A go-cloud pubsub plugin for nats io jetstream.

Package jetstreampubsub provides a pubsub implementation for NATS.io Jetstream. Use OpenTopic to construct a *pubsub.Topic, and/or OpenSubscription to construct a *pubsub.Subscription. This package uses gob to encode and decode driver.Message to []byte.

For pubsub.OpenTopic and pubsub.OpenSubscription, natspubsub registers for the scheme "nats". The default URL opener will connect to a default server based on the environment variable "NATS_SERVER_URL".

For servers that support it (NATS Server 2.2.0 or later), messages can be encoded using native NATS message headers, and native message content. This provides full support for non-Go clients. Versions prior to 2.2.0 uses gob.Encoder to encode the message headers and content, which limits the subscribers only to Go clients. To use this feature, set the query parameter "natsv2" in the URL. If no value is provided, it assumes the value is true. Otherwise, the value needs to be parsable as a boolean. For example:

• nats://mysubject?natsv2
• nats://mysubject?natsv2=true

This feature can also be enabled by setting the UseV2 field in the URLOpener. If the server does not support this feature, any attempt to use it will result in an error. Using native NATS message headers and content is more efficient than using gob.Encoder, and allows non-Go clients to subscribe to the topic and receive messages. It is recommended to use this feature if the server supports it.

To customize the URL opener, or for more details on the URL format, see URLOpener. See https://gocloud.dev/concepts/urls/ for background information.

NATS supports at-most-semantics; applications need not call Message.Ack, and must not call Message.Nack. See https://godoc.org/gocloud.dev/pubsub#hdr-At_most_once_and_At_least_once_Delivery for more background.