Prometheus-kafka-adapter is a service which receives Prometheus metrics through remote_write, marshal into JSON and sends them into Kafka.

We use prometheus-kafka-adapter internally at Telefonica for dumping Prometheus metrics into an object storage in diferent clouds, through Kafka and Kafka-Connect.

It is able to write JSON or Avro-JSON messages in a kafka topic, depending on the SERIALIZATION_FORMAT configuration variable.

{
  "timestamp": "1970-01-01T00:00:00Z",
  "value": "9876543210",
  "name": "up",

  "labels": {
    "__name__": "up",
    "label1": "value1",
    "label2": "value2"
  }
}

timestamp and value are reserved values, and can't be used as label names. __name__ is a special label that defines the name of the metric and is copied as name to the top level for convenience.

The Avro-JSON serialization is the same. See the Avro schema.

There is a docker image telefonica/prometheus-kafka-adapter:1.3.0 available on Docker Hub.

Prometheus-kafka-adapter listens for metrics coming from Prometheus and sends them to Kafka. This behaviour can be configured with the following environment variables:

• KAFKA_BROKER_LIST: defines kafka endpoint and port, defaults to kafka:9092.
• KAFKA_TOPIC: defines kafka topic to be used, defaults to metrics.
• KAFKA_COMPRESSION: defines the compression type to be used, defaults to none.
• KAFKA_BATCH_NUM_MESSAGES: defines the number of messages to batch write, defaults to 10000.
• SERIALIZATION_FORMAT: defines the serialization format, can be json, avro-json, defaults to json.
• PORT: defines http port to listen, defaults to 8080, used directly by gin.
• BASIC_AUTH_USERNAME: basic auth username to be used for receive endpoint, defaults is no basic auth.
• BASIC_AUTH_PASSWORD: basic auth password to be used for receive endpoint, defaults is no basic auth.
• LOG_LEVEL: defines log level for logrus, can be debug, info, warn, error, fatal or panic, defaults to info.
• GIN_MODE: manage gin debug logging, can be debug or release.

Prometheus needs to have a remote_write url configured, pointing to the '/receive' endpoint of the host and port where the prometheus-kafka-adapter service is running. For example:

remote_write:
  - url: "http://prometheus-kafka-adapter:8080/receive"

go test
go build

With issues:

• Use the search tool before opening a new issue.
• Please provide source code and commit sha if you found a bug.
• Review existing issues and provide feedback or react to them.

With pull requests:

• Open your pull request against master
• It should pass all tests in the continuous integrations system (TravisCI).
• You should add/modify tests to cover your proposed code changes.
• If your pull request contains a new feature, please document it on the README.

Copyright 2018 Telefónica

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.