Connecting Kafka Connect to Confluent Cloud

If you want to run a connector not yet available in Confluent Cloud, you may run it yourself in a self-managed Kafka Connect cluster. This page shows you how to configure a local Connect cluster backed by a source Apache Kafka® cluster in Confluent Cloud.

cluster into a local file.

Prerequisites

Create the Topics in Cloud Cluster

You must manually create topics for source connectors to write to.

  1. Create a page_visits topic as follows:

    ccloud kafka topic create --partitions 1 page_visits

Set up a local Connect Worker with Confluent Platform install

Download the latest ZIP or TAR distribution of Confluent Platform from https://www.confluent.io/download/. Follow the instructions based on whether you are using a Standalone Cluster or Distributed Cluster.

Replace <cloud-bootstrap-servers>, <api-key>, and <api-secret> with appropriate values from your Kafka cluster setup.

Standalone Cluster

  1. Create my-connect-standalone.properties in the config directory, whose contents look like the following (note the security configs with consumer.* and producer.* prefixes).

    cat etc/my-connect-standalone.properties
bootstrap.servers=<cloud-bootstrap-servers>

# The converters specify the format of data in Kafka and how to translate it into Connect data. Every Connect user will
# need to configure these based on the format they want their data in when loaded from or stored into Kafka
key.converter=org.apache.kafka.connect.json.JsonConverter
value.converter=org.apache.kafka.connect.json.JsonConverter
# Converter-specific settings can be passed in by prefixing the Converter's setting with the converter you want to apply
# it to
key.converter.schemas.enable=false
value.converter.schemas.enable=false

# The internal converter used for offsets and config data is configurable and must be specified, but most users will
# always want to use the built-in default. Offset and config data is never visible outside of Kafka Connect in this format.
internal.key.converter=org.apache.kafka.connect.json.JsonConverter
internal.value.converter=org.apache.kafka.connect.json.JsonConverter
internal.key.converter.schemas.enable=false
internal.value.converter.schemas.enable=false

# Store offsets on local filesystem
offset.storage.file.filename=/tmp/connect.offsets
# Flush much faster than normal, which is useful for testing/debugging
offset.flush.interval.ms=10000

ssl.endpoint.identification.algorithm=https
sasl.mechanism=PLAIN
request.timeout.ms=20000
retry.backoff.ms=500
sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required \
username="<api-key>" password="<api-secret>";
security.protocol=SASL_SSL

consumer.ssl.endpoint.identification.algorithm=https
consumer.sasl.mechanism=PLAIN
consumer.request.timeout.ms=20000
consumer.retry.backoff.ms=500
consumer.sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required \
username="<api-key>" password="<api-secret>";
consumer.security.protocol=SASL_SSL

producer.ssl.endpoint.identification.algorithm=https
producer.sasl.mechanism=PLAIN
producer.request.timeout.ms=20000
producer.retry.backoff.ms=500
producer.sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required \
username="<api-key>" password="<api-secret>";
producer.security.protocol=SASL_SSL

  2. (Optional) Add the configs to my-connect-standalone.properties to connect to Confluent Cloud Schema Registry per the example in connect-ccloud.delta on GitHub at ccloud/examples/template_delta_configs.

    # Confluent Schema Registry for Kafka Connect
value.converter=io.confluent.connect.avro.AvroConverter
value.converter.basic.auth.credentials.source=USER_INFO
value.converter.schema.registry.basic.auth.user.info=<SCHEMA_REGISTRY_API_KEY>:<SCHEMA_REGISTRY_API_SECRET>
value.converter.schema.registry.url=https://<SCHEMA_REGISTRY_ENDPOINT>

  3. Create my-file-sink.properties in the config directory, whose contents look like the following (note the security configs with consumer.* prefix):

    cat ./etc/my-file-sink.properties
name=my-file-sink
connector.class=org.apache.kafka.connect.file.FileStreamSinkConnector
tasks.max=1
topics=page_visits
file=my_file.txt

    Important

    You must include the following configuration properties if you are using a self-managed connector that requires an enterprise license.

    confluent.topic.bootstrap.servers=<cloud-bootstrap-servers>
confluent.topic.sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule \
required username="<CLUSTER_API_KEY>" password="<CLUSTER_API_SECRET>";
confluent.topic.security.protocol=SASL_SSL
confluent.topic.sasl.mechanism=PLAIN

    Important

    You must include the following configuration properties if you are using a self-managed connector that uses Reporter to write response back to Kafka (for example, the Azure Functions Sink connector or the Google Cloud Functions Sink connector) .

