Supported MySQL Changes Listening

Dockerfile

@@ -1,23 +1,35 @@
-FROM python:3.12-slim
+FROM python:3.12.9-alpine3.21
 
+# FROM python:3.12-slim
+
+# Set environment variables
+ENV PYTHONDONTWRITEBYTECODE=1
+ENV PYTHONUNBUFFERED=1
+
+# Set the working directory inside the container
 WORKDIR /app
 
-RUN apt-get update && apt-get install -y \
+# Install system dependencies required for MySQL and other libraries
-    build-essential \
+# RUN apt-get update && apt-get install -y \
-    curl \
+#     default-libmysqlclient-dev \
-    software-properties-common \
+#     build-essential \
-    git \
+#     && rm -rf /var/lib/apt/lists/*
+
+# Copy the requirements file into the container
+COPY files/requirements.txt .
+
+# Install Python dependencies
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Clone the Git repository
+RUN apt-get update && apt-get install -y git \
+    && git clone https://gitea.abdulhade.com/abdulhade/db-middleware.git . \
+    && apt-get remove -y git \
+    && apt-get autoremove -y \
     && rm -rf /var/lib/apt/lists/*
 
-# RUN git clone https://github.com/streamlit/streamlit-example.git .
+# Expose port 8080 for the FastAPI application
-COPY requirements.txt .
+EXPOSE 8080
 
-RUN pip3 install -r requirements.txt
+# Command to run the FastAPI application
-
+CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8080"]
-# COPY . .
-
-EXPOSE 8333
-
-# HEALTHCHECK CMD curl --fail http://localhost:8501/_stcore/health
-
-# ENTRYPOINT ["streamlit", "run", "main.py", "--server.port=8501", "--server.address=0.0.0.0"]

app/operations.py

@@ -1,4 +1,5 @@
-from fastapi import WebSocket
+import asyncio, time, decimal, datetime
+from fastapi import WebSocket, WebSocketDisconnect, WebSocketException
 from fastapi.routing import APIRouter
 from fastapi.responses import StreamingResponse
 from typing_extensions import Annotated
@@ -17,9 +18,12 @@ from core.exceptions import (
     CursorNotFound,
 )
 from dbs import mysql
+from utils.binlog import changes_queue, queue
 
 router = APIRouter()
 
+database_changes_active_websocket: WebSocket | None = None
+
 
 @router.post("/execute", dependencies=[Depends(get_current_user)])
 async def execute_select(
@@ -97,7 +101,7 @@ async def server_side_events_stream_cursor(
             result = await fetch_cursor(cursor_id=cursor_id, page_size=page_size)
 
             serialized_result = result.model_dump_json()
-            yield f"data: {serialized_result}\n\n"  # Format as Server-Sent Event (SSE)
+            yield f"data: {serialized_result}\n\n"
             if result.cursor.is_closed:
                 break
 
@@ -119,7 +123,7 @@ async def websocket_stream_cursor(
     if user is None:
         await websocket.close(reason="Invalid credentials", code=1008)
         return
-    
+
     cached_cursor = mysql.cached_cursors.get(cursor_id, None)
     if cached_cursor is None:
         e = CursorNotFound()
@@ -136,3 +140,69 @@ async def websocket_stream_cursor(
         if result.cursor.is_closed:
             break
     await websocket.close(reason="Done")
+
+
+@router.websocket("/databases_changes")
+async def websocket_endpoint(
+    websocket: WebSocket,
+    db=Depends(get_db),
+):
+    global database_changes_active_websocket
+
+    await websocket.accept()
+
+    api_key = websocket.headers.get("Authorization")
+    user = await get_user_from_api_key(db=db, api_key=api_key)
+    if user is None:
+        await websocket.close(reason="Invalid credentials", code=1008)
+        return
+
+    if database_changes_active_websocket:
+        try:
+            await database_changes_active_websocket.close(
+                code=1001, reason="New connection established"
+            )
+        except Exception as e:
+            print(e)
+
+    database_changes_active_websocket = websocket
+    await websocket.send_json({"message":"status", "status":"Accepted."})
+
+    try:
+        await feed_databases_changes_ws(websocket=websocket)
+    except WebSocketDisconnect:
+        print('Closed websocket.')
+
+def serialize_list(l:list):
+    serialized = []
+    for value in l:
+        if isinstance(value, str | int | None | float):
+            serialized.append(str(value))
+        elif isinstance(value, decimal.Decimal):
+            serialized.append(float(value))
+        elif isinstance(value, datetime.date):
+            serialized.append(value.strftime("%Y-%m-%d"))
+        else:
+            serialized.append(str(value))
+    return serialized
+
+
+
+async def feed_databases_changes_ws(websocket:WebSocket):
+
+    last_update = 0
+    while True:
+        try:
+            change = changes_queue.get_nowait()
+            if change.action == 'UPDATE':
+                change.after_values = serialize_list(change.after_values)
+                change.before_values = serialize_list(change.before_values)
+            else:
+                change.values = serialize_list(change.values)
+            await websocket.send_json({"message": "change", 'change': change.model_dump()})
+        except queue.Empty:
+            if last_update + 10 < time.time():
+                await websocket.send_json({"message":"status", "status":"Alive."})
+                last_update = time.time()
+            await asyncio.sleep(1)
+            continue

