Splunk S2S Source Connector for Confluent Platform

The Splunk S2S Source connector provides a way to integrate Splunk with Apache Kafka®. The connector receives data from Splunk universal forwarder (UF) or Splunk heavy forwarder (HF).

Important

The Splunk S2S Source connector listens on a network port. Running more than one connector task, or running in distributed mode can produce undesirable results if another task already has the port open. Confluent recommends you run the Splunk S2S Source connector in Standalone Mode.

Features

The Splunk S2S Source connector includes the following features:

• Supports one task
• Metadata support
• Data ingestion
• Multiline event parsing
• Compression support
• SSL communication support
• Dynamic Metadata Support
• HEC Record Format Support
• At Least Once Delivery

Note

• At least once delivery is supported only when acknowledgements are enabled on both the forwarder and the connector. For more details, see - At Least Once Delivery.

Supports one task

The Splunk S2S Source connector supports running only one task.

Metadata support

The Splunk S2S Source connector supports parsing metadata fields (host, source, sourcetype, and index) along with a raw event. The following is an example of a message in a Kafka topic:

{
   "event": "sample log event",
   "time": 1623175216,
   "host": "sample host",
   "source": "/opt/splunkforwarder/splunk-s2s-test.log",
   "index": "default",
   "sourcetype": "splunk-s2s-test-too_small"
}

The connector also supports parsing custom meta fields which can be configured at the forwarder’s end by using the _meta tag as shown in the following example:

[monitor://$SPLUNK_HOME/splunk-s2s-test.log]
sourcetype = test
disabled = false
_meta = testField::testValue

The following example shows a message with the previous input configuration:

{
   "event": "sample log event",
   "time": 1623175216,
   "host": "sample host",
   "source": "/opt/splunkforwarder/splunk-s2s-test.log",
   "index": "default",
   "sourcetype": "test",
   "testField": "testValue"
}

Data ingestion

The Splunk S2S Source connector supports data ingestion from the Splunk forwarder for the following input types:

• File Monitor Input
• Syslog Input
• Scripted Input
• Windows Eventlog Input

For help with configuring these input types on UFs, see Configure Inputs on Splunk Forwarder.

Multiline event parsing

The Splunk S2S Source connector also supports multiline event parsing by providing the following event break options for each sourcetype:

1. EVERY_LINE: Create new events on every new line.
2. REGEX: Create events as defined in regex.

For help with defining event break options for a sourcetype, see SourceType parsing config example.

Compression support

The Splunk S2S Source connector supports compression for communication between the connector and Splunk forwarders. To enable compression, set the following configuration property:

"splunk.s2s.compression.enable": "true"

Note

• The connector supports only native Splunk compression–that is, the compressed=true setting. It does not support the useClientSSLCompression setting provided by Splunk.
• Be sure to set compressed to true on forwarders before setting the "splunk.s2s.compression.enable": "true".

SSL communication support

The Splunk S2S Source connector supports SSL communication between the connector and Splunk forwarders. To enable SSL communication, set the following configuration properties:

"splunk.s2s.ssl.enable": "true"
"splunk.s2s.ssl.key.path":"Path to SSL Server Private Key File"
"splunk.s2s.ssl.key.password":"SSL Server Private Key Password"
"splunk.s2s.ssl.cert.chain.path":"Path to SSL Server Certificate Chain"

The Splunk S2S connector supports client authentication in SSL communication between the connector and Splunk forwarders. To enable client authentication in SSL communication, in addition to above properties, set the following configuration properties:

"splunk.s2s.ssl.client.auth.enable": "true"
"splunk.s2s.ssl.root.ca.cert.chain.path":"Path to Root CA Certificate Chain"
"splunk.s2s.ssl.cn.list":"List of authorized Common Names to validate the client certificate"

Note

• Be sure to set useSSL to true and sslRootCAPath to location of the certificate authority certificate on forwarders before setting the "splunk.s2s.ssl.enable": "true".
• Be sure to set clientCert and sslPassword on forwarders before setting the "splunk.s2s.ssl.client.auth.enable": "true".

Dynamic Metadata Support

The Splunk S2S Source Connector supports parsing dynamic metadata fields which are generated via INDEXED_EXTRACTIONS=JSON setting on Splunk HF. For more details, see Indexed field extractions.

HEC Record Format Support

The Splunk S2S Connector supports producing records in HEC compliant format where additional metadata is stored in fields key. This is compatible with Splunk HEC Sink Connector. Here is a sample record in this format -

{
   "event": "sample log event",
   "time": 1623175216,
   "host": "sample host",
   "source": "/opt/splunkforwarder/splunk-s2s-test.log",
   "index": "default",
   "sourcetype": "test",
   "fields": {
     "testField": "testValue",
     "sampleField": "sampleValue"
   }
}

To enable producing records in this format, set the following configuration -

"splunk.s2s.headers.metadata": "body",
"splunk.s2s.record.format": "hec"

For more details on this format, see Format Events for HTTP Event Collector.

At Least Once Delivery

In the event of a failure, the Splunk S2S Source connector ensures that no messages are lost, although the last few messages may be processed again. This is achieved through an acknowledgement mechanism between the connector and the forwarder. With acknowledgements, the forwarder will resend any data that the connector has not acknowledged as “received”.

To enable acknowledgement, set the following configuration -

"splunk.s2s.ack.enable": "true"

Note

• Be sure to set useACK to true on forwarders before setting the "splunk.s2s.ack.enable": "true".

For more details on at least once delivery, see Protect against loss of in-flight data.

Limitations

The Splunk S2S Source connector does not support the useClientSSLCompression setting that Splunk provides.

