[Add] User 생성 API 추가

 - 새로운 도메인 User와 관련된 기능 추가
  - schema, crud, router 코드 생성
  - main.py에 user router 연결
  - 사용자 정보 중복 상황을 다루기 위한 유효성 검사 반영
  - 비밀번호 암호화를 위한 passlib 사용
   - passlib와 bcrypt 간의 버전 문제가 있는 듯 하다.
    - pyca/bcrypt#684
  - 이메일 정보 포맷 확인을 위한 Pydantic 확장
   - pip install pydantic[email]

domain/user/user_crud.py

@@ -0,0 +1,24 @@
+from sqlalchemy.orm import Session
+from passlib.context import CryptContext
+
+from domain.user.user_schema import UserCreate
+from models import User
+
+
+pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
+
+def create_user(db: Session, user_create: UserCreate):
+    db_user = User(
+        username=user_create.username,
+        password=pwd_context.hash(user_create.password1),
+        email=user_create.email
+    )
+
+    db.add(db_user)
+
+    db.commit()
+
+def get_existing_user(db: Session, user_create: UserCreate):
+    return db.query(User).filter(
+        (User.username == user_create.username) | (User.email == user_create.email)
+    ).first()

domain/user/user_router.py

@@ -0,0 +1,18 @@
+from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy.orm import Session
+from starlette import status
+
+from database import get_db
+from domain.user import user_crud, user_schema
+
+
+router = APIRouter(
+    prefix="/api/user",
+)
+
+@router.post("/create", status_code=status.HTTP_204_NO_CONTENT)
+def user_create(_user_create: user_schema.UserCreate, db: Session = Depends(get_db)):
+    user = user_crud.get_existing_user(db, user_create=_user_create)
+    if user:
+        raise HTTPException(status_code=status.HTTP_409_CONFLICT, detail="ALREADY_EXIST_USER")
+    user_crud.create_user(db=db, user_create=_user_create)

domain/user/user_schema.py

@@ -0,0 +1,21 @@
+from pydantic import BaseModel, field_validator, EmailStr
+from pydantic_core.core_schema import FieldValidationInfo
+
+
+class UserCreate(BaseModel):
+    username: str
+    password1: str
+    password2: str
+    email: EmailStr
+
+    @field_validator("username","password1", "password2", "email")
+    def not_empty(cls, v):
+        if not v or not v.strip():
+            raise ValueError("NOT_ALLOW_EMPTY_VALUE")
+        return v
+
+    @field_validator("password2")
+    def passwords_match(cls, v, info: FieldValidationInfo):
+        if "password1" in info.data and v != info.data["password1"]:
+            raise ValueError("PASSWORD_NOT_MATCH")
+        return v

main.py

@@ -2,6 +2,7 @@
 
 from domain.question import question_router
 from domain.answer import answer_router
+from domain.user import user_router
 
 
 app = FastAPI()
@@ -12,4 +13,5 @@ def health_check():
     return {"STATUS" : "WORKING_WELL..."}
 
 app.include_router(question_router.router)
-app.include_router(answer_router.router)
+app.include_router(answer_router.router)
+app.include_router(user_router.router)

models.py

@@ -20,4 +20,13 @@ class Answer(Base):
     content= Column(Text, nullable=False)
     create_date = Column(DateTime, nullable=False)
     question_id = Column(Integer, ForeignKey("question.id"))
-    question = relationship("Question", backref="answers")
+    question = relationship("Question", backref="answers")
+
+
+class User(Base):
+    __tablename__= "user"
+
+    id = Column(Integer, primary_key=True)
+    username = Column(String, nullable=False, unique=True)
+    password = Column(String, nullable=False)
+    email = Column(String, nullable=False, unique=True)