nats_stream.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 input

import (
	"github.com/Jeffail/benthos/lib/input/reader"
	"github.com/Jeffail/benthos/lib/log"
	"github.com/Jeffail/benthos/lib/metrics"
	"github.com/Jeffail/benthos/lib/types"
)

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

func init() {
	Constructors[TypeNATSStream] = TypeSpec{
		constructor: NewNATSStream,
		description: `
Subscribe to a NATS Stream subject, which is at-least-once. Joining a queue is
optional and allows multiple clients of a subject to consume using queue
semantics.

Tracking and persisting offsets through a durable name is also optional and
works with or without a queue. If a durable name is not provided then subjects
are consumed from the most recently published message.

### Metadata

This input adds the following metadata fields to each message:

` + "```" + `
- nats_stream_subject
` + "```" + `

You can access these metadata fields using
[function interpolation](../config_interpolation.md#metadata).`,
	}
}

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

// NewNATSStream creates a new NATSStream input type.
func NewNATSStream(conf Config, mgr types.Manager, log log.Modular, stats metrics.Type) (Type, error) {
	n, err := reader.NewNATSStream(conf.NATSStream, log, stats)
	if err != nil {
		return nil, err
	}
	return NewReader("nats_stream", n, log, stats)
}

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