Skip to main content

nats_stream

Publish to a NATS Stream subject.

# Common config fields, showing default values
output:
label: ""
nats_stream:
urls:
- nats://127.0.0.1:4222
cluster_id: test-cluster
subject: benthos_messages
client_id: benthos_client
max_in_flight: 1

Authentication

There are several components within Benthos which utilise NATS services. You will find that each of these components support optional advanced authentication parameters for NKeys and User Credentials.

An in depth tutorial can be found here.

NKey file

The NATS server can use these NKeys in several ways for authentication. The simplest is for the server to be configured with a list of known public keys and for the clients to respond to the challenge by signing it with its private NKey configured in the nkey_file field.

More details here.

User Credentials file

NATS server supports decentralized authentication based on JSON Web Tokens (JWT). Clients need an user JWT and a corresponding NKey secret when connecting to a server which is configured to use this authentication scheme.

The user_credentials_file field should point to a file containing both the private key and the JWT and can be generated with the nsc tool.

More details here.

Performance

This output benefits from sending multiple messages in flight in parallel for improved performance. You can tune the max number of in flight messages with the field max_in_flight.

Fields

urls

A list of URLs to connect to. If an item of the list contains commas it will be expanded into multiple URLs.

Type: array
Default: ["nats://127.0.0.1:4222"]

# Examples
urls:
- nats://127.0.0.1:4222
urls:
- nats://username:password@127.0.0.1:4222

cluster_id

The cluster ID to publish to.

Type: string
Default: "test-cluster"

subject

The subject to publish to.

Type: string
Default: "benthos_messages"

client_id

The client ID to connect with.

Type: string
Default: "benthos_client"

max_in_flight

The maximum number of messages to have in flight at a given time. Increase this to improve throughput.

Type: int
Default: 1

tls

Custom TLS settings can be used to override system defaults.

Type: object

tls.enabled

Whether custom TLS settings are enabled.

Type: bool
Default: false

tls.skip_cert_verify

Whether to skip server side certificate verification.

Type: bool
Default: false

tls.enable_renegotiation

Whether to allow the remote server to repeatedly request renegotiation. Enable this option if you're seeing the error message local error: tls: no renegotiation.

Type: bool
Default: false
Requires version 3.45.0 or newer

tls.root_cas

An optional root certificate authority to use. This is a string, representing a certificate chain from the parent trusted root certificate, to possible intermediate signing certificates, to the host certificate.

Type: string
Default: ""

# Examples
root_cas: |-
-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----

tls.root_cas_file

An optional path of a root certificate authority file to use. This is a file, often with a .pem extension, containing a certificate chain from the parent trusted root certificate, to possible intermediate signing certificates, to the host certificate.

Type: string
Default: ""

# Examples
root_cas_file: ./root_cas.pem

tls.client_certs

A list of client certificates to use. For each certificate either the fields cert and key, or cert_file and key_file should be specified, but not both.

Type: array
Default: []

# Examples
client_certs:
- cert: foo
key: bar
client_certs:
- cert_file: ./example.pem
key_file: ./example.key

tls.client_certs[].cert

A plain text certificate to use.

Type: string
Default: ""

tls.client_certs[].key

A plain text certificate key to use.

Type: string
Default: ""

tls.client_certs[].cert_file

The path to a certificate to use.

Type: string
Default: ""

tls.client_certs[].key_file

The path of a certificate key to use.

Type: string
Default: ""

auth

Optional configuration of NATS authentication parameters.

Type: object

auth.nkey_file

An optional file containing a NKey seed.

Type: string
Default: ""

# Examples
nkey_file: ./seed.nk

auth.user_credentials_file

An optional file containing user credentials which consist of an user JWT and corresponding NKey seed.

Type: string
Default: ""

# Examples
user_credentials_file: ./user.creds