core/enums.py

@@ -1,8 +1,10 @@
 import enum
 
+
 class ConnectionTypes(str, enum.Enum):
     mysql = "mysql"
-    postgresql = 'postgresql'
+    postgresql = "postgresql"
+
 
 class UserRole(enum.Enum):
     admin = "admin"
@@ -22,6 +24,13 @@ class FilterOperator(str, enum.Enum):
     is_null = "IS NULL"
     is_not_null = "IS NOT NULL"
 
+
 class SortOrder(str, enum.Enum):
     asc = "ASC"
-    desc = "DESC"
+    desc = "DESC"
+
+
+class DBUpdatesActions(str, enum.Enum):
+    insert = "INSERT"
+    update = "UPDATE"
+    delete = "DELETE"

data/schemas.py

@@ -2,7 +2,13 @@ import re
 from typing import Union, List, Optional, Literal, Any
 from typing_extensions import Annotated
 from pydantic import BaseModel, Field, field_validator, ValidationInfo, UUID4
-from core.enums import ConnectionTypes, UserRole, FilterOperator, SortOrder
+from core.enums import (
+    ConnectionTypes,
+    UserRole,
+    FilterOperator,
+    SortOrder,
+    DBUpdatesActions,
+)
 from core.exceptions import QueryValidationError
 
 
@@ -189,6 +195,7 @@ class CachedCursorOut(BaseModel):
     has_more: bool
     close_at: int
     ttl: int
+
     class Config:
         from_attributes = True
 
@@ -196,3 +203,25 @@ class CachedCursorOut(BaseModel):
 class SelectResult(BaseModel):
     cursor: CachedCursorOut
     results: SelectResultData | None
+
+
+class ConnectionChangeBase(BaseModel):
+    connection_id: int
+    action: DBUpdatesActions
+    table: str
+
+
+class ConnectionChangeInsert(ConnectionChangeBase):
+    action: DBUpdatesActions = DBUpdatesActions.insert
+    values: list[Any]
+
+
+class ConnectionChangeDelete(ConnectionChangeBase):
+    action: DBUpdatesActions = DBUpdatesActions.delete
+    values: list[Any]
+
+
+class ConnectionChangeUpdate(ConnectionChangeBase):
+    action: DBUpdatesActions = DBUpdatesActions.update
+    before_values: list[Any]
+    after_values: list[Any]

dbs/mysql.py

@@ -59,7 +59,6 @@ async def cached_cursors_cleaner():
 async def pool_creator(connection: Connection, minsize=5, maxsize=10):
 
     return await aiomysql.create_pool(
-        # **DB_CONFIG,
         host=connection.host,
         user=connection.username,
         password=connection.password,

main.py

@@ -2,24 +2,16 @@ import asyncio
 from contextlib import asynccontextmanager
 from fastapi import FastAPI
 from app import api_router
-from utils.scripts import pools_creator, pools_destroy, db_startup, cursors_closer
+from utils.scripts import startup, shutdown
-from dbs import mysql
+
 
 
 @asynccontextmanager
 async def lifespan(app: FastAPI):
-    await pools_creator()
+    await startup()
-    mysql.cached_cursors_cleaner_task = asyncio.create_task(mysql.cached_cursors_cleaner())
-    
     yield
-
+    await shutdown()
-    mysql.cached_cursors_cleaner_task.cancel()
+    
-    try:
-        await mysql.cached_cursors_cleaner_task
-    except asyncio.CancelledError:
-        print('Closed cached_cursors_cleaner_task')
-    await cursors_closer()
-    await pools_destroy()
 
 
 app = FastAPI(lifespan=lifespan)

requirements.txt

@@ -1,8 +0,0 @@
-fastapi[all]
-uvicorn
-aiomysql
-websockets
-pydantic
-python-dotenv
-aiosqlite
-sqlalchemy

