benthos: A Go repository from hagmonk

Benthos is a high performance and resilient stream processor, able to connect various sources and sinks in a range of brokering patterns and perform hydration, enrichments, transformations and filters on payloads.

It comes with a powerful mapping language, is easy to deploy and monitor, and ready to drop into your pipeline either as a static binary, docker image, or serverless function, making it cloud native as heck.

Benthos is fully declarative, with stream pipelines defined in a single config file, allowing you to specify connectors and a list of processing stages:

input:
  gcp_pubsub:
    project: foo
    subscription: bar

pipeline:
  processors:
    - bloblang: |
        root.message = this
        root.meta.link_count = this.links.length()
        root.user.age = this.user.age.number()

output:
  redis_streams:
    url: tcp://TODO:6379
    stream: baz
    max_in_flight: 20

Delivery Guarantees

Yep, we got 'em. Benthos implements transaction based resiliency with back pressure. When connecting to at-least-once sources and sinks it guarantees at-least-once delivery without needing to persist messages during transit.

Supported Sources & Sinks

Apache Pulsar, AWS (DynamoDB, Kinesis, S3, SQS, SNS), Azure (Blob storage, Queue storage, Table storage), Cassandra, Elasticsearch, File, GCP (pub/sub), HDFS, HTTP (server and client, including websockets), Kafka, Memcached, MQTT, Nanomsg, NATS, NATS Streaming, NSQ, AMQP 0.91 (RabbitMQ), AMQP 1, Redis (streams, list, pubsub, hashes), SQL (MySQL, PostgreSQL, Clickhouse), Stdin/Stdout, TCP & UDP, sockets and ZMQ4.

Connectors are being added constantly, if something you want is missing then open an issue.

Documentation

If you want to dive fully into Benthos then don't waste your time in this dump, check out the documentation site.

For guidance on how to configure more advanced stream processing concepts such as stream joins, enrichment workflows, etc, check out the cookbooks section.

For guidance on building your own custom plugins check out this example repo.

Install

Grab a binary for your OS from here. Or use this script:

curl -Lsf https://sh.benthos.dev | bash

Or pull the docker image:

docker pull jeffail/benthos

Benthos can also be installed via Homebrew:

brew install benthos

For more information check out the getting started guide.

Run

benthos -c ./config.yaml

Or, with docker:

# Send HTTP /POST data to Kafka:
docker run --rm \
	-e "INPUT_TYPE=http_server" \
	-e "OUTPUT_TYPE=kafka" \
	-e "OUTPUT_KAFKA_ADDRESSES=kafka-server:9092" \
	-e "OUTPUT_KAFKA_TOPIC=benthos_topic" \
	-p 4195:4195 \
	jeffail/benthos

# Using your own config file:
docker run --rm -v /path/to/your/config.yaml:/benthos.yaml jeffail/benthos

Monitoring

Health Checks

Benthos serves two HTTP endpoints for health checks:

/ping can be used as a liveness probe as it always returns a 200.
/ready can be used as a readiness probe as it serves a 200 only when both the input and output are connected, otherwise a 503 is returned.

Metrics

Benthos exposes lots of metrics either to Statsd, Prometheus or for debugging purposes an HTTP endpoint that returns a JSON formatted object. The target can be specified via config.

Tracing

Benthos also emits opentracing events to a tracer of your choice (currently only Jaeger is supported) which can be used to visualise the processors within a pipeline.

Configuration

Benthos provides lots of tools for making configuration discovery, debugging and organisation easy. You can read about them here.

Environment Variables

It is possible to select fields inside a configuration file to be set via environment variables. The docker image, for example, is built with a config file where all common fields can be set this way.

Build

Build with Go (1.15 or later):

git clone git@github.com:Jeffail/benthos
cd benthos
make

Lint

Benthos uses golangci-lint for linting, which you can install with:

curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.35.2

And then run it with make lint.

Plugins

It's pretty easy to write your own custom plugins for Benthos, take a look at this repo for examples and build instructions.

Docker Builds

There's a multi-stage Dockerfile for creating a Benthos docker image which results in a minimal image from scratch. You can build it with:

make docker

Then use the image:

docker run --rm \
	-v /path/to/your/benthos.yaml:/config.yaml \
	-v /tmp/data:/data \
	-p 4195:4195 \
	benthos -c /config.yaml

There are a few examples here that show you some ways of setting up Benthos containers using docker-compose.

ZMQ4 Support

Benthos supports ZMQ4 for both data input and output. To add this you need to install libzmq4 and use the compile time flag when building Benthos:

make TAGS=ZMQ4

Or to build a docker image using CGO, which includes ZMQ:

make docker-cgo

Contributing

Contributions are welcome, please read the guidelines, come and chat (links are on the community page), and watch your back.

hagmonk/benthos