Empty admin rooms should be discarded or unused

[AndrewFerr]

If a user leaves their admin room, Hookshot continues to use it for posting URLs generated by !hookshot webhook. Since admin rooms are typically invite-only DMs, the user will never be able rejoin the room after leaving it, and will never be able to see those messages.

To prevent posting messages in inaccessible admin rooms, Hookshot should either leave empty admin rooms (on startup or in response to the user leaving), or should invite the user back to an admin room when posting a new message in it. My preference is the former, because it prevents Hookshot's room list from slowly growing larger and larger.

[michielappelman]

Oh no. I didn't realize this was a thing, so I have indeed left the initial room created by Hookshot and now cannot set up additional webhooks.

Is there a workaround available? I took a look at the info coming back from the Provisioning API but that also doesn't include the Webhook URL, nor do I seem to be able to set up a new Admin Room.

[AndrewFerr]

If you're running your own Hookshot instance, you can do this:

• Invite the Hookshot bot to a new DM.
• Get the room ID of the old admin room.
  • The easiest way to find it is to look through your browser history.
  • Otherwise, you can use this Bash script to find it, using Hookshot's appservice registration token as AS_TOKEN:

AS_TOKEN=$(awk '/as_token/ {print $2}' registration.yml)
HOMESERVER_URL='http://<your_host_and_port_here>'
for ROOM in $(curl -s -H "Authorization: Bearer $AS_TOKEN" "${HOMESERVER_URL}/_matrix/client/v3/joined_rooms" | jq -r '.joined_rooms[]'); do
    if [[ $(curl -s -H "Authorization: Bearer $AS_TOKEN" "${HOMESERVER_URL}/_matrix/client/v3/user/@hookshot:synapse-hookshot.testlocal/rooms/${ROOM}/account_data/uk.half-shot.matrix-hookshot.github.room" | jq '.admin_user') != null ]]; then
        echo $ROOM
    fi
done

• Manually make the Hookshot bot leave the old admin room by either:
  • using the Synapse Admin API to delete that room: https://matrix-org.github.io/synapse/latest/admin_api/rooms.html#delete-room-api
  • using the Client-Server API (with Hookshot's appservice registration token as the authentication token) to make the Hookshot bot leave that room: https://spec.matrix.org/latest/client-server-api/#post_matrixclientv3roomsroomidleave
• Restart Hookshot

This worked for me in a local test instance.

[michielappelman]

Thanks a million, that worked perfectly. I used Synapse Admin to combine step 2 and 3, where I found the room with the lone Hookshot in there and deleted it from the list. After a restart of hookshot (actually the whole Matrix environment), the Hookshot bot is now indeed sharing its secrets with me once again. 🙏