License

Confluent’s Splunk S2S Source connector is a Confluent Premium connector subject to the Confluent enterprise license and therefore requires an additional subscription.

You can use this connector for a 30-day trial period without a license key. After 30 days, you must purchase a connector subscription to Confluent’s Splunk S2S Source connector which includes Confluent enterprise license keys to subscribers, along with enterprise-level support for Confluent Platform and your connectors. If you are a subscriber, contact Confluent Support for more information.

For license properties, see Confluent Platform license. For information about the license topic, see License topic configuration.

Configuration properties

For a complete list of configuration properties for this connector, see Configuration Reference for Splunk S2S Source Connector for Confluent Platform.

For an example of how to get Kafka Connect connected to Confluent Cloud, see Connect Self-Managed Kafka Connect to Confluent Cloud.

Splunk Forwarder configuration

For a complete list of configuration properties for the Splunk forwarder, see Configuration Reference for Splunk Forwarder

Install the Splunk S2S Source connector

You can install this connector by using the confluent connect plugin install command, or by manually downloading the ZIP file.

Prerequisites

• You must install the connector on every machine where Connect will run.
• Kafka Broker: Confluent Platform 6.0.0 or later.
• Connect: Confluent Platform 6.0.0 or later.
• Java 1.8.
• Splunk UF version 8.x and 9.x.
• Confluent CLI (requires separate installation)
• An installation of the latest (latest) connector version.

Install the connector using Confluent Hub

To install the latest connector version, navigate to your Confluent Platform installation directory and run the following command:

confluent connect plugin install confluentinc/kafka-connect-splunk-s2s:latest

You can install a specific version by replacing latest with a version number as shown in the following example:

confluent connect plugin install confluentinc/kafka-connect-splunk-s2s:2.1.0

Install the connector manually

Download and extract the ZIP file for your connector and then follow the manual connector installation instructions.

SourceType parsing config example

The splunk.s2s.sourcetypes configuration contains a list of sourcetypes for defining regex to parse events. The following example shows how to use this configuration:

splunk.s2s.sourcetypes = typeA,typeB
splunk.s2s.sourcetype.typeA.eventbreak = EVERY_LINE
splunk.s2s.sourcetype.typeB.eventbreak = REGEX
splunk.s2s.sourcetype.typeB.regex = ([\r\n]+)(?:\d{4}-\d{2}-\d{2}\s+\d{2}:\d{2}:\d{2}\.\d{3})

Note

• By default, the event break option for each sourcetype is configured to EVERY_LINE.
• To add custom properties, such as splunk.s2s.sourcetype.typeA.eventbreak (which may not be visible initially in the user interface), click Add a property while defining the configuration.

Quick start

This Quick start uses the Splunk S2S Source connector to receive data from the Splunk UF and ingests it into Kafka.

1. Install the connector using the Confluent Hub Client.

   # run from your CP installation directory
   confluent connect plugin install confluentinc/kafka-connect-splunk-s2s:latest
   

2. Start the Confluent Platform.

   confluent local services start
   

3. Create a splunk-s2s-source.properties file with the following contents:

   name=splunk-s2s-source
   tasks.max=1
   connector.class=io.confluent.connect.splunk.s2s.SplunkS2SSourceConnector
   splunk.s2s.port=9997
   kafka.topic=splunk-s2s-events
   key.converter=org.apache.kafka.connect.storage.StringConverter
   value.converter=org.apache.kafka.connect.json.JsonConverter
   key.converter.schemas.enable=false
   value.converter.schemas.enable=false
   confluent.topic.bootstrap.servers=localhost:9092
   confluent.topic.replication.factor=1
   

4. Load the Splunk S2S Source connector.

   confluent local services connect connector load splunk-s2s-source --config splunk-s2s-source.properties
   

   Don’t use the Confluent CLI in production environments.

5. Confirm the connector is in a RUNNING state.

   confluent local services connect connector status splunk-s2s-source
   

6. Start a Splunk UF by running the Splunk UF Docker container.

   docker run -d -p 9998:9997 -e "SPLUNK_START_ARGS=--accept-license" -e "SPLUNK_PASSWORD=password" --name splunk-uf splunk/universalforwarder:9.0.0
   

7. Create a splunk-s2s-test.log file with the following sample log events:

   log event 1
   log event 2
   log event 3
   

8. Copy the splunk-s2s-test.log file to the Splunk UF Docker container using the following command:

   docker cp splunk-s2s-test.log splunk-uf:/opt/splunkforwarder/splunk-s2s-test.log
   

9. Configure the UF to monitor the splunk-s2s-test.log file:

   docker exec -it splunk-uf sudo ./bin/splunk add monitor -source /opt/splunkforwarder/splunk-s2s-test.log -auth admin:password
   

10. Configure the UF to connect to Splunk S2S Source connector:

    • For Mac/Windows systems:

      docker exec -it splunk-uf sudo ./bin/splunk add forward-server host.docker.internal:9997
      

    • For Linux systems:

      docker exec -it splunk-uf sudo ./bin/splunk add forward-server 172.17.0.1:9997
      

11. Verify the data was ingested into the Kafka topic.

    To look for events from a monitored file (splunk-s2s-test.log) in the Kafka topic, run the following command:

    kafka-console-consumer --bootstrap-server localhost:9092 --topic splunk-s2s-events --from-beginning | grep 'log event'
    

    Note

    When you use the previous command without grep, you will see many Splunk internal events get ingested in the Kafka topic as Splunk UF sends internal Splunk log events to connector by default.

12. Shut down Confluent Platform.

    confluent local destroy
    

13. Shut down the Docker container.

    docker stop splunk-uf
    docker rm splunk-uf
    

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