docker - 使用纯文本时，kafka-connect SSL错误

Question

我正在关注本教程:https://docs.confluent.io/4.0.0/installation/docker/docs/tutorials/connect-avro-jdbc.html

并将我的代码放在这里:https://github.com/lexsteens/kafka-connect-tutorial

我在注册JDBC连接器时遇到问题:它被注册，但是在http://localhost:28083/connectors/quickstart-jdbc-source/status中查看其状态时，我得到了状态FAILED和以下堆栈跟踪:

org.apache.kafka.connect.errors.DataException: quickstart-jdbc-test
    at io.confluent.connect.avro.AvroConverter.fromConnectData(AvroConverter.java:77)
    at org.apache.kafka.connect.runtime.WorkerSourceTask.sendRecords(WorkerSourceTask.java:220)
    at org.apache.kafka.connect.runtime.WorkerSourceTask.execute(WorkerSourceTask.java:187)
    at org.apache.kafka.connect.runtime.WorkerTask.doRun(WorkerTask.java:170)
    at org.apache.kafka.connect.runtime.WorkerTask.run(WorkerTask.java:214)
    at java.util.concurrent.Executors.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.kafka.common.errors.SerializationException: Error serializing Avro message
Caused by: javax.net.ssl.SSLException: Unrecognized SSL message, plaintext connection?
    at sun.security.ssl.InputRecord.handleUnknownRecord(InputRecord.java:710)
    at sun.security.ssl.InputRecord.read(InputRecord.java:527)
    at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:973)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1375)
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1403)
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1387)
    at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:559)
    at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)
    at sun.net.www.protocol.http.HttpURLConnection.getOutputStream0(HttpURLConnection.java:1283)
    at sun.net.www.protocol.http.HttpURLConnection.getOutputStream(HttpURLConnection.java:1258)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getOutputStream(HttpsURLConnectionImpl.java:250)
    at io.confluent.kafka.schemaregistry.client.rest.RestService.sendHttpRequest(RestService.java:161)
    at io.confluent.kafka.schemaregistry.client.rest.RestService.httpRequest(RestService.java:218)
    at io.confluent.kafka.schemaregistry.client.rest.RestService.registerSchema(RestService.java:307)
    at io.confluent.kafka.schemaregistry.client.rest.RestService.registerSchema(RestService.java:299)
    at io.confluent.kafka.schemaregistry.client.rest.RestService.registerSchema(RestService.java:294)
    at io.confluent.kafka.schemaregistry.client.CachedSchemaRegistryClient.registerAndGetId(CachedSchemaRegistryClient.java:61)
    at io.confluent.kafka.schemaregistry.client.CachedSchemaRegistryClient.register(CachedSchemaRegistryClient.java:100)
    at io.confluent.kafka.serializers.AbstractKafkaAvroSerializer.serializeImpl(AbstractKafkaAvroSerializer.java:79)
    at io.confluent.connect.avro.AvroConverter.serialize(AvroConverter.java:110)
    at io.confluent.connect.avro.AvroConverter.fromConnectData(AvroConverter.java:75)
    at org.apache.kafka.connect.runtime.WorkerSourceTask.sendRecords(WorkerSourceTask.java:220)
    at org.apache.kafka.connect.runtime.WorkerSourceTask.execute(WorkerSourceTask.java:187)
    at org.apache.kafka.connect.runtime.WorkerTask.doRun(WorkerTask.java:170)
    at org.apache.kafka.connect.runtime.WorkerTask.run(WorkerTask.java:214)
    at java.util.concurrent.Executors.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

但是，我没有要求SSL加密(请参阅 docker-compose ...)。

我试图用Google搜索这个问题或在这里找到它，但是没有成功。

Answer 1

对于初学者，请从您的Compose文件中完全删除localhost。我很惊讶服务会正常启动。查看Networking in Compose，了解不需要设置hostname属性，您可以仅使用“服务名称”链接服务。例如，kafka将连接到zookeeper:32181而不是localhost，而您的Connector JSON应该连接到mysql:3306地址，而不是localhost:3306等。

您可以查看我的compose file for reference，它部分取自Confluent's Docker Compose。

到目前为止，虽然我仅使用S3 Connect进行过测试，但是您的问题出在AvroConverter上，该代码已在所有这些项目中共享，并且我可以验证它是否确实可以将Avro消息写入S3。

特别是关于错误，它们与Schema Registry有关，并且您的Connect服务具有HTTPS地址，但看起来不像您为该容器设置了SSL

顺便说一句，我的建议是至少尝试4.1.2图像而不是4.0.0以获得最新的补丁程序。如果不是，则最新为5.0.0