matrix-docker-ansible-deploy/docs/configuring-playbook-bot-draupnir.md

Setting up Draupnir (optional)

The playbook can install and configure the Draupnir moderation bot for you.

See the project's documentation to learn what it does and why it might be useful to you.

This documentation page is about installing Draupnir in bot mode. As an alternative, you can run a multi-instance Draupnir deployment by installing Draupnir in appservice mode (called Draupnir-for-all) instead.

If your migrating from Mjolnir skip to this section.

Prerequisites

Register the bot account

The playbook does not automatically create users for you. You need to register the bot user manually before setting up the bot.

Choose a strong password for the bot. You can generate a good password with a command like this: pwgen -s 64 1.

You can use the playbook to register a new user:

ansible-playbook -i inventory/hosts setup.yml --extra-vars='username=bot.draupnir password=PASSWORD_FOR_THE_BOT admin=no' --tags=register-user

If you would like Draupnir to be able to deactivate users, move aliases, shutdown rooms, show abuse reports (see below), etc then it must be a server admin so you need to change admin=no to admin=yes in the command above.

Get an access token

The bot requires an access token to be able to connect to your homeserver. Refer to the documentation on how to obtain an access token.

Make sure the account is free from rate limiting

If your homeserver's implementation is Synapse, you will need to prevent it from rate limiting the bot's account. This is a required step. If you do not configure it, Draupnir will crash.

This can be done using Synapse's Admin APIs. They can be accessed both externally and internally.

To expose the APIs publicly, add the following configuration to your inventory/host_vars/matrix.example.com/vars.yml file.

matrix_synapse_container_labels_public_client_synapse_admin_api_enabled: true

The APIs can also be accessed via Synapse Admin, a web UI tool you can use to administrate users, rooms, media, etc. on your Matrix server. The playbook can install and configure Synapse Admin for you. For details about it, see this page.

Note: access to the APIs is restricted with a valid access token, so exposing them publicly should not be a real security concern. Still, doing so is not recommended for additional security. See official Synapse reverse-proxying recommendations.

To discharge rate limiting, run the following command on systems that ship curl (note that it does not work on outdated Windows 10). Even if the APIs are not exposed to the internet, you should still be able to run the command on the homeserver locally. Before running it, make sure to replace @bot.draupnir:example.com with the MXID of your Draupnir:

curl --header "Authorization: Bearer <access_token>" -X POST https://matrix.example.com/_synapse/admin/v1/users/@bot.draupnir:example.com/override_ratelimit

You can obtain an access token for a homeserver admin account in the same way as you can do so for Draupnir itself. If you have made Draupnir an admin, you can just use the Draupnir token.

Create a management room

Using your own account, create a new invite only room that you will use to manage the bot. This is the room where you will see the status of the bot and where you will send commands to the bot, such as the command to ban a user from another room. Anyone in this room can control the bot so it is important that you only invite trusted users to this room.

If you make the management room encrypted (E2EE), then you MUST enable and use Pantalaimon (see below).

Once you have created the room you need to copy the room ID so you can tell the bot to use that room. In Element Web you can do this by going to the room's settings, clicking Advanced, and then copying the internal room ID. The room ID will look something like !qporfwt:example.com.

Finally invite the @bot.draupnir:example.com account you created earlier into the room.

Adjusting the playbook configuration

Add the following configuration to your inventory/host_vars/matrix.example.com/vars.yml file. Make sure to replace MANAGEMENT_ROOM_ID_HERE.

# Enable Draupnir
matrix_bot_draupnir_enabled: true

matrix_bot_draupnir_management_room: "MANAGEMENT_ROOM_ID_HERE"

End-to-End Encryption support

Decide whether you want Draupnir to be capable of operating in end-to-end encrypted (E2EE) rooms. This includes the management room and the moderated rooms.

To support E2EE, Draupnir needs to use Pantalaimon.

