nats_kv

Perform operations on a NATS key-value bucket.

Introduced in version 4.12.0.

  • Common

  • Advanced

# Common configuration fields, showing default values
label: ""
nats_kv:
  urls: [] # No default (required)
  bucket: my_kv_bucket # No default (required)
  operation: "" # No default (required)
  key: foo # No default (required)
# All configuration fields, showing default values
label: ""
nats_kv:
  urls: [] # No default (required)
  bucket: my_kv_bucket # No default (required)
  operation: "" # No default (required)
  key: foo # No default (required)
  revision: "42" # No default (optional)
  timeout: 5s
  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)

KV operations

The NATS KV processor supports many KV operations using the operation field. Along with get, put, and delete, this processor supports atomic operations like update and create, as well as utility operations like purge, history, and keys.

Metadata

This processor adds the following metadata fields to each message, depending on the chosen operation:

get, get_revision

- nats_kv_key
- nats_kv_bucket
- nats_kv_revision
- nats_kv_delta
- nats_kv_operation
- nats_kv_created

create, update, delete, purge

- nats_kv_key
- nats_kv_bucket
- nats_kv_revision
- nats_kv_operation

keys

- nats_kv_bucket

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

bucket

The name of the KV bucket.

Type: string

# Examples

bucket: my_kv_bucket

operation

The operation to perform on the KV bucket.

Type: string

Option Summary

create

Adds the key/value pair if it does not exist. Returns an error if it already exists.

delete

Deletes the key/value pair, but keeps historical values.

get

Returns the latest value for key.

get_revision

Returns the value of key for the specified revision.

history

Returns historical values of key as an array of objects containing the following fields: key, value, bucket, revision, delta, operation, created.

keys

Returns the keys in the bucket which match the keys_filter as an array of strings.

purge

Deletes the key/value pair and all historical values.

put

Places a new value for the key into the store.

update

Updates the value for key only if the revision matches the latest revision.

key

The key for each message. Supports wildcards for the history and keys operations. This field supports interpolation functions.

Type: string

# Examples

key: foo

key: foo.bar.baz

key: foo.*

key: foo.>

key: foo.${! json("meta.type") }

revision

The revision of the key to operate on. Used for get_revision and update operations. This field supports interpolation functions.

Type: string

# Examples

revision: "42"

revision: ${! @nats_kv_revision }

timeout

The maximum period to wait on an operation before aborting and returning an error.

Type: string

Default: "5s"

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