    reporter.admin.bootstrap.servers=<cloud-bootstrap-servers>
reporter.admin.sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule \
required username="<CLUSTER_API_KEY>" password="<CLUSTER_API_SECRET>";
reporter.admin.security.protocol=SASL_SSL
reporter.admin.sasl.mechanism=PLAIN

reporter.producer.bootstrap.servers=<cloud-bootstrap-servers>
reporter.producer.sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule \
required username="<CLUSTER_API_KEY>" password="<CLUSTER_API_SECRET>";
reporter.producer.security.protocol=SASL_SSL
reporter.producer.sasl.mechanism=PLAIN

    Important

    You must include the following configuration properties if you are using a Debezium CDC connector.

    database.history.kafka.bootstrap.servers=<cloud-bootstrap-servers>

database.history.consumer.security.protocol=SASL_SSL
database.history.consumer.ssl.endpoint.identification.algorithm=https
database.history.consumer.sasl.mechanism=PLAIN
database.history.consumer.sasl.jaas.config=
org.apache.kafka.common.security.plain.PlainLoginModule
required username="<CLUSTER_API_KEY>" password="<CLUSTER_API_SECRET>";

database.history.producer.security.protocol=SASL_SSL
database.history.producer.ssl.endpoint.identification.algorithm=https
database.history.producer.sasl.mechanism=PLAIN
database.history.producer.sasl.jaas.config=
org.apache.kafka.common.security.plain.PlainLoginModule
required username="<CLUSTER_API_KEY>" password="<CLUSTER_API_SECRET>";

  4. Run the connect-standalone script with the filenames as arguments:

    ./bin/connect-standalone  ./etc/my-connect-standalone.properties ./etc/my-file-sink.properties

    This should start a connect worker on your machine which will consume the records produced earlier using the ccloud command. If you tail the contents of my_file.txt, it should resemble the following:

    tail -f my_file.txt
{"field1": "hello", "field2": 1}
{"field1": "hello", "field2": 2}
{"field1": "hello", "field2": 3}
{"field1": "hello", "field2": 4}
{"field1": "hello", "field2": 5}
{"field1": "hello", "field2": 6}

Distributed Cluster

  1. Create connect-distributed in the config directory, whose contents look like the following (note the security configs with consumer.* and producer.* prefixes).

    bootstrap.servers=<cloud-bootstrap-servers>

group.id=connect-cluster

key.converter=org.apache.kafka.connect.json.JsonConverter
value.converter=org.apache.kafka.connect.json.JsonConverter
key.converter.schemas.enable=false
value.converter.schemas.enable=false

internal.key.converter=org.apache.kafka.connect.json.JsonConverter
internal.value.converter=org.apache.kafka.connect.json.JsonConverter
internal.key.converter.schemas.enable=false
internal.value.converter.schemas.enable=false

# Connect clusters create three topics to manage offsets, configs, and status
# information. Note that these contribute towards the total partition limit quota.
offset.storage.topic=connect-offsets
offset.storage.replication.factor=3
offset.storage.partitions=3

config.storage.topic=connect-configs
config.storage.replication.factor=3

status.storage.topic=connect-status
status.storage.replication.factor=3

offset.flush.interval.ms=10000

ssl.endpoint.identification.algorithm=https
sasl.mechanism=PLAIN
request.timeout.ms=20000
retry.backoff.ms=500
sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required \
username="<api-key>" password="<api-secret>";
security.protocol=SASL_SSL

consumer.ssl.endpoint.identification.algorithm=https
consumer.sasl.mechanism=PLAIN
consumer.request.timeout.ms=20000
consumer.retry.backoff.ms=500
consumer.sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required \
username="<api-key>" password="<api-secret>";
consumer.security.protocol=SASL_SSL

producer.ssl.endpoint.identification.algorithm=https
producer.sasl.mechanism=PLAIN
producer.request.timeout.ms=20000
producer.retry.backoff.ms=500
producer.sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required \
username="<api-key>" password="<api-secret>";
producer.security.protocol=SASL_SSL

  2. (Optional) Add the configs to connect-distributed to connect to Confluent Cloud Schema Registry per the example in connect-ccloud.delta on GitHub at ccloud/examples/template_delta_configs.

    # Confluent Schema Registry for Kafka Connect
value.converter=io.confluent.connect.avro.AvroConverter
value.converter.basic.auth.credentials.source=USER_INFO
value.converter.schema.registry.basic.auth.user.info=<SCHEMA_REGISTRY_API_KEY>:<SCHEMA_REGISTRY_API_SECRET>
value.converter.schema.registry.url=https://<SCHEMA_REGISTRY_ENDPOINT>

  3. Run Connect using the following command:

    ./bin/connect-distributed ./etc/my-connect-distributed.properties

    To test if the workers came up correctly, you can setup another file sink as follows. Create a file my-file-sink.json whose contents are as follows:

    cat my-file-sink.json
{
  "name": "my-file-sink",
  "config": {
    "connector.class": "org.apache.kafka.connect.file.FileStreamSinkConnector",
    "tasks.max": 3,
    "topics": "page_visits",
    "file": "my_file.txt"
  }
}

    Important

    You must include the following configuration properties if you are using a self-managed connector that requires an enterprise license.