utils/binlog.py

@@ -0,0 +1,120 @@
+from data.schemas import (
+    Connection,
+    ConnectionChangeUpdate,
+    ConnectionChangeDelete,
+    ConnectionChangeInsert,
+)
+from pymysqlreplication import BinLogStreamReader
+from pymysqlreplication.row_event import (
+    WriteRowsEvent,
+    UpdateRowsEvent,
+    DeleteRowsEvent,
+)
+
+import threading, asyncio, time
+
+import queue
+
+events_threads: list[threading.Thread] = []
+streams: list[BinLogStreamReader] = []
+stop_flag = threading.Event()
+
+changes_queue: queue.Queue[
+    ConnectionChangeUpdate,
+    ConnectionChangeDelete,
+    ConnectionChangeInsert,
+] = queue.Queue()
+
+
+def initiate_stream(connection: Connection) -> BinLogStreamReader:
+    return BinLogStreamReader(
+        connection_settings={
+            "host": connection.host,
+            "port": connection.port,
+            "user": connection.username,
+            "passwd": connection.password,
+        },
+        server_id=100,  # Unique ID for this client
+        blocking=False,  # Wait for new events
+        resume_stream=True,  # Resume from the last position
+        only_events=[
+            WriteRowsEvent,
+            UpdateRowsEvent,
+            DeleteRowsEvent,
+        ],  # Only capture these events
+    )
+
+
+def events_generator(stream: BinLogStreamReader, connection_id: int):
+    while not stop_flag.is_set():
+        for binlog_event in stream:
+            for row in binlog_event.rows:
+                if isinstance(binlog_event, WriteRowsEvent):
+                    changes_queue.put(
+                        ConnectionChangeInsert(
+                            connection_id=connection_id,
+                            table=binlog_event.table,
+                            values=list(row["values"].values()),
+                        )
+                    )
+                elif isinstance(binlog_event, UpdateRowsEvent):
+                    changes_queue.put(
+                        ConnectionChangeUpdate(
+                            connection_id=connection_id,
+                            table=binlog_event.table,
+                            before_values=list(row["before_values"].values()),
+                            after_values=list(row["before_values"].values()),
+                        )
+                    )
+
+                elif isinstance(binlog_event, DeleteRowsEvent):
+                    changes_queue.put(
+                        ConnectionChangeDelete(
+                            connection_id=connection_id,
+                            table=binlog_event.table,
+                            values=list(row["values"].values()),
+                        )
+                    )
+        time.sleep(1)
+
+
+async def process_updates():
+    while True:
+        try:
+            change = changes_queue.get(block=False)
+            print(f"Processing update: {change.model_dump()}")
+        except queue.Empty:
+            await asyncio.sleep(0.5)
+
+
+def start_listeners(connections: list[Connection]):
+    global events_threads, streams
+    for connection in connections:
+        stream = initiate_stream(connection=connection)
+        streams.append(stream)
+
+    for stream, connection in zip(streams, connections):
+        binlog_thread = threading.Thread(
+            target=events_generator,
+            daemon=True,
+            kwargs={"stream": stream, "connection_id": connection.id},
+        )
+        binlog_thread.start()
+        events_threads.append(binlog_thread)
+    print("Created listeners")
+
+
+def destroy():
+    stop_flag.set()
+    for thread in events_threads:
+        if thread.is_alive():
+            thread.join(timeout=5)
+            if thread.is_alive():
+                print(f"Thread {thread.name} did not stop gracefully")
+
+    events_threads.clear()
+    for stream in streams:
+        stream.close()
+
+    stop_flag.clear()
+    print("Closed listeners")

utils/scripts.py

@@ -1,14 +1,42 @@
 # add_user.py
 
-import asyncio, logging
+import asyncio, logging, pymysql
 import secrets
 from sqlalchemy.future import select
-from sqlalchemy.exc import IntegrityError
-from getpass import getpass
 from data.db import engine, SessionLocal
 from data.models import Base, User, UserRole
 
 
+async def startup():
+    from dbs import mysql    
+    from app.operations import feed_databases_changes_ws
+    await pools_creator()
+    await mysql_streams_listeners_creator()
+    mysql.cached_cursors_cleaner_task = asyncio.create_task(mysql.cached_cursors_cleaner())
+    
+
+async def shutdown():
+    from dbs import mysql
+    mysql.cached_cursors_cleaner_task.cancel()
+    try:
+        await mysql.cached_cursors_cleaner_task
+    except asyncio.CancelledError:
+        print('Closed cached_cursors_cleaner_task')
+    await cursors_closer()
+    await pools_destroy()
+
+    from utils.binlog import destroy
+    destroy()
+    
+
+async def mysql_streams_listeners_creator():
+    from data.crud import read_all_connections
+    async with SessionLocal() as db:
+        connections = await read_all_connections(db=db)
+    
+    from utils.binlog import start_listeners
+    start_listeners(connections=connections)
+
 async def pools_creator():
     from data.crud import read_all_connections
     from dbs import mysql
@@ -17,7 +45,11 @@ async def pools_creator():
         connections = await read_all_connections(db=db)
 
     for connection in connections:
-        mysql.pools[connection.id] = await mysql.pool_creator(connection=connection)
+        try:
+            mysql.pools[connection.id] = await mysql.pool_creator(connection=connection)
+        except pymysql.err.OperationalError as e:
+            print(e)
+        
     logging.info(msg='Created Pools')
 
 async def cursors_closer():