Publish Events to Kafka

AIStor supports publishing bucket notification events to a Kafka service endpoint.

AIStor relies on the https://github.com/Shopify/sarama project for Kafka connectivity and shares that project’s Kafka support. See the sarama Compatibility and API stability section for more details.

• Kafka minimum versions and supported versions.

  AIStor relies on the https://github.com/Shopify/sarama project for Kafka connectivity and shares that project’s Kafka support. See the sarama Compatibility and API stability section for more details.

• The AIStor mc command line tool.

  This procedure uses the mc command line tool for certain actions. See the mc Quickstart for installation instructions.

The following procedure adds a new Kafka service endpoint for supporting bucket notifications in a AIStor deployment.

1. Add the Kafka endpoint to AIStor.

   You can configure a new Kafka service endpoint using either environment variables or by setting runtime configuration settings.

   Evnironment Variables

   AIStor supports specifying the Kafka service endpoint and associated configuration settings using environment variables. The minio server process applies the specified settings on its next startup.

   The following example code sets all environment variables related to configuring a Kafka service endpoint. The minimum required variables are:

   • MINIO_NOTIFY_KAFKA_ENABLE
   • MINIO_NOTIFY_KAFKA_BROKERS

   The following lists all available variables:

   export MINIO_NOTIFY_KAFKA_ENABLE_<IDENTIFIER>="on"
   export MINIO_NOTIFY_KAFKA_BROKERS_<IDENTIFIER>="<ENDPOINT>"
   export MINIO_NOTIFY_KAFKA_TOPIC_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_KAFKA_SASL_USERNAME_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_KAFKA_SASL_PASSWORD_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_KAFKA_SASL_MECHANISM_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_KAFKA_TLS_CLIENT_AUTH_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_KAFKA_SASL_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_KAFKA_TLS_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_KAFKA_TLS_SKIP_VERIFY_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_KAFKA_CLIENT_TLS_CERT_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_KAFKA_CLIENT_TLS_KEY_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_KAFKA_QUEUE_DIR_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_KAFKA_QUEUE_LIMIT_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_KAFKA_VERSION_<IDENTIFIER>="<string>"
   export MINIO_NOTIFY_KAFKA_COMMENT_<IDENTIFIER>="<string>"
   

   • Replace <IDENTIFIER> with a unique descriptive string for the Kafka service endpoint. Use the same <IDENTIFIER> value for all environment variables related to the new target service endpoint. The examples in this procedure assume an identifier of PRIMARY.

     If the specified <IDENTIFIER> matches an existing Kafka service endpoint on the AIStor Server, the new settings override any existing settings for that endpoint. Use mc admin config get notify_kafka to review the currently configured Kafka endpoints on the AIStor Server.

   • Replace <ENDPOINT> with a comma-separated list of Kafka brokers. For example:

     "kafka1.example.com:2021,kafka2.example.com:2021"

   See Kafka Service for Bucket Notifications for complete documentation on each environment variable.

   Configuration Settings

   AIStor supports adding or updating Kafka endpoints on a running minio server process using the mc admin config set command and the notify_kafka configuration key. You must restart the minio server process to apply any new or updated configuration settings.

   The following example code sets all settings related to configuring a Kafka service endpoint. The minimum required setting is notify_kafka brokers:

   mc admin config set ALIAS/ notify_kafka:IDENTIFIER \
      brokers="<ENDPOINT>" \
      topic="<string>" \
      sasl_username="<string>" \
      sasl_password="<string>" \
      sasl_mechanism="<string>" \
      tls_client_auth="<string>" \
      tls="<string>" \
      tls_skip_verify="<string>" \
      client_tls_cert="<string>" \
      client_tls_key="<string>" \
      version="<string>" \
      queue_dir="<string>" \
      queue_limit="<string>" \
      comment="<string>"
   

   • Replace IDENTIFIER with a unique descriptive string for the Kafka service endpoint. The examples in this procedure assume an identifier of PRIMARY.

     If the specified IDENTIFIER matches an existing Kafka service endpoint on the AIStor Server, the new settings override any existing settings for that endpoint. Use mc admin config get notify_kafka to review the currently configured Kafka endpoints on the AIStor Server.

   • Replace ENDPOINT with a comma separated list of Kafka brokers. For example:

     "kafka1.example.com:2021,kafka2.example.com:2021"

   See Kafka Bucket Notification Configuration Settings for complete documentation on each setting.

   If you define both environment variables and configuration settings for the deployment, the settings defined by environment variables are used.