    "confluent.topic.bootstrap.servers":"<cloud-bootstrap-servers>",
"confluent.topic.sasl.jaas.config":
"org.apache.kafka.common.security.plain.PlainLoginModule
required username=\"<CLUSTER_API_KEY>\" password=\"<CLUSTER_API_KEY>\";",
"confluent.topic.security.protocol":"SASL_SSL",
"confluent.topic.sasl.mechanism":"PLAIN"

    Important

    You must include the following configuration properties if you are using a self-managed connector that uses Reporter to write response back to Kafka (for example, the Azure Functions Sink connector or the Google Cloud Functions Sink connector) .

    "reporter.admin.bootstrap.servers":"<cloud-bootstrap-servers>",
"reporter.admin.sasl.jaas.config":
"org.apache.kafka.common.security.plain.PlainLoginModule
required username=\"<CLUSTER_API_KEY>\" password=\"<CLUSTER_API_KEY>\";",
"reporter.admin.security.protocol":"SASL_SSL",
"reporter.admin.sasl.mechanism":"PLAIN",

"reporter.producer.bootstrap.servers":"<cloud-bootstrap-servers>",
"reporter.producer.sasl.jaas.config":
"org.apache.kafka.common.security.plain.PlainLoginModule
required username=\"<CLUSTER_API_KEY>\" password=\"<CLUSTER_API_KEY>\";",
"reporter.producer.security.protocol":"SASL_SSL",
"reporter.producer.sasl.mechanism":"PLAIN"

    Important

    You must include the following configuration properties if you are using a Debezium CDC connector.

    "database.history.kafka.bootstrap.servers": "<cloud-bootstrap-servers>",

"database.history.consumer.security.protocol": "SASL_SSL",
"database.history.consumer.ssl.endpoint.identification.algorithm": "https",
"database.history.consumer.sasl.mechanism": "PLAIN",
"database.history.consumer.sasl.jaas.config": "org.apache.kafka.common.security.plain.PlainLoginModule
required username=\"<CLUSTER_API_KEY>\" password=\"<CLUSTER_API_KEY>\";",

"database.history.producer.security.protocol": "SASL_SSL",
"database.history.producer.ssl.endpoint.identification.algorithm": "https",
"database.history.producer.sasl.mechanism": "PLAIN",
"database.history.producer.sasl.jaas.config": "org.apache.kafka.common.security.plain.PlainLoginModule
required username=\"<CLUSTER_API_KEY>\" password=\"<CLUSTER_API_KEY>\";"

  4. Post this connector config to the worker using the curl command:

    curl -s -H "Content-Type: application/json" -X POST -d @my-file-sink.json http://localhost:8083/connectors/ | jq .

    This should give the following response:

    {
  "name": "my-file-sink",
  "config": {
    "connector.class": "org.apache.kafka.connect.file.FileStreamSinkConnector",
    "tasks.max": "1",
    "topics": "page_visits",
    "file": "my_file",
    "name": "my-file-sink"
  },
  "tasks": [],
  "type": null
}

  5. Produce some records using Confluent Cloud and tail this file to check if the connectors were successfully created.

Connect to Confluent Cloud Schema Registry

(Optional) To connect to Confluent Cloud Schema Registry, add the configs per the example in connect-ccloud.delta on GitHub at ccloud/examples/template_delta_configs.

# Confluent Schema Registry for Kafka Connect
value.converter=io.confluent.connect.avro.AvroConverter
value.converter.basic.auth.credentials.source=USER_INFO
value.converter.schema.registry.basic.auth.user.info=<SCHEMA_REGISTRY_API_KEY>:<SCHEMA_REGISTRY_API_SECRET>
value.converter.schema.registry.url=https://<SCHEMA_REGISTRY_ENDPOINT>

Set up a local Connect Worker with Docker

You can run a mix of fully-managed services in Confluent Cloud and self-managed components running in Docker. Refer to the cp-all-in-one-cloud for a Docker environment that connects any Confluent Platform component to Confluent Cloud, including Connect. To run your own connector, which is not provided in the base Docker Connect image, you will need to modify the Docker image to install the connector’s jar files from Confluent Hub, as instructed in Add Connectors or Software.

See also

For demos and testing, leverage Confluent Cloud utilities that create a full ccloud-stack and generate required configurations for Confluent Platform components to connect to your Confluent Cloud. Refer to Confluent Cloud Demos for details.

Additional Resources