Create a Google Pub/Sub source connector to Apache Kafka®
The Google Pub/Sub source connector enables you to push from a Google Pub/Sub subscription to an Aiven for Apache Kafka® topic.
You can check the full set of available parameters and configuration options in the connector's documentation.
Prerequisites
To setup an Google Pub/Sub source connector, you need an Aiven for Apache Kafka service with Kafka Connect enabled or a dedicated Aiven for Apache Kafka Connect cluster.
Furthermore you need to collect the following information about the target Google Pub/Sub upfront:
-
GCP_PROJECT_NAME
: The GCP project name where the target Google Pub/Sub is located -
GCP_SUBSCRIPTION
: the name of the Google Pub/Sub subscription -
GCP_SERVICE_KEY
: A valid GCP service account key for theGCP_PROJECT_NAME
. To create the project key review the dedicated documentwarningThe GCP Pub/Sub source connector accepts the
GCP_SERVICE_KEY
JSON service key as a string, therefore all"
symbols within it must be escaped\"
.The
GCP_SERVICE_KEY
parameter should be in the format{\"type\": \"service_account\",\"project_id\": \"XXXXXX\", ...}
Additionally, any
\n
symbols contained in theprivate_key
field need to be escaped (by substituting with\\n
) -
KAFKA_TOPIC
: The name of the target topic in Aiven for Apache Kafka -
APACHE_KAFKA_HOST
: The hostname of the Apache Kafka service, only needed when using Avro as data format -
SCHEMA_REGISTRY_PORT
: The Apache Kafka's schema registry port, only needed when using Avro as data format -
SCHEMA_REGISTRY_USER
: The Apache Kafka's schema registry username, only needed when using Avro as data format -
SCHEMA_REGISTRY_PASSWORD
: The Apache Kafka's schema registry user password, only needed when using Avro as data format
The SCHEMA_REGISTRY
related parameters are available in the Aiven for
Apache Kafka® service page, Overview tab, and Schema Registry subtab
As of version 3.0, Aiven for Apache Kafka no longer supports Confluent Schema Registry. For more information, read the article describing the replacement, Karapace
Setup a Google Pub/Sub source connector with Aiven Console
The following example demonstrates how to setup a Google Pub/Sub source connector for Apache Kafka using the Aiven Console.
Define a Kafka Connect configuration file
Define the connector configurations in a file (we'll refer to it with
the name pubsub_source.json
) with the following content:
{
"name":"CONNECTOR_NAME",
"connector.class": "com.google.pubsub.kafka.source.CloudPubSubSourceConnector",
"kafka.topic": "KAFKA_TOPIC",
"cps.project": "GCP_PROJECT_NAME",
"cps.subscription": "GCP_SUBSCRIPTION",
"gcp.credentials.json": "GCP_SERVICE_KEY",
"key.converter": "io.confluent.connect.avro.AvroConverter",
"key.converter.schema.registry.url": "https://APACHE_KAFKA_HOST:SCHEMA_REGISTRY_PORT",
"key.converter.basic.auth.credentials.source": "USER_INFO",
"key.converter.schema.registry.basic.auth.user.info": "SCHEMA_REGISTRY_USER:SCHEMA_REGISTRY_PASSWORD",
"value.converter": "io.confluent.connect.avro.AvroConverter",
"value.converter.schema.registry.url": "https://APACHE_KAFKA_HOST:SCHEMA_REGISTRY_PORT",
"value.converter.basic.auth.credentials.source": "USER_INFO",
"value.converter.schema.registry.basic.auth.user.info": "SCHEMA_REGISTRY_USER:SCHEMA_REGISTRY_PASSWORD"
}
The configuration file contains the following entries:
-
name
: the connector name -
kafka-topic
: the target Apache Kafka topic name -
cps.project
: the GCP project name where the target Google Pub/Sub is located -
cps.subscription
: the name of the Google Pub/Sub subscription -
gcp.credentials.json
: contains the GCP service account key, correctly escaped as defined in the prerequisite phase -
key.converter
andvalue.converter
: define the message data format in the Apache Kafka topic. Theio.confluent.connect.avro.AvroConverter
converter translates messages from the Avro format. To retrieve the message schema we use Aiven's Karapace schema registry, as specified by theschema.registry.url
parameter and related credentials.noteThe
key.converter
andvalue.converter
sections are only needed when the source data is in Avro format. If omitted the messages will be read as binary format.When using Avro as source data format, you need to set following parameters
value.converter.schema.registry.url
: pointing to the Aiven for Apache Kafka schema registry URL in the form ofhttps://APACHE_KAFKA_HOST:SCHEMA_REGISTRY_PORT
with theAPACHE_KAFKA_HOST
andSCHEMA_REGISTRY_PORT
parameters retrieved in the previous step.value.converter.basic.auth.credentials.source
: to the valueUSER_INFO
, since you're going to login to the schema registry using username and password.value.converter.schema.registry.basic.auth.user.info
: passing the required schema registry credentials in the form ofSCHEMA_REGISTRY_USER:SCHEMA_REGISTRY_PASSWORD
with theSCHEMA_REGISTRY_USER
andSCHEMA_REGISTRY_PASSWORD
parameters retrieved in the previous step.
The full list of parameters is available in the dedicated GitHub page.
Create a Kafka Connect connector with the Aiven Console
To create a Kafka Connect connector, follow these steps:
-
Log in to the Aiven Console and select the Aiven for Apache Kafka® or Aiven for Apache Kafka Connect® service where the connector needs to be defined.
-
Select Connectors from the left sidebar.
-
Select Create New Connector, the button is enabled only for services with Kafka Connect enabled.
-
Select Google Pub/Sub source.
-
In the Common tab, locate the Connector configuration text box and select on Edit.
-
Paste the connector configuration (stored in the
pubsub_source.json
file) in the form. -
Select Apply.
noteThe Aiven Console parses the configuration file and fills the relevant UI fields. You can review the UI fields across the various tabs and change them if necessary. The changes will be reflected in JSON format in the Connector configuration text box.
-
After all the settings are correctly configured, select Create connector.
-
Verify the connector status under the Connectors screen.
-
Verify the presence of the data in the target Pub/Sub dataset, the table name is equal to the Apache Kafka topic name. If you need to change the target table name, you can do so using the Kafka Connect
RegexRouter
transformation.noteYou can also create connectors using the Aiven CLI command.
Example: Create a Google Pub/Sub source connector
You have a Google Pub/Sub subscription GCP_SUBSCRIPTION
that you want
to push to a Aiven for Apache Kafka topic named measurements
you can
create a source connector with the following configuration, after
replacing the placeholders for GCP_PROJECT_NAME
and GCP_SERVICE_KEY
:
{
"name":"CONNECTOR_NAME",
"connector.class": "com.google.pubsub.kafka.source.CloudPubSubSourceConnector",
"kafka.topic": "measurements",
"cps.project": "GCP_PROJECT_NAME",
"cps.subscription": "GCP_SUBSCRIPTION",
"gcp.credentials.json": "GCP_SERVICE_KEY"
}
The Apache Kafka topic format will be the default bytes by default, you
can use the AVRO schema by including the value.converter
and
key.converter
properties defined previously.