kafka.go

// Copyright (c) 2014 Ashley Jeffs
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package output

import (
	"github.com/Jeffail/benthos/lib/output/writer"
	"github.com/Jeffail/benthos/lib/types"
	"github.com/Jeffail/benthos/lib/util/service/log"
	"github.com/Jeffail/benthos/lib/util/service/metrics"
)

//------------------------------------------------------------------------------

func init() {
	Constructors["kafka"] = TypeSpec{
		constructor: NewKafka,
		description: `
The kafka output type writes messages to a kafka broker, these messages are
acknowledged, which is propagated back to the input. The config field
'ack_replicas' determines whether we wait for acknowledgement from all replicas
or just a single broker.

It is possible to specify a compression codec to use out of the following
options: none, snappy, lz4 and gzip.

If the field 'key' is not empty then each message will be given its contents as
a key. This field can be dynamically set using function interpolations described
[here](../config_interpolation.md#functions).

By default the paritioner will select partitions based on a hash of the key
value. If the key is empty then a partition is chosen at random. You can
alternatively force the partitioner to round-robin partitions with the field
'round_robin_partitions'.

The target version by default will be the oldest supported, as it is expected
that the server will be backwards compatible. In order to support newer client
features you should increase this version up to the known version of the target
server.`,
	}
}

//------------------------------------------------------------------------------

// NewKafka creates a new Kafka output type.
func NewKafka(conf Config, mgr types.Manager, log log.Modular, stats metrics.Type) (Type, error) {
	k, err := writer.NewKafka(conf.Kafka, log, stats)
	if err != nil {
		return nil, err
	}
	return NewWriter(
		"kafka", k, log, stats,
	)
}

//------------------------------------------------------------------------------