initial commit

.gitignore

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+.mypy_cache/
+__pycache__/

README.md

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+feature che vorremmo:
+ - interfaccia che mostra in grande dei numeri
+ - possibilità di controllo da tastiera, ma magari anche in altri modi
+ - possibilità di sapere lo stato corrente (HTTP)
+ - notifiche push (websocket)

pizzicore/Dockerfile

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+FROM python:3.7
+
+ENV DEBIAN_FRONTEND=noninteractive
+
+WORKDIR /src
+
+RUN apt-get update
+
+RUN python -m pip install wheel
+
+COPY requirements.txt /
+RUN python -m pip install -r /requirements.txt
+COPY . /src/
+
+CMD ["uvicorn", "pizzicore:app", "--reload", "--port", "8000", "--host", "0.0.0.0"]

pizzicore/README.md

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+Componente centrale del sistema pizzicaroli. tiene i conti.
+espone HTTP e WebSocket.
+
+Alcune API richiedono autenticazione.
+
+Il docker-compose incluso è solo per comodità di sviluppo, non è strettamente necessario.

pizzicore/docker-compose.yaml

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+version: "3"
+
+services:
+  server:
+    build: .
+    # XXX: prima o poi servirà una qualche /var/lib/ in cui tenere il contatore
+    volumes:
+        - .:/src/
+    ports:
+      - 8000:8000

pizzicore/pizzicore.py

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+import secrets
+from collections import defaultdict
+
+from asyncio.queues import Queue
+from fastapi import FastAPI, WebSocket, HTTPException, Depends, status
+from fastapi.security import HTTPBasic, HTTPBasicCredentials
+from pydantic import BaseModel
+
+
+class Store:
+    def __init__(self, n: int):
+        self.values = {i: 0 for i in range(n)}
+
+    def get(self, key):
+        return self.values[key]
+
+    def incr(self, key):
+        return self.set(key, self.get(key) + 1)
+
+    def set(self, key, value):
+        self.values[key] = value
+        return value
+
+
+class SignalStore(Store):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.registry = defaultdict(list)
+
+    def subscribe(self, key, q):
+        self.registry[key].append(q)
+
+    def _notify(self, key):
+        for queue in self.registry[key]:
+            queue.put_nowait(self.get(key))
+
+    def set(self, key, value):
+        super().set(key, value)
+        self._notify(key)
+
+
+app = FastAPI()
+counter_store = Store(n=1)  # XXX: pesca da file di conf
+security = HTTPBasic()
+
+
+class Value(BaseModel):
+    counter: int
+    value: int
+
+
+def get_current_username(credentials: HTTPBasicCredentials = Depends(security)):
+    # XXX: read user/pass from config
+    correct_username = secrets.compare_digest(credentials.username, "avanti")
+    correct_password = secrets.compare_digest(credentials.password, "prossimo")
+    if not (correct_username and correct_password):
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Incorrect username or password",
+            headers={"WWW-Authenticate": "Basic"},
+        )
+    return "admin"
+
+
+@app.get("/counter/{cid}")
+async def get_value(cid: int):
+    try:
+        val = counter_store.get(cid)
+    except KeyError:
+        raise HTTPException(status_code=404, detail="Item not found")
+    return Value(counter=cid, value=val)
+
+
+@app.post("/counter/{cid}/increment")
+async def increment(cid: int, role: str = Depends(get_current_username)):
+    if role != "admin":
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN)
+    val = counter_store.incr(cid)
+    return Value(counter=cid, value=val)
+
+
+@app.websocket("/ws/counter/{cid}")
+async def websocket_counter(websocket: WebSocket, cid: int):
+    await websocket.accept()
+    # XXX: subscribe to counter
+    while True:
+        # XXX: get notifications
+        val = 1
+        await websocket.send_text(str(val))

pizzicore/requirements.txt

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+fastapi==0.62.0
+uvicorn==0.13.1