2. Restart the AIStor Server.

   You must restart the AIStor Server to apply the configuration changes. Use the mc admin service restart command to restart the deployment.

   mc admin service restart ALIAS
   

   Replace ALIAS with the alias of the deployment to restart.

   The minio server process prints a line on startup for each configured Kafka target similar to the following:

   SQS ARNs: arn:minio:sqs::primary:kafka
   

   You must specify the ARN resource when configuring bucket notifications with the associated Kafka deployment as a target.

3. Configure bucket notifications using the Kafka endpoint as a target.

   Use the mc event add command to add a new bucket notification event with the configured Kafka service as a target:

   mc event add ALIAS/BUCKET arn:minio:sqs::primary:kafka \
     --event EVENTS
   

   • Replace ALIAS with the alias of an AIStor Server.
   • Replace BUCKET with the name of the bucket in which to configure the event.
   • Replace EVENTS with a comma-separated list of events for which AIStor triggers notifications.

   Use mc event ls to view all configured bucket events for a given notification target:

   mc event ls ALIAS/BUCKET arn:minio:sqs::primary:kafka
   

4. Validate the configured events.

   Perform an action on the bucket for which you configured the new event and check the Kafka service for the notification data. The action required depends on which events were specified when configuring the bucket notification.

   For example, if the bucket notification configuration includes the s3:ObjectCreated:Put event, you can use the mc cp command to create a new object in the bucket and trigger a notification.

   mc cp ~/data/new-object.txt ALIAS/BUCKET
   

The following procedure updates an existing Kafka service endpoint for supporting bucket notifications in an AIStor Server.

1. List configured Kafka endpoints in the deployment.

   Use the mc admin config get command to list the currently configured Kafka service endpoints in the deployment:

   mc admin config get ALIAS/ notify_kafka
   

   Replace ALIAS with the alias of the AIStor Server.

   The command output resembles the following:

   notify_kafka:primary tls_skip_verify="off"  queue_dir="" queue_limit="0" sasl="off" sasl_password="" sasl_username="" tls_client_auth="0" tls="off" brokers="" topic="" client_tls_cert="" client_tls_key="" version=""
   notify_kafka:secondary tls_skip_verify="off"  queue_dir="" queue_limit="0" sasl="off" sasl_password="" sasl_username="" tls_client_auth="0" tls="off" brokers="" topic="" client_tls_cert="" client_tls_key="" version=""
   

   • notify_kafka is the top-level configuration key for a Kafka Notification Settings.
   • brokers specifies the Kafka service endpoint for the given notify_kafka key.
   • The suffix <IDENTIFIER> on notify_kafka describes the unique identifier for that Kafka service endpoint.

   Note the identifier for the Kafka service endpoint you want to update for the next step.

2. Update the Kafka endpoint.

   Use the mc admin config set command to set the new configuration for the Kafka service endpoint:

   mc admin config set ALIAS/ notify_kafka:<IDENTIFIER> \
      brokers="https://kafka1.example.net:9200, https://kafka2.example.net:9200" \
      topic="<string>" \
      sasl_username="<string>" \
      sasl_password="<string>" \
      sasl_mechanism="<string>" \
      tls_client_auth="<string>" \
      tls="<string>" \
      tls_skip_verify="<string>" \
      client_tls_cert="<string>" \
      client_tls_key="<string>" \
      version="<string>" \
      queue_dir="<string>" \
      queue_limit="<string>" \
      comment="<string>"
   

   The notify_kafka brokers configuration setting is the minimum required for a Kafka service endpoint. All other configuration settings are optional. See Kafka Notification Settings for a complete list of Kafka configuration settings.

3. Restart the AIStor Server.

   You must restart the AIStor Server to apply the configuration changes. Use the mc admin service restart command to restart the deployment.

   mc admin service restart ALIAS
   

   Replace ALIAS with the alias of the deployment to restart.

   The minio server process prints a line on startup for each configured Kafka target similar to the following:

   SQS ARNs: arn:minio:sqs::primary:kafka
   

4. Validate the changes.

   Perform an action on a bucket which has an event configuration using the updated Kafka service endpoint and check the Kafka service for the notification data. The action required depends on which events were specified when configuring the bucket notification.

   For example, if the bucket notification configuration includes the s3:ObjectCreated:Put event, you can use the mc cp command to create a new object in the bucket and trigger a notification.

   mc cp ~/data/new-object.txt ALIAS/BUCKET