nats

Type:

Available in: Cloud, Self-Managed

Subscribe to a NATS subject.

Common
Advanced

# Common config fields, showing default values
input:
  label: ""
  nats:
    urls: [] # No default (required)
    subject: foo.bar.baz # No default (required)
    queue: "" # No default (optional)
    auto_replay_nacks: true
    send_ack: true

# All config fields, showing default values
input:
  label: ""
  nats:
    urls: [] # No default (required)
    subject: foo.bar.baz # No default (required)
    queue: "" # No default (optional)
    auto_replay_nacks: true
    send_ack: true
    nak_delay: 1m # No default (optional)
    prefetch_count: 524288
    tls:
      enabled: false
      skip_cert_verify: false
      enable_renegotiation: false
      root_cas: ""
      root_cas_file: ""
      client_certs: []
    auth:
      nkey_file: ./seed.nk # No default (optional)
      nkey: "" # No default (optional)
      user_credentials_file: ./user.creds # No default (optional)
      user_jwt: "" # No default (optional)
      user_nkey_seed: "" # No default (optional)
    extract_tracing_map: root = @ # No default (optional)

Metadata

This input adds the following metadata fields to each message:

- nats_subject
- nats_reply_subject
- All message headers (when supported by the connection)

You can access these metadata fields using function interpolation.

Connection name

When monitoring and managing a production NATS system, it is often useful to know which connection a message was sent or received from. To achieve this, set the connection name option when creating a NATS connection. Redpanda Connect can then automatically set the connection name to the NATS component label, so that monitoring tools between NATS and Redpanda Connect can stay in sync.

Authentication

A number of Redpanda Connect components use NATS services. Each of these components support optional, advanced authentication parameters for NKeys and user credentials.

For an in-depth guide, see the NATS documentation.

NKeys

NATS server can use NKeys in several ways for authentication. The simplest approach is to configure the server with a list of user’s public keys. The server can then generate a challenge for each connection request from a client, and the client must respond to the challenge by signing it with its private NKey, configured in the nkey_file or nkey field.

For more details, see the NATS documentation.

User credentials

NATS server also supports decentralized authentication based on JSON Web Tokens (JWTs). When a server is configured to use this authentication scheme, clients need a user JWT and a corresponding NKey secret to connect.

You can use either of the following methods to supply the user JWT and NKey secret:

In the user_credentials_file field, enter the path to a file containing both the private key and the JWT. You can generate the file using the nsc tool.
In the user_jwt field, enter a plain text JWT, and in the user_nkey_seed field, enter the plain text NKey seed or private key.

For more details about authentication using JWTs, see the NATS documentation.

Fields

`urls`

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

Type: array

# Examples

urls:
  - nats://127.0.0.1:4222

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

`subject`

A subject to consume from. Supports wildcards for consuming multiple subjects. Either a subject or stream must be specified.

Type: string

# Examples

subject: foo.bar.baz

subject: foo.*.baz

subject: foo.bar.*

subject: foo.>

`queue`

An optional queue group to consume as.

Type: string

`auto_replay_nacks`

Whether messages that are rejected (nacked) at the output level should be automatically replayed indefinitely, eventually resulting in back pressure if the cause of the rejections is persistent. If set to false these messages will instead be deleted. Disabling auto replays can greatly improve memory efficiency of high throughput streams as the original shape of the data can be discarded immediately upon consumption and mutation.

Type: bool

Default: true

`send_ack`

Whether an automatic acknowledgment is sent as a reply to each message. When enabled, these replies are sent only when data has been delivered to all outputs.

Type: bool

Default: true

`nak_delay`

An optional delay duration on redelivering a message when negatively acknowledged.

Type: string

# Examples

nak_delay: 1m

`prefetch_count`

The maximum number of messages to pull at a time.

Type: int

Default: 524288

`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.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

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.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Type: string

Default: ""

`tls.client_certs[].cert_file`

The path of a certificate to use.

Type: string

Default: ""

`tls.client_certs[].key_file`

The path of a certificate key to use.

Type: string

Default: ""

`tls.client_certs[].password`

A plain text password for when the private key is password encrypted in PKCS#1 or PKCS#8 format. The obsolete pbeWithMD5AndDES-CBC algorithm is not supported for the PKCS#8 format.

Because the obsolete pbeWithMD5AndDES-CBC algorithm does not authenticate the ciphertext, it is vulnerable to padding oracle attacks that can let an attacker recover the plaintext.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Type: string

Default: ""

# Examples

password: foo

password: ${KEY_PASSWORD}

`auth`

Optional configuration of NATS authentication parameters.

Type: object

`auth.nkey_file`

An optional file containing a NKey seed.

Type: string

# Examples

nkey_file: ./seed.nk

`auth.nkey`

Your NKey seed or private key.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Type: string

Requires version 3.48.0 or newer

# Examples

nkey: UDXU4RCSJNZOIQHZNWXHXORDPRTGNJAHAHFRGZNEEJCPQTT2M7NLCNF4

`auth.user_credentials_file`

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

Type: string

# Examples

user_credentials_file: ./user.creds

`auth.user_jwt`

An optional plain text user JWT to use along with the corresponding user NKey seed.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Type: string

`auth.user_nkey_seed`

An optional plain text user NKey seed to use along with the corresponding user JWT.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Type: string

`extract_tracing_map`

EXPERIMENTAL: A Bloblang mapping that attempts to extract an object containing tracing propagation information, which will then be used as the root tracing span for the message. The specification of the extracted fields must match the format used by the service wide tracer.

Type: string

Requires version 4.23.0 or newer

# Examples

extract_tracing_map: root = @

extract_tracing_map: root = this.meta.span

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nats

Metadata

Connection name

Authentication

NKeys

User credentials

Fields

urls

subject

queue

auto_replay_nacks

send_ack

nak_delay

prefetch_count

tls

tls.enabled

tls.skip_cert_verify

tls.enable_renegotiation

tls.root_cas

tls.root_cas_file

tls.client_certs

tls.client_certs[].cert

tls.client_certs[].key

tls.client_certs[].cert_file

tls.client_certs[].key_file

tls.client_certs[].password

auth

auth.nkey_file

auth.nkey

auth.user_credentials_file

auth.user_jwt

auth.user_nkey_seed

extract_tracing_map

Simple online edits

Contribution guide

`urls`

`subject`

`queue`

`auto_replay_nacks`

`send_ack`

`nak_delay`

`prefetch_count`

`tls`

`tls.enabled`

`tls.skip_cert_verify`

`tls.enable_renegotiation`

`tls.root_cas`

`tls.root_cas_file`

`tls.client_certs`

`tls.client_certs[].cert`

`tls.client_certs[].key`

`tls.client_certs[].cert_file`

`tls.client_certs[].key_file`

`tls.client_certs[].password`

`auth`

`auth.nkey_file`

`auth.nkey`

`auth.user_credentials_file`

`auth.user_jwt`

`auth.user_nkey_seed`

`extract_tracing_map`