amqtt/docs/plugins/packaged_plugins.md

# Existing Plugins

With the aMQTT plugins framework, one can add additional functionality without
having to rewrite core logic in the broker or client. Plugins can be loaded and configured using
the `plugins` section of the config file (or parameter passed to the class). 


## Broker

By default, `EventLoggerPlugin`, `PacketLoggerPlugin`, `AnonymousAuthPlugin` and `BrokerSysPlugin` are activated
and configured for the broker:

```yaml
--8<-- "amqtt/scripts/default_broker.yaml"
```


??? warning "Loading plugins from EntryPoints in `pyproject.toml` has been deprecated"

    Previously, all plugins were loaded from EntryPoints:

    ```toml
    --8<-- "pyproject.toml:included"
    ```

    But the previous default config only caused 4 plugins to be active:

    ```yaml
    --8<-- "samples/legacy.yaml"
    ```

## Client

By default, the `PacketLoggerPlugin` is  activated and configured for the client:

```yaml
--8<-- "amqtt/scripts/default_client.yaml"
```

## Plugins

### Anonymous (Auth Plugin)

`amqtt.plugins.authentication.AnonymousAuthPlugin`

Authentication plugin allowing anonymous access.

::: amqtt.plugins.authentication.AnonymousAuthPlugin.Config
    options:
      heading_level: 4
      extra:
        class_style: "simple"


!!! danger
    even if `allow_anonymous` is set to `false`, the plugin will still allow access if a username is provided by the client


??? warning "EntryPoint-style configuration is deprecated"

    ```yaml
    auth:
      plugins:
        - auth_anonymous
      allow-anonymous: true # if false, providing a username will allow access
    
    ```

### Password File (Auth Plugin)

`amqtt.plugins.authentication.FileAuthPlugin`

Authentication plugin based on a file-stored user database.

::: amqtt.plugins.authentication.FileAuthPlugin.Config
    options:
      heading_level: 4
      extra:
        class_style: "simple"


??? warning "EntryPoint-style configuration is deprecated"
    ```yaml
    
    auth:
      plugins:
        - auth_file
      password-file: /path/to/password_file
    
    ```

**File Format**

The file includes `username:password` pairs, one per line.

The password should be encoded using sha-512 with `mkpasswd -m sha-512` or:

```python
import sys
from getpass import getpass
from passlib.hash import sha512_crypt

passwd = input() if not sys.stdin.isatty() else getpass()
print(sha512_crypt.hash(passwd))
```

### Taboo (Topic Plugin)

`amqtt.plugins.topic_checking.TopicTabooPlugin`

Prevents using topics named: `prohibited`, `top-secret`, and `data/classified`

**Configuration**

```yaml
plugins:
  amqtt.plugins.topic_checking.TopicTabooPlugin:
```

??? warning "EntryPoint-style configuration is deprecated"

    ```yaml
    topic-check:
      enabled: true
      plugins:
        - topic_taboo
    ```

### ACL (Topic Plugin)

`amqtt.plugins.topic_checking.TopicAccessControlListPlugin`

**Configuration**

Each acl category are a list a key-value pair, where:

> `<username>:["<topic1>", "<topic2>", ...]` *(string, list[string])*: username of the client followed by a list of allowed topics (wildcards are supported: `#`, `+`).

!!! info "`#` and `$SYS` topics"

    Per the MQTT 3.1.1 spec 4.7.2, a single `#` will not allow access to `$` broker 
    topics; need to additionally specify `$SYS/#` to allow a client full access subscribe & receive.

    Also MQTT spec prevents clients from publishing to topics starting with `$`; these will be ignored.  

If set to `None`, no restrictions are placed on client subscriptions (legacy behavior). An empty list will block clients from using any topics.

- `subscribe-acl` *(mapping)*: determines subscription access.

- `acl` *(mapping)*: Deprecated and replaced by `subscribe-acl`.

- `publish-acl` *(mapping)*: determines publish access.

- `receive-acl` *(mapping)*: determines if a message can be sent to a client.

    !!! info "Reserved usernames"

        - The username `admin` is allowed access to all topics.
        - The username `anonymous` will control allowed topics, if using the `auth_anonymous` plugin.

```yaml
plugins:
  amqtt.plugins.topic_checking.TopicAccessControlListPlugin:
    acl:
      - username: ["list", "of", "allowed", "topics", "for", "subscribing"]
      - .
    publish_acl:
      - username: ["list", "of", "allowed", "topics", "for", "publishing"]
      - .
```

??? warning "EntryPoint-style configuration is deprecated"
    ```yaml
    topic-check:
      enabled: true
      plugins:
        - topic_acl
      publish-acl:
        - username: ["list", "of", "allowed", "topics", "for", "publishing"]
        - .
      acl:
        - username: ["list", "of", "allowed", "topics", "for", "subscribing"]
        - .
    ```

### $SYS topics

`amqtt.plugins.sys.broker.BrokerSysPlugin`

Publishes, on a periodic basis, statistics about the broker

**Configuration**

- `sys_interval` - int, seconds between updates (default: 20)

```yaml
plugins:
  amqtt.plugins.sys.broker.BrokerSysPlugin:
    sys_interval: 20  # int, seconds between updates
```

**Supported Topics**

- `$SYS/broker/version` *(string)*
- `$SYS/broker/load/bytes/received` *(int)*
- `$SYS/broker/load/bytes/sent` *(int)*
- `$SYS/broker/messages/received`  *(int)*
- `$SYS/broker/messages/sent`  *(int)*
- `$SYS/broker/time`  *(int, current time in epoch seconds)*
- `$SYS/broker/uptime` *(int, seconds since broker start)*
- `$SYS/broker/uptime/formatted` *(string, start time of broker in UTC)*
- `$SYS/broker/clients/connected` *(int, number of currently connected clients)*
- `$SYS/broker/clients/disconnected` *(int, number of clients that have disconnected)*
- `$SYS/broker/clients/maximum` *(int, maximum number of clients connected)*
- `$SYS/broker/clients/total` *(int)*
- `$SYS/broker/messages/inflight` *(int)*
- `$SYS/broker/messages/inflight/in` *(int)*
- `$SYS/broker/messages/inflight/out` *(int)*
- `$SYS/broker/messages/inflight/stored` *(int)*
- `$SYS/broker/messages/publish/received` *(int)*
- `$SYS/broker/messages/publish/sent` *(int)*
- `$SYS/broker/messages/retained/count` *(int)*
- `$SYS/broker/messages/subscriptions/count` *(int)*
- `$SYS/broker/heap/size` *(float, MB)*
- `$SYS/broker/heap/maximum` *(float, MB)*
- `$SYS/broker/cpu/percent` *(float, %)*
- `$SYS/broker/cpu/maximum` *(float, %)*


### Event Logger

`amqtt.plugins.logging_amqtt.EventLoggerPlugin`

This plugin issues log messages when [broker and mqtt events](custom_plugins.md#events) are triggered:

- info level messages for `client connected` and `client disconnected`
- debug level for all others

```yaml
plugins:
  amqtt.plugins.logging_amqtt.EventLoggerPlugin:
```


### Packet Logger

`amqtt.plugins.logging_amqtt.PacketLoggerPlugin`

This plugin issues debug-level messages for [mqtt events](custom_plugins.md#events): `on_mqtt_packet_sent`
and `on_mqtt_packet_received`.

```yaml
plugins:
  amqtt.plugins.logging_amqtt.PacketLoggerPlugin:
```