Skip to main content

mqtt

Pushes messages to an MQTT broker.

# Common config fields, showing default values
output:
  label: ""
  mqtt:
    urls:
      - tcp://localhost:1883
    topic: benthos_topic
    client_id: benthos_output
    qos: 1
    connect_timeout: 30s
    write_timeout: 3s
    retained: false
    max_in_flight: 1

The topic field can be dynamically set using function interpolations described here. When sending batched messages these interpolations are performed per message part.

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: ["tcp://localhost:1883"] 

# Examples


urls:
  - tcp://localhost:1883

topic​

The topic to publish messages to.

Type: string
Default: "benthos_topic"

client_id​

An identifier for the client connection.

Type: string
Default: "benthos_output"

dynamic_client_id_suffix​

Append a dynamically generated suffix to the specified client_id on each run of the pipeline. This can be useful when clustering Benthos producers.

Type: string
Default: ""

OptionSummary
nanoidappend a nanoid of length 21 characters

qos​

The QoS value to set for each message.

Type: int
Default: 1
Options: 0, 1, 2.

connect_timeout​

The maximum amount of time to wait in order to establish a connection before the attempt is abandoned.

Type: string
Default: "30s"
Requires version 3.58.0 or newer 

# Examples


connect_timeout: 1s


connect_timeout: 500ms

write_timeout​

The maximum amount of time to wait to write data before the attempt is abandoned.

Type: string
Default: "3s"
Requires version 3.58.0 or newer 

# Examples


write_timeout: 1s


write_timeout: 500ms

retained​

Set message as retained on the topic.

Type: bool
Default: false

retained_interpolated​

Override the value of retained with an interpolable value, this allows it to be dynamically set based on message contents. The value must resolve to either true or false. This field supports interpolation functions.

Type: string
Default: ""
Requires version 3.59.0 or newer

will​

Set last will message in case of Benthos failure

Type: object

will.enabled​

Whether to enable last will messages.

Type: bool
Default: false

will.qos​

Set QoS for last will message.

Type: int
Default: 0
Options: 0, 1, 2.

will.retained​

Set retained for last will message.

Type: bool
Default: false

will.topic​

Set topic for last will message.

Type: string
Default: ""

will.payload​

Set payload for last will message.

Type: string
Default: ""

user​

A username to connect with.

Type: string
Default: ""

password​

A password to connect with.

Type: string
Default: ""

keepalive​

Max seconds of inactivity before a keepalive message is sent.

Type: int
Default: 30

tls​

Custom TLS settings can be used to override system defaults.

Type: object
Requires version 3.45.0 or newer

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: ""

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