Trigger

yaml

type: "io.kestra.plugin.nats.Trigger"

Consume messages periodically from a NATS subject on a JetStream-enabled NATS server and create one execution per batch.

If you would like to consume each message from a NATS subject in real-time and create one execution per message, you can use the io.kestra.plugin.nats.RealtimeTrigger instead.

Examples

Subscribe to a NATS subject, getting every message from the beginning of the subject on first trigger execution.

yaml

id: nats
namespace: company.team

tasks:
  - id: log
    type: io.kestra.plugin.core.log.Log
    message: "{{ trigger.data }}"

triggers:
  - id: watch
    type: io.kestra.plugin.nats.Trigger
    url: nats://localhost:4222
    username: nats_user
    password: nats_password
    subject: kestra.trigger
    durableId: natsTrigger
    deliverPolicy: All
    maxRecords: 1

Properties

`batchSize`

Type: integer
Dynamic: ❌
Required: ✔️
Default: 10
Minimum: >= 1

Messages are fetched by batch of given size.

`deliverPolicy`

Type: string
Dynamic: ❌
Required: ✔️
Default: All
Possible Values:
- All
- Last
- New
- ByStartSequence
- ByStartTime
- LastPerSubject

The point in the stream to receive messages from.

Possible settings are:

All: The default policy. The consumer will start receiving from the earliest available message.
Last: When first consuming messages, the consumer will start receiving messages with the last message added to the stream, or the last message in the stream that matches the consumer's filter subject if defined.
New: When first consuming messages, the consumer will only start receiving messages that were created after the consumer was created.
ByStartSequence: When first consuming messages, start at the first message having the sequence number or the next one available.
ByStartTime: When first consuming messages, start with messages on or after this time. The consumer is required to specify since which defines this start time.
LastPerSubject: When first consuming messages, start with the latest one for each filtered subject currently in the stream.

`pollDuration`

Type: string
Dynamic: ❌
Required: ✔️
Default: 2.000000000
Format: duration

Polling duration before processing message

If no messages are available, define the max duration to wait for new messages

`subject`

Type: string
Dynamic: ✔️
Required: ✔️
Min length: 1

Subject to subscribe to

`url`

Type: string
Dynamic: ✔️
Required: ✔️
Min length: 1

URL to connect to NATS server

The format is (nats://)server_url:port. You can also provide a connection token like so: nats://token@server_url:port

`conditions`

Type: array
SubType: Condition
Dynamic: ❌
Required: ❌

List of conditions in order to limit the flow trigger.

`creds`

Type: string
Dynamic: ✔️
Required: ❌

Credentials files authentification

`durableId`

Type: string
Dynamic: ✔️
Required: ❌

ID used to attach the subscription to a durable one, allowing the subscription to start back from a previous position

`interval`

Type: string
Dynamic: ❌
Required: ❌
Default: 60.000000000
Format: duration

Interval between polling.

The interval between 2 different polls of schedule, this can avoid to overload the remote system with too many calls. For most of the triggers that depend on external systems, a minimal interval must be at least PT30S. See ISO_8601 Durations for more information of available interval values.

`maxDuration`

Type: string
Dynamic: ❌
Required: ❌
Format: duration

The max duration before stopping the message polling

It's not an hard limit and is evaluated every second

`maxRecords`

Type: integer
Dynamic: ❌
Required: ❌

The max number of rows to fetch before stopping

`password`

Type: string
Dynamic: ✔️
Required: ❌

Plaintext authentication password

`since`

Type: string
Dynamic: ✔️
Required: ❌

Minimum message timestamp to start consumption from.

By default, we consume all messages from the subjects starting from beginning of logs or depending on the current durable id position. You can also provide an arbitrary start time to get all messages since this date for a new durable id. Note that if you don't provide a durable id, you will retrieve all messages starting from this date even after subsequent usage of this task.Must be a valid iso 8601 date.