feat(backend): PgBouncer/PgCat pooler 대응 (read-only 분리)

backend/app/api/connections.py

@@ -8,33 +8,38 @@
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.auth import CurrentUser, get_current_user
-from app.db import get_session
+from app.db import get_read_session, get_session
 from app.models import DbConnection
 from app.permissions import require_project_member
 from app.schemas import ConnectionCreateIn, ConnectionOut
 from app.security import encrypt_text
 from app.sanitize import sanitize_for_storage
 
-
 router = APIRouter(prefix="/api/connections", tags=["connections"])
 
 
-@router.get("/by-project/{project_space_uuid}", response_model=list[ConnectionOut])
+@router.get(
+    "/by-project/{project_space_uuid}", response_model=list[ConnectionOut]
+)
 async def list_connections(
     project_space_uuid: uuid.UUID,
     user: CurrentUser = Depends(get_current_user),
-    session: AsyncSession = Depends(get_session),
+    session: AsyncSession = Depends(get_read_session),
 ) -> list[ConnectionOut]:
     """List DB connections for a project."""
-    await require_project_member(session, project_space_uuid, user.user_account_uuid)
+    await require_project_member(
+        session, project_space_uuid, user.user_account_uuid
+    )
     rows = await session.execute(
         select(DbConnection)
         .where(DbConnection.project_space_uuid == project_space_uuid)
         .order_by(DbConnection.created_at.desc())
     )
     cons = rows.scalars().all()
     return [
-        ConnectionOut(db_connection_uuid=c.db_connection_uuid, conn_name=c.conn_name)
+        ConnectionOut(
+            db_connection_uuid=c.db_connection_uuid, conn_name=c.conn_name
+        )
         for c in cons
     ]
 
@@ -47,7 +52,9 @@ async def create_connection(
     session: AsyncSession = Depends(get_session),
 ) -> ConnectionOut:
     """Create a DB connection for a project (encrypt DSN at rest)."""
-    await require_project_member(session, project_space_uuid, user.user_account_uuid)
+    await require_project_member(
+        session, project_space_uuid, user.user_account_uuid
+    )
     encrypted = encrypt_text(str(sanitize_for_storage(body.dsn)))
     c = DbConnection(
         db_connection_uuid=uuid.uuid4(),
@@ -60,4 +67,6 @@ async def create_connection(
     )
     session.add(c)
     await session.commit()
-    return ConnectionOut(db_connection_uuid=c.db_connection_uuid, conn_name=c.conn_name)
+    return ConnectionOut(
+        db_connection_uuid=c.db_connection_uuid, conn_name=c.conn_name
+    )

backend/app/api/projects.py

@@ -9,7 +9,7 @@
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.auth import CurrentUser, get_current_user
-from app.db import get_session
+from app.db import get_read_session, get_session
 from app.models import ProjectMember, ProjectSpace, UserAccount
 from app.schemas import (
     ProjectCreateIn,
@@ -19,14 +19,13 @@
 )
 from app.sanitize import sanitize_for_storage
 
-
 router = APIRouter(prefix="/api/projects", tags=["projects"])
 
 
 @router.get("", response_model=list[ProjectOut])
 async def list_projects(
     user: CurrentUser = Depends(get_current_user),
-    session: AsyncSession = Depends(get_session),
+    session: AsyncSession = Depends(get_read_session),
 ) -> list[ProjectOut]:
     """List projects that the current user is a member of."""
     rows = await session.execute(
@@ -40,7 +39,9 @@ async def list_projects(
     )
     projects = rows.scalars().all()
     return [
-        ProjectOut(project_space_uuid=p.project_space_uuid, project_name=p.project_name)
+        ProjectOut(
+            project_space_uuid=p.project_space_uuid, project_name=p.project_name
+        )
         for p in projects
     ]
 
@@ -74,11 +75,13 @@ async def create_project(
     )
 
 
-@router.get("/{project_space_uuid}/members", response_model=list[ProjectMemberOut])
+@router.get(
+    "/{project_space_uuid}/members", response_model=list[ProjectMemberOut]
+)
 async def list_project_members(
     project_space_uuid: uuid.UUID,
     user: CurrentUser = Depends(get_current_user),
-    session: AsyncSession = Depends(get_session),
+    session: AsyncSession = Depends(get_read_session),
 ) -> list[ProjectMemberOut]:
     """List members of a project (MVP: any member can view)."""
     # owner/editor/viewer 모두 멤버 조회 가능(MVP)
@@ -164,7 +167,8 @@ async def add_project_member(
     if existing_role == "owner":
         # Avoid leaving project without an owner via this endpoint.
         raise HTTPException(
-            status_code=400, detail="cannot change owner role via invite endpoint"
+            status_code=400,
+            detail="cannot change owner role via invite endpoint",
         )
 
