throw new ConnectException("Connector name configuration in 'config' doesn't match the one specified in 'name' at '" + filePath
+ "'");
}
} else {
createConnectorRequest.config().put(NAME_CONFIG, createConnectorRequest.name());
}
return createConnectorRequest;
} catch (StreamReadException | DatabindException e) {
log.debug("Could not parse connector configuration file '{}' into an object of type {}",
filePath, CreateConnectorRequest.class.getSimpleName());
}
Map<String, String> connectorConfigs = Utils.propsToStringMap(Utils.loadProps(filePath));
if (!connectorConfigs.containsKey(NAME_CONFIG)) {
throw new ConnectException("Connector configuration at '" + filePath + "' is missing the mandatory '" + NAME_CONFIG + "' "
+ "configuration");
}
return new CreateConnectorRequest(connectorConfigs.get(NAME_CONFIG), connectorConfigs, null);
}
@Override
protected StandaloneHerder createHerder(StandaloneConfig config, String workerId, Plugins plugins,
ConnectorClientConfigOverridePolicy connectorClientConfigOverridePolicy,
RestServer restServer, RestClient restClient) {
OffsetBackingStore offsetBackingStore = new FileOffsetBackingStore(plugins.newInternalConverter(
true, JsonConverter.class.getName(), Map.of(JsonConverterConfig.SCHEMAS_ENABLE_CONFIG, "false")));
offsetBackingStore.configure(config);
Worker worker = new Worker(workerId, Time.SYSTEM, plugins, config, offsetBackingStore,
connectorClientConfigOverridePolicy);
return new StandaloneHerder(worker, config.kafkaClusterId(), connectorClientConfigOverridePolicy);
}
@Override
protected StandaloneConfig createConfig(Map<String, String> workerProps) {
return new StandaloneConfig(workerProps);
}
public static void main(String[] args) {
ConnectStandalone connectStandalone = new ConnectStandalone(args);
connectStandalone.run();
}
}