mosquitto/plugins

Plugins

This directory contains plugins for use with Mosquitto.

Dynamic security

This is a fully functioning plugin that implements authentication and access control, with configuration via a $CONTROL topic. See the readme in dynamic-security for more information.

Examples / Add properties

This is an example plugin that demonstrates adding MQTT v5 properties to messages, and how to get client information.

Examples / Authenticate by IP address

This is an example plugin that demonstrates a basic authentication callback that allows clients based on their IP address. Password based authentication is preferred over this very simple type of access control.

Examples / Client lifetime stats

This is an example plugin that collects counts of how long client sessions last, in different time buckets of 0, 1, 2, 5, 10, 20, 50, 100, 200, 500, 1k, 2k, 5k, 10k, 20k, 50k, 100k, 200k, 500k, 1M, 2M, 5M, 10M, 20M, 50M, 100M, 200M, 500M seconds. It periodically publishes the counts at $SYS/broker/client/lifetimes/<bucket>.

Examples / Client properties

This is an example plugin that demonstrates some of the functions for retrieving client information such as client id and username.

Examples / Connection state

This is an example plugin to demonstrate the use of the connect and disconnect events. It publishes messages to $SYS/broker/connection/client//state for every client that connects to the broker, to indicate the connection state of that client.

Examples / Deferred authentication

This is an example plugin to demonstrate how a plugin can carry out delayed basic authentication. This method should be used where the plugin sends an authentication request to an external server so that if there is a delay in getting a response it does not block the broker. The plugin may spawn extra threads to handle the authentication requests, but the call to mosquitto_complete_basic_auth() must happen in the main Mosquitto thread.

Examples / Message timestamp

This is an example plugin to demonstrate how it is possible to attach MQTT v5 properties to messages after they have been received, and before they are sent on to subscribers.

This plugin attaches a user-property property to each message which contains the ISO-8601 timestamp of the time the message was received by the broker. This means it is possible for MQTT v5 clients to see how old a retained message is, for example.

Examples / Payload modification

This is an example plugin to demonstrate how it is possible to modify the payload of messages after they have been received, and before they are sent on to subscribers.

If you are considering using this feature, you should be very certain you have verified the payload is the correct format before modifying it.

This plugin adds the text string "hello " to the beginning of each payload, so with anything other than simple plain text messages it will corrupt the payload contents.

Examples / Payload size stats

This is an example plugin that collects counts of payload message sizes, in time buckets of 0, 1, 2, 5, 10, 20, 50, 100, 200, 500, 1k, 2k, 5k, 10k, 20k, 50k, 100k, 200k, 500k, 1M, 2M, 5M, 10M, 20M, 50M, 100M, 200M, 500M bytes. It periodically publishes the counts at $SYS/broker/publish/sizes/<bucket>.

Examples / Print IP on publish

This is an example plugin that prints out client ID and IP address of any client that publishes on a particular topic.

Examples / Topic modification

This is an example plugin to demonstrate how it is possible to modify the topic of messages after they have been received, and before they are sent on to subscribers.

This plugin removes the /uplink end part of topics that match the pattern device/+/data/uplink, so devices publishing to device/0001/data/uplink will effectively be publishing to device/0001/data.

Examples / Wildcard temp

This is an example plugin that denies access to the # subscription topic only. This prevents clients from discovering which topics are active and reduces outgoing bandwidth. If clients connect with username wildcard and subscribes to # they will be allowed 20 seconds of access, after which the subscription will be silently removed.