Configuration with E2EE support

When using Pantalaimon, Draupnir will log in to its bot account itself through Pantalaimon, so configure its username and password.

Add the following configuration to your inventory/host_vars/matrix.example.com/vars.yml file (adapt to your needs):

# Enable Pantalaimon. See docs/configuring-playbook-pantalaimon.md
matrix_pantalaimon_enabled: true

# Tell Draupnir to use Pantalaimon
matrix_bot_draupnir_pantalaimon_use: true

# User name and password for the bot you have created above. Required when using Pantalaimon.
matrix_bot_draupnir_pantalaimon_username: "bot.draupnir"
matrix_bot_draupnir_pantalaimon_password: "PASSWORD_FOR_THE_BOT"

The playbook's group_vars will configure other required settings. If using this role separately without the playbook, you also need to configure the two URLs that Draupnir uses to reach the homeserver, one through Pantalaimon and one "raw". This example is taken from the playbook's group_vars:

# Endpoint URL that Draupnir uses to interact with the Matrix homeserver (client-server API).
# Set this to the pantalaimon URL if you're using that.
matrix_bot_draupnir_homeserver_url: "{{ 'http://matrix-pantalaimon:8009' if matrix_bot_draupnir_pantalaimon_use else matrix_addons_homeserver_client_api_url }}"

# Endpoint URL that Draupnir could use to fetch events related to reports (client-server API and /_synapse/),
# only set this to the public-internet homeserver client API URL, do NOT set this to the pantalaimon URL.
matrix_bot_draupnir_raw_homeserver_url: "{{ matrix_addons_homeserver_client_api_url }}"

Configuration without E2EE support

When NOT using Pantalaimon, Draupnir does not log in by itself and you must give it an access token for its bot account.

Add the following configuration to your inventory/host_vars/matrix.example.com/vars.yml file. Make sure to replace ACCESS_TOKEN_HERE with the one created above.

matrix_bot_draupnir_access_token: "ACCESS_TOKEN_HERE"

Abuse Reports

Draupnir supports two methods to receive reports in the management room.

The first method intercepts the report API endpoint of the client-server API, which requires integration with the reverse proxy in front of the homeserver. If you are using traefik, this playbook can set this up for you:

matrix_bot_draupnir_abuse_reporting_enabled: true

The other method polls an Synapse Admin API endpoint, hence it is available only if using Synapse and if the Draupnir user is an admin (see above). To enable it, set pollReports: true on vars.yml file as below.

Extending the configuration

You can configure additional options by adding the matrix_bot_draupnir_configuration_extension_yaml variable.

For example, to change Draupnir's pollReports option to true, add the following configuration to your inventory/host_vars/matrix.example.com/vars.yml file:

matrix_bot_draupnir_configuration_extension_yaml: |
  # Your custom YAML configuration goes here.
  # This configuration extends the default starting configuration (`matrix_bot_draupnir_configuration_yaml`).
  #
  # You can override individual variables from the default configuration, or introduce new ones.
  #
  # If you need something more special, you can take full control by
  # completely redefining `matrix_bot_draupnir_configuration_yaml`.
  pollReports: true  

Migrating from Mjolnir (Only required if migrating)

Replace your matrix_bot_mjolnir config with matrix_bot_draupnir config. Also disable Mjolnir if you're doing migration.

That is all you need to do due to that Draupnir can complete migration on its own.

Installing

After configuring the playbook, run it with playbook tags as below:

ansible-playbook -i inventory/hosts setup.yml --tags=setup-all,ensure-matrix-users-created,start

Notes:

• The ensure-matrix-users-created playbook tag makes the playbook automatically create the bot's user account.

• The shortcut commands with the just program are also available: just install-all or just setup-all

  just install-all is useful for maintaining your setup quickly (2x-5x faster than just setup-all) when its components remain unchanged. If you adjust your vars.yml to remove other components, you'd need to run just setup-all, or these components will still remain installed.

