Wess: WebAssembly Service System

tl;dr

Just for Learn!!!

• Store your WebAssembly
• Run your WebAssembly

Road Map

Feature	Status	Priority
Docs about how to execute a function	⏰	🔥
Import another wasm module into wasm functions	⏰	😴
Give access to syscall into wasm functions	⏰	😴
Make wasm functions with persisted memory state (store/retrieve)	⏰	😴
Run Wasm functions multiple params (Array) -> (Array)	⏰	😴
CRUD ops Wasm module	✅	✅
Run Wasm functions without params () -> i32	✅	✅
Run Wasm functions with one params (i32) -> i32	✅	✅
Run Wasm functions multiple params (i32) -> i32	✅	✅
Run Wasm functions multiple params (i32/i64/f32/f64) -> (i32/i64/f32/f64)	✅	✅
Logging module	✅	✅
Read/Write ops on RocksDB	✅	✅
Export metrics with Prometheus	✅	✅
Reading metrics with Grafana	✅	✅
Load tests with k6	✅	✅
Behave tests with Behave	✅	✅
Wasm Examples	✅	✅

How to play?

Start with

cargo run

Upload a Wasm file

• You need convert your wasm to bytes array, see how here

curl -X POST http://localhost:80 -H "Content-Type: application/json" -d '{
  "wasm": [ 0,97,115,109,1,0,0,0,1,5,1,96,0,1,127,3,2,1,0,5,3,1,0,16,7,23,2,6,109,101,109,111,114,121,2,0,10,116,104,101,95,97,110,115,119,101,114,0,0,10,6,1,4,0,65,42,11,0,35,4,110,97,109,101,1,28,1,0,25,116,104,101,95,97,110,115,119,101,114,46,99,111,109,109,97,110,100,95,101,120,112,111,114,116,0,104,9,112,114,111,100,117,99,101,114,115,2,8,108,97,110,103,117,97,103,101,1,4,82,117,115,116,0,12,112,114,111,99,101,115,115,101,100,45,98,121,3,5,114,117,115,116,99,29,49,46,54,56,46,49,32,40,56,52,54,48,99,97,56,50,51,32,50,48,50,51,45,48,51,45,50,48,41,5,99,108,97,110,103,6,49,53,46,48,46,54,6,119,97,108,114,117,115,6,48,46,49,57,46,48,0,30,15,116,97,114,103,101,116,95,102,101,97,116,117,114,101,115,1,43,11,98,117,108,107,45,109,101,109,111,114,121 ],
  "metadata": {
    "functionName": "the_answer",
    "returnType": [
      "I32"
    ],
    "args": []
  }
}'
>>> {"message":{"id":"b38ed019-45be-42c1-9bd8-2b781b91d082"}}

• You can update your wasm using PUT

curl -X PUT http://localhost:80/b38ed019-45be-42c1-9bd8-2b781b91d082
  -H "Content-Type: application/json" -d '{
  "wasm": [ 99, 99, 99, 99 ],
  "metadata": {
    "functionName": "new_function",
    "returnType": [
      "I32"
    ],
    "args": []
  }
}'
>>> {"message":{"id":"b38ed019-45be-42c1-9bd8-2b781b91d082"}}

Run your Wasm

curl -X POST http://localhost:80/a180761b-c9d5-482f-a4df-680443ee1cf2 -H "Content-Type: application/json" -d '[]'
>>> {"message":[42]}

How it Works?

Read Ops

1. receive a id
2. validate it (uuid-v4)
3. and ask Reader about the wasm module
4. respond 200 | 400 | 404 | 500

Write Ops

1. receive a json
2. validate it (wasm module)
3. create a new uuid
4. respond 202 | 400 | 404 | 500
5. [Async after return] send the json to Writer
6. [Async after return] Writer perform op (Create | Update | delete)

Run Ops

1. receive a json
2. validate it (params and uuid-v4)
3. retrieve wasm module from Reader
4. send wasm module to Runner to execute wasm function
5. respond 200 | 400 | 404 | 500

Channels

• Encapsulates validated data (like a DTO) sends it in a queue to the Worker responsible for the process
• The messages sent are called Jobs:

pub enum WriteOps {
    Create,
    Update,
    Delete,
}

pub struct WriteJob {
    pub write_req: Option<WasmModule>,
    pub write_type: WriteOps,
    pub id: String,
}

#[derive(Debug)]
pub struct ReadJob {
    pub responder: Sender<ReadResponse>,
    pub id: String,
}

#[derive(Debug)]
pub struct RunJob {
    pub responder: Sender<RunResponse>,
    pub args: Vec<Value>,
    pub id: String,
}

Workers

Writer

• Don't respond anything, just write

1. Receive a WriteJob by channel
2. Performs op into database (Rocksdb)

Reader

• Just read and respond

1. Receive a ReadJob by channel
2. Try found id in Cache
3. Try found id in database (Rocksdb)
4. Send WasmModule by channel

Runner

• Execute function and return the result

1. Receive a RunJob by channel
2. Build Engine to try exec function
3. Send result of computation by channel to RunOps
4. Send result of computation by channel to Writter (stateful call) [Not implemented]