Options of the mqtt() source

The mqtt() source has the following options.

Required options: address(), fallback-topic(), and topic().

address()

Type:string
Default:tcp://localhost:1883
Required:yes

Description: Specifies the hostname or IP address, and the port number of the MQTT broker to which AxoSyslog will send the log messages.

Syntax: <protocol type>://<host>:<port>

client-id()

Type:string
Default:syslog-ng-source-{topic option}
Required:no

Description: The client-id() is used to identify the client to the MQTT server, which stores session data for each client. The session data can contains information regarding which message has been sent, received. It is not possible to set the client-id() to an empty string. To always start a new session see the cleansession() option.

cleansession()

Type:`yes
Default:no

Description: This option instruments the MQTT broker to clean the session data when connecting. The session data contains information about which message was processed.

http-proxy()

Type:URL
Default:N/A

Description: Specifies HTTP/HTTPS proxy for WebSocket connections.

keep-alive()

Type:positive integer number (in seconds)
Default:60

Description: Specifies the number of seconds that AxoSyslog keeps the connection between the broker and clients open in case there is no message traffic. When keep-alive() number of seconds pass, the connection is terminated, and you have to reconnect.

On the MQTT side, the keep alive function provides a workaround method to access connections that are still open.

password()

Type:string
Default:N/A

Description: The password used to authenticate on the MQTT broker.

persist-name()

Type:string
Default:N/A

Description: If you receive the following error message during AxoSyslog startup, set the persist-name() option of the duplicate drivers:

   Error checking the uniqueness of the persist names, please override it with persist-name option. Shutting down.

This error happens if you use identical drivers in multiple sources, for example, if you configure two file sources to read from the same file. In this case, set the persist-name() of the drivers to a custom string, for example, persist-name("example-persist-name1").

qos()

Type:number
Default:`0`

Possible values:

`0` - at most once (the fastest option)

`1` - at least once (a much slower option than `0`)

`2` - exactly once (the slowest option)

Description: The Quality of Service (QoS) level in MQTT messaging is an agreement between sender and receiver on the guarantee of delivering a message.

tls()

Type:tls options
Default:n/a

Description: This option sets various options related to TLS encryption, for example, key/certificate files and trusted CA locations. TLS can be used only with tcp-based transport protocols. For details, see TLS options.

The following options are relevant for the mqtt() tls() block: ca-dir(), ca-file(), cert-file(), cipher-suite(), key-file(), peer-verify(), ssl-version(), use-system-cert-store().

topic()

Type:string or template
Default:N/A

Description: Required option. Specifies the MQTT topic.

username()

Type:string
Default:N/A

Description: The username used to authenticate on the MQTT broker.