• If you change the Pantalaimon's password (matrix_bot_draupnir_pantalaimon_password in your vars.yml file) subsequently, its credentials on the homeserver won't be updated automatically. If you'd like to change the password, use a tool like synapse-admin to change it, and then update matrix_bot_draupnir_pantalaimon_password to let Pantalaimon know its new password.

Usage

You can refer to the upstream documentation for additional ways to use and configure Draupnir and for a more detailed usage guide.

Below is a non-exhaustive quick-start guide for the impatient.

Making Draupnir join and protect a room

Draupnir can be told to self-join public rooms, but it's better to follow this flow which works well for all kinds of rooms:

1. Invite the bot to the room manually (inviting Draupnir to rooms). Before joining, the bot may ask for confirmation in the Management Room

2. Give the bot permissions to do its job

3. Tell it to protect the room (using the rooms command) by sending the following command to the Management Room: !draupnir rooms add !qporfwt:example.com

To have Draupnir provide useful room protection, you need do to a bit more work (at least the first time around). You may wish to Subscribe to a public policy list, Create your own own policy and rules and Enabling built-in protections.

Giving Draupnir permissions to do its job

For Draupnir to do its job, you need to give it permissions in rooms it's protecting. This involves giving it an Administrator power level.

We recommend setting this power level as soon as the bot joins your room (and before you create new rules), so that it can apply rules as soon as they are available. If the bot is under-privileged, it may fail to apply protections and may not retry for a while (or until your restart it).

Subscribing to a public policy list

We recommend subscribing to a public policy list using the watch command.

Polcy lists are maintained in Matrix rooms. A popular policy list is maintained in the public #community-moderation-effort-bl:neko.dev room.

You can tell Draupnir to subscribe to it by sending the following command to the Management Room: !draupnir watch #community-moderation-effort-bl:neko.dev

Creating your own policy lists and rules

We also recommend creating your own policy lists with the list create command.

You can do so by sending the following command to the Management Room: !draupnir list create my-bans my-bans-bl. This will create a policy list having a name (shortcode) of my-bans and stored in a public #my-bans-bl:example.com room on your server. As soon as you run this command, the bot will invite you to the policy list room.

A policy list does nothing by itself, so the next step is adding some rules to your policy list. Policies target a so-called entity (one of: user, room or server). These entities are mentioned on the policy lists documentation page and in the Matrix Spec here.

The simplest and most useful entity to target is user. Below are a few examples using the ban command and targeting users.

To create rules, you run commands in the Management Room (not in the policy list room).

• (ban a single user on a given homeserver): !draupnir ban @charles:example.com my-bans Rude to others
• (ban all users on a given homeserver by using a wildcard): !draupnir ban @*:example.org my-bans Spam server - all users are fake

As a result of running these commands, you may observe:

• Draupnir creating m.policy.rule.user state events in the #my-bans-bl:example.com room on your server
• applying these rules against all rooms that Draupnir is an Administrator in

You can undo bans with the unban command.

Enabling built-in protections

You can also turn on various built-in protections like JoinWaveShortCircuit ("If X amount of users join in Y time, set the room to invite-only").

To see which protections are available and which are enabled, send a !draupnir protections command to the Management Room.

To see the configuration options for a given protection, send a !draupnir config get PROTECTION_NAME (e.g. !draupnir config get JoinWaveShortCircuit).

To set a specific option for a given protection, send a command like this: !draupnir config set PROTECTION_NAME.OPTION VALUE (e.g. !draupnir config set JoinWaveShortCircuit.timescaleMinutes 30).

To enable a given protection, send a command like this: !draupnir enable PROTECTION_NAME (e.g. !draupnir enable JoinWaveShortCircuit).

To disable a given protection, send a command like this: !draupnir disable PROTECTION_NAME (e.g. !draupnir disable JoinWaveShortCircuit).