raphexion/minimonkey repository overview
Mini Monkey (pre-alpha)
Mini Monkey is a minimal message routing system. Considerably smaller and simpler than MQTT. Like other message brokers (RabbitMQ, EMQX, VerneMQ), Mini Monkey is implemented in Erlang.
Quick Start
docker run -d -p 1773:1773 -e god_token=myToken raphexion/minimonkey
Clients
Project Plan
- Streamline debug/error messages
- Add benchmark tests
- Add more tests concerning permissions
- Add more examples in README
- Death Message
Three perspectives
When designing Mini Monkey we need to focus on our three main uses-cases:
- A embedded device produces data and is remotely controllable.
- A controller is cosuming data from one or more producers and send control messages.
- An administrator configures (programmaticially) who can publish/subscribe.
Design decisions
Mini Monkey is a publish / subscribe broker than only support routing keys (called rooms). Especially it does not implement topics.
Mini Monkey only cares about routing blobs. Especially it does not use JSON / Protocol-buffers or other serialization.
Mini Monkey is designed around small payloads.
Mini Monkey is desgined to be very simple and concise. The goal is to reach feature-completion fast and leave as much as possible outside the broker. The protocol and architecture should be so easy that anyone can implement a client in under and hour.
Mini Monkey uses stateful connections where previous commands affect future commands. The reasons is to keep all payloads small.
Bootstrap and the God Token
Then Mini Monkey starts it will read the environment variable god_token. The purpose is to have one token that can bootstrap the broker. This token can be used to provision the broker and the routing keys (rooms).
| Variable | Comment |
|---|---|
| god_token | A token that has all rights |
Port
Mini Monkey only uses one port 1773. Connections are made over TCP/IP.
| Port | Comment |
|---|---|
| 1773 | Controllers, Devices and Administrators |
Death Message
Sometimes it is good to communicate when a user disappears. It is therefore (not implemented yet) to set a message, that will be delivered if the user disconnects unexpected.
Protocal
All messages, both to and from the server follow a trivial binary protocol.
| Size | Comment |
|---|---|
| 1 bit | Big endian size? |
| 7 bits | Function Code |
| 2 bytes | Payload size |
| N bytes | Optional payload |
Function Codes
| Code | Comment | Payload meaning |
|---|---|---|
| 0x00 | Reseved for future use | |
| 0x01 | Authenticate with token | Token |
| 0x02 | Enter room (persistent until changed or reconnect) | Room |
| 0x03 | Publish binary payload | Published data |
| 0x04 | Subscribe to current room | Tag |
| 0x10 | Add admin permissions for token | Additional admin token in room |
| 0x11 | Revoke admin permissions for token | Token to be revoked |
| 0x12 | Add publish permissions for token | Additional publish token in room |
| 0x13 | Revoke publish permissions for token | Token to be revoked |
| 0x14 | Add subscription permissions for token | Additional subs. token in room |
| 0x15 | Revoke subscription permissions for token | Token to be revoked |
| 0x16 | Add login | Additional token that can login |
| 0x17 | Revoke login | Revoke a token for login |
| 0x20 | Set death message payload | Data that is sent when disconnect |
| 0x21 | Set death message room | Room where the messages is published |
| 0x22 | Enable death message | |
| 0x23 | Disable death message | |
| 0x30 | Forward messages in this room to another room | Destiantion room for forward |
| 0x31 | Unforward message in this room to anther room | Destionation room for un-forward |
| 0x7E | Error message | Message |
| 0x7F | Debug message | Message |
Examples
A client logins in and publish 3 messages:
| Purpose | Bytes (little endian) | Optional Payload | Comment |
|---|---|---|---|
| Auth with token | 0x01 0x04 0x00 | 0x41 0x42 0x43 0x44 | Token: ABCD |
| Enter room | 0x02 0x03 0x00 | 0x51 0x52 0x53 | Key: QRS |
| Publish | 0x03 0x04 0x00 | 0x01 0x02 0x03 0x04 0x05 | Binary payload |
| Publish | 0x03 0x02 0x00 | 0xFF 0xEE | Binary payload |
| Pick another | 0x02 0x04 0x00 | 0x51 0x52 0x53 0x032 | Key: QRS2 |
| Publish | 0x03 0x01 0x00 | 0xAB | Binary payload |
Tag summary
Content type
Image
Digest
Size
26.1 MB
Last updated
about 7 years ago
docker pull raphexion/minimonkey