nats_jetstream

Reads messages from NATS JetStream subjects.

Introduced in version 3.46.0.

  • Common

  • Advanced

# Common config fields, showing default values
input:
  label: ""
  nats_jetstream:
    urls: [] # No default (required)
    queue: "" # No default (optional)
    subject: foo.bar.baz # No default (optional)
    durable: "" # No default (optional)
    stream: "" # No default (optional)
    bind: false # No default (optional)
    deliver: all
# All config fields, showing default values
input:
  label: ""
  nats_jetstream:
    urls: [] # No default (required)
    queue: "" # No default (optional)
    subject: foo.bar.baz # No default (optional)
    durable: "" # No default (optional)
    stream: "" # No default (optional)
    bind: false # No default (optional)
    deliver: all
    ack_wait: 30s
    max_ack_pending: 1024
    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)

Consume mirrored streams

When a stream being consumed is mirrored in a different JetStream domain, the stream cannot be resolved from the subject name alone. You must specify the stream name as well as the subject (if applicable).

Metadata

This input adds the following metadata fields to each message:

- nats_subject
- nats_sequence_stream
- nats_sequence_consumer
- nats_num_delivered
- nats_num_pending
- nats_domain
- nats_timestamp_unix_nano

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

queue

An optional queue group to consume as.

Type: string

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.>

durable

Preserve the state of your consumer under a durable name.

Type: string

stream

A stream to consume from. Either a subject or stream must be specified.

Type: string

bind

Indicates that the subscription should use an existing consumer.

Type: bool

deliver

Determines which messages to deliver when consuming without a durable subscriber.

Type: string

Default: "all"

Option Summary

all

Deliver all available messages.

last

Deliver starting with the last published messages.

last_per_subject

Deliver starting with the last published message per subject.

new

Deliver starting from now, not taking into account any previous messages.

ack_wait

The maximum amount of time NATS server should wait for an ack from consumer.

Type: string

Default: "30s"

# Examples

ack_wait: 100ms

ack_wait: 5m

max_ack_pending

The maximum number of outstanding acks to be allowed before consuming is halted.

Type: int

Default: 1024

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 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