     # Race-safe upsert on composite PK.

backend/app/api/share.py

@@ -9,10 +9,14 @@
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.auth import CurrentUser, get_current_user
-from app.db import get_session
+from app.db import get_read_session, get_session
 from app.ddl.export import snapshot_json_to_sql
-from app.models import ProjectMember, SchemaSnapshot, SchemaSnapshotData, ShareLink
-
+from app.models import (
+    ProjectMember,
+    SchemaSnapshot,
+    SchemaSnapshotData,
+    ShareLink,
+)
 
 router = APIRouter(prefix="/api", tags=["share"])
 
@@ -54,7 +58,7 @@ async def create_share_link(
 @router.get("/share/{share_link_uuid}")
 async def get_share_link_info(
     share_link_uuid: uuid.UUID,
-    session: AsyncSession = Depends(get_session),
+    session: AsyncSession = Depends(get_read_session),
 ) -> dict:
     """Return share link metadata and recent snapshots."""
     link = await session.get(ShareLink, share_link_uuid)
@@ -91,7 +95,7 @@ async def get_share_link_info(
 async def get_shared_snapshot(
     share_link_uuid: uuid.UUID,
     schema_snapshot_uuid: uuid.UUID,
-    session: AsyncSession = Depends(get_session),
+    session: AsyncSession = Depends(get_read_session),
 ) -> dict:
     """Return a snapshot via a share link (no auth)."""
     link = await session.get(ShareLink, share_link_uuid)
@@ -123,7 +127,7 @@ async def get_shared_snapshot(
 async def export_shared_snapshot_sql(
     share_link_uuid: uuid.UUID,
     schema_snapshot_uuid: uuid.UUID,
-    session: AsyncSession = Depends(get_session),
+    session: AsyncSession = Depends(get_read_session),
 ) -> str:
     """Export a shared snapshot as SQL via a share link."""
     link = await session.get(ShareLink, share_link_uuid)

backend/app/api/snapshots.py

@@ -9,13 +9,17 @@
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.auth import CurrentUser, get_current_user
-from app.db import get_session
-from app.models import DbConnection, JobQueue, SchemaSnapshot, SchemaSnapshotData
+from app.db import get_read_session, get_session
+from app.models import (
+    DbConnection,
+    JobQueue,
+    SchemaSnapshot,
+    SchemaSnapshotData,
+)
 from app.permissions import require_project_member
 from app.schemas import SnapshotCreateIn, SnapshotDetailOut, SnapshotOut
 from app.ddl.export import snapshot_json_to_sql
 
-
 router = APIRouter(prefix="/api/snapshots", tags=["snapshots"])
 
 
@@ -27,7 +31,9 @@ async def create_snapshot(
     session: AsyncSession = Depends(get_session),
 ) -> SnapshotOut:
     """Create a schema snapshot job for a project connection."""
-    await require_project_member(session, project_space_uuid, user.user_account_uuid)
+    await require_project_member(
+        session, project_space_uuid, user.user_account_uuid
+    )
 
     # Ensure connection belongs to this project
     conn = await session.get(DbConnection, body.db_connection_uuid)
@@ -77,7 +83,7 @@ async def create_snapshot(
 async def get_snapshot(
     schema_snapshot_uuid: uuid.UUID,
     user: CurrentUser = Depends(get_current_user),
-    session: AsyncSession = Depends(get_session),
+    session: AsyncSession = Depends(get_read_session),
 ) -> SnapshotDetailOut:
     """Get a snapshot's status and (if present) captured JSON."""
     snap = await session.get(SchemaSnapshot, schema_snapshot_uuid)
@@ -102,11 +108,13 @@ async def get_snapshot(
     )
 
 
-@router.get("/{schema_snapshot_uuid}/export.sql", response_class=PlainTextResponse)
+@router.get(
+    "/{schema_snapshot_uuid}/export.sql", response_class=PlainTextResponse
+)
 async def export_snapshot_sql(
     schema_snapshot_uuid: uuid.UUID,
     user: CurrentUser = Depends(get_current_user),
-    session: AsyncSession = Depends(get_session),
+    session: AsyncSession = Depends(get_read_session),
 ) -> str:
     """Export a snapshot as PostgreSQL DDL (best-effort)."""
     snap = await session.get(SchemaSnapshot, schema_snapshot_uuid)
@@ -121,14 +129,18 @@ async def export_snapshot_sql(
     return snapshot_json_to_sql(data.snapshot_json)
 
 
-@router.get("/by-project/{project_space_uuid}", response_model=list[SnapshotOut])
+@router.get(
+    "/by-project/{project_space_uuid}", response_model=list[SnapshotOut]
+)
 async def list_snapshots(
     project_space_uuid: uuid.UUID,
     user: CurrentUser = Depends(get_current_user),
-    session: AsyncSession = Depends(get_session),
+    session: AsyncSession = Depends(get_read_session),
 ) -> list[SnapshotOut]:
     """List snapshots for a project."""
-    await require_project_member(session, project_space_uuid, user.user_account_uuid)
+    await require_project_member(
+        session, project_space_uuid, user.user_account_uuid
+    )
     rows = await session.execute(
         select(SchemaSnapshot)
         .where(SchemaSnapshot.project_space_uuid == project_space_uuid)