post에 공개용 id 추가

app/api.py

@@ -7,6 +7,7 @@
 from app.features.router import router as features_router
 from app.grad_2025.router import private_router as grad_2025_private_router
 from app.grad_2025.router import public_router as grad_2025_public_router
+from app.posts.public_router import router as posts_public_router
 from app.posts.router import router as posts_router
 from app.slack.router import router as slack_router
 from app.tags.router import router as tags_router
@@ -20,6 +21,7 @@
 public_router.include_router(
     grad_2025_public_router, prefix="/grad_2025", tags=["Grad 2025"]
 )
+public_router.include_router(posts_public_router, prefix="/posts", tags=["Posts"])
 
 private_router = create_router(
     prefix="/private",

app/posts/models.py

@@ -18,6 +18,7 @@
 
 from app.category.enums import Category
 from app.models import Base
+from app.utils.ulid import generate_ulid
 
 if TYPE_CHECKING:
     from app.users.models import User
@@ -51,6 +52,15 @@ class Post(Base):
         autoincrement=True,
     )
 
+    public_id: Mapped[str | None] = mapped_column(
+        String(26),
+        unique=True,
+        index=True,
+        nullable=True,
+        init=False,
+        default_factory=generate_ulid,
+    )
+
     author_id: Mapped[int] = mapped_column(ForeignKey("user.id"))
     author: Mapped["User"] = relationship(init=False, back_populates="posts")
 

app/posts/public_router.py

@@ -0,0 +1,39 @@
+import asyncio
+
+from fastapi import HTTPException
+
+from app.comments.repository import CommentRepository
+from app.core.router import create_router
+from app.like.repository import PostLikeRepository
+
+from .repository import PostRepository
+from .schemas import PostPublicRead
+
+router = create_router()
+
+
+@router.get("/{public_id}")
+async def read_post_public(
+    public_id: str,
+    post_repository: PostRepository,
+    post_like_repository: PostLikeRepository,
+    comment_repository: CommentRepository,
+) -> PostPublicRead:
+    """Public API: public_id로 게시물 조회 (인증 불필요)"""
+    post = await post_repository.find_by_public_id(public_id=public_id)
+
+    if not post:
+        raise HTTPException(status_code=404, detail="게시물을 찾을 수 없습니다.")
+
+    [like_count, comment_count, univ_major] = await asyncio.gather(
+        post_like_repository.count_by_id(post_id=post.id),
+        comment_repository.count_by_post_id(post_id=post.id),
+        post_repository.find_univ_major_by_post_id(post_id=post.id),
+    )
+
+    return PostPublicRead.from_post(
+        post,
+        like_count=like_count,
+        comment_count=comment_count,
+        univ_major=univ_major.name if univ_major else None,
+    )

app/posts/repository.py

@@ -47,6 +47,17 @@ async def find_by_id(self, post_id: int) -> Post | None:
         )
         return result.unique().scalar_one_or_none()
 
+    async def find_by_public_id(self, public_id: str) -> Post | None:
+        result = await self.session.execute(
+            select(Post)
+            .options(
+                joinedload(Post.author),
+                joinedload(Post.images),
+            )
+            .where(Post.public_id == public_id, Post.deleted_at.is_(None))
+        )
+        return result.unique().scalar_one_or_none()
+
     async def find_all(
         self,
         *,

app/posts/schemas.py

@@ -7,7 +7,7 @@
 from app.schemas import APISchema
 from app.storage.service import get_image_url
 from app.tags.schemas import Tag
-from app.users.schemas import UserRead
+from app.users.schemas import UserPublicRead, UserRead
 from app.utils.file_types import is_valid_image_type
 
 from .models import Post, PostImage
@@ -52,12 +52,14 @@ class PostBase(APISchema):
 
 class PostCompactRead(PostBase):
     id: int
+    public_id: str | None
     images: list[PostImageRead]
 
     @classmethod
     def from_post(cls, post: Post):
         return cls(
             id=post.id,
+            public_id=post.public_id,
             title=post.title,
             description=post.description,
             category=post.category,
@@ -71,6 +73,7 @@ def from_post(cls, post: Post):
 
 class PostRead(PostBase):
     id: int
+    public_id: str | None
     author: UserRead
 
     images: list[PostImageRead]
@@ -97,6 +100,7 @@ def from_post(
     ):
         return cls(
             id=post.id,
+            public_id=post.public_id,
             title=post.title,
             description=post.description,
             category=post.category,
@@ -115,6 +119,51 @@ def from_post(
         )
 
 
+class PostPublicRead(PostBase):
+    """Public API용 Post 응답 스키마 (인증 불필요)"""
+
+    id: int
+    public_id: str | None
+    author: UserPublicRead
+
+    images: list[PostImageRead]
+    like_count: int
+    comment_count: int
+
+    created_at: datetime
+    updated_at: datetime
+
+    univ_major: str | None = None
+
+    @classmethod
+    def from_post(
+        cls,
+        post: Post,
+        *,
+        like_count: int,
+        comment_count: int,
+        univ_major: str | None = None,
+    ):
+        return cls(
+            id=post.id,
+            public_id=post.public_id,
+            title=post.title,
+            description=post.description,
+            category=post.category,
+            author=UserPublicRead.from_user(post.author),
+            images=[
+                PostImageRead.from_post_image(image)
+                for image in sorted(post.images, key=lambda x: x.order)
+            ],
+            created_at=post.created_at,
+            updated_at=post.updated_at,
+            like_count=like_count,
+            comment_count=comment_count,
+            tags=post.tags,
+            univ_major=univ_major,
+        )
+
+
 class PostCreateUpdate(PostBase):
     images: list[PostImageCreate] = Field(min_length=1)
     univ_major: str | None = None

app/users/schemas.py

@@ -28,6 +28,26 @@
 ]
 
 
+class UserPublicRead(APISchema):
+    """Public API용 User 응답 스키마 (인증 불필요)"""
+
+    handle: Handle
+    nickname: str
+    profile_image: HttpUrl | None
+
+    @classmethod
+    def from_user(cls, user: User):
+        return cls(
+            handle=user.handle,
+            nickname=user.nickname,
+            profile_image=(
+                get_image_url(user.profile_image)
+                if user.profile_image is not None
+                else None
+            ),
+        )
+
+
 class UserRead(APISchema):
     handle: Handle
     nickname: str

app/utils/ulid.py

@@ -0,0 +1,6 @@
+from ulid import ULID
+
+
+def generate_ulid() -> str:
+    """새로운 ULID를 생성합니다."""
+    return str(ULID())

migrations/versions/2026-01-25_add_post_public_id.py

@@ -0,0 +1,32 @@
+"""empty message
+
+Revision ID: 40fea8c77b2e
+Revises: e8a40b987271
+Create Date: 2026-01-25 18:39:34.286713
+
+"""
+
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision: str = "40fea8c77b2e"
+down_revision: Union[str, None] = "e8a40b987271"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column("post", sa.Column("public_id", sa.String(length=26), nullable=True))
+    op.create_index(op.f("ix_post_public_id"), "post", ["public_id"], unique=True)
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(op.f("ix_post_public_id"), table_name="post")
+    op.drop_column("post", "public_id")
+    # ### end Alembic commands ###

pyproject.toml

@@ -17,6 +17,7 @@ dependencies = [
     "psycopg[binary,pool]>=3.2.6",
     "pydantic-settings>=2.8.1",
     "pyjwt[crypto]>=2.10.1",
+    "python-ulid>=3.1.0",
     "sqlalchemy[asyncio]>=2.0.39",
     "types-aioboto3[full]>=14.1.0",
 ]