= nats :type: input :status: stable :categories: ["Services"] //// THIS FILE IS AUTOGENERATED! To make changes, edit the corresponding source file under: https://github.com/redpanda-data/connect/tree/main/internal/impl/. And: https://github.com/redpanda-data/connect/tree/main/cmd/tools/docs_gen/templates/plugin.adoc.tmpl //// // © 2024 Redpanda Data Inc. component_type_dropdown::[] Subscribe to a NATS subject. [tabs] ====== Common:: + -- ```yml # 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 ``` -- Advanced:: + -- ```yml # 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: '!!!SECRET_SCRUBBED!!!' # 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: ```text - nats_subject - nats_reply_subject - All message headers (when supported by the connection) ``` You can access these metadata fields using xref:configuration:interpolation.adoc#bloblang-queries[function interpolation]. == Connection name When monitoring and managing a production NATS system, it is often useful to know which connection a message was send/received from. This can be achieved by setting the connection name option when creating a NATS connection. Benthos will automatically set the connection name based off the label of the given NATS component, so that monitoring tools between NATS and Benthos can stay in sync. == Authentication There are several components within Benthos which uses NATS services. You will find that each of these components support optional advanced authentication parameters for https://docs.nats.io/nats-server/configuration/securing_nats/auth_intro/nkey_auth[NKeys^] and https://docs.nats.io/using-nats/developer/connecting/creds[User Credentials^]. See an https://docs.nats.io/running-a-nats-service/nats_admin/security/jwt[in-depth tutorial^]. === 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` or `nkey` field. https://docs.nats.io/running-a-nats-service/configuration/securing_nats/auth_intro/nkey_auth[More details^]. === User credentials NATS server supports decentralized authentication based on JSON Web Tokens (JWT). Clients need an https://docs.nats.io/nats-server/configuration/securing_nats/jwt#json-web-tokens[user JWT^] and a corresponding https://docs.nats.io/running-a-nats-service/configuration/securing_nats/auth_intro/nkey_auth[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 https://docs.nats.io/nats-tools/nsc[nsc tool^]. Alternatively, the `user_jwt` field can contain a plain text JWT and the `user_nkey_seed`can contain the plain text NKey Seed. https://docs.nats.io/using-nats/developer/connecting/creds[More details^]. == 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` ```yml # 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` ```yml # 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` Control whether ACKS are sent as a reply to each message. When enabled, these replies are sent only once the 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` ```yml # 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. [CAUTION] ==== This field contains sensitive information that usually shouldn't be added to a config directly, read our xref:configuration:secrets.adoc[secrets page for more info]. ==== *Type*: `string` *Default*: `""` ```yml # 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*: `""` ```yml # 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*: `[]` ```yml # 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. [CAUTION] ==== This field contains sensitive information that usually shouldn't be added to a config directly, read our xref:configuration:secrets.adoc[secrets page for more info]. ==== *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. [CAUTION] ==== This field contains sensitive information that usually shouldn't be added to a config directly, read our xref:configuration:secrets.adoc[secrets page for more info]. ==== *Type*: `string` *Default*: `""` ```yml # 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` ```yml # Examples nkey_file: ./seed.nk ``` === `auth.nkey` The NKey seed. [CAUTION] ==== This field contains sensitive information that usually shouldn't be added to a config directly, read our xref:configuration:secrets.adoc[secrets page for more info]. ==== *Type*: `string` Requires version 4.38.0 or newer ```yml # Examples nkey: UDXU4RCSJNZOIQHZNWXHXORDPRTGNJAHAHFRGZNEEJCPQTT2M7NLCNF4 ``` === `auth.user_credentials_file` An optional file containing user credentials which consist of an user JWT and corresponding NKey seed. *Type*: `string` ```yml # Examples user_credentials_file: ./user.creds ``` === `auth.user_jwt` An optional plain text user JWT (given along with the corresponding user NKey Seed). [CAUTION] ==== This field contains sensitive information that usually shouldn't be added to a config directly, read our xref:configuration:secrets.adoc[secrets page for more info]. ==== *Type*: `string` === `auth.user_nkey_seed` An optional plain text user NKey Seed (given along with the corresponding user JWT). [CAUTION] ==== This field contains sensitive information that usually shouldn't be added to a config directly, read our xref:configuration:secrets.adoc[secrets page for more info]. ==== *Type*: `string` === `extract_tracing_map` EXPERIMENTAL: A xref:guides:bloblang/about.adoc[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 ```yml # Examples extract_tracing_map: root = @ extract_tracing_map: root = this.meta.span ```