Posts CRUD and Ownership

Goal

This snapshot advances Rivermouth Dispatch by teaching you to create, edit, and delete posts with owner authorization.

Every numbered folder is a complete app. Run this stage independently, then compare it with the previous folder.

Prerequisites

Use Python 3.11+, a terminal, and Docker for Postgres stages. You should recognize functions, modules, and HTTP verbs.

Port 8001 must be free. Copy .env.example before starting database stages.

• Python 3 and pip/venv
• A code editor and terminal
• Docker from part 4 onward

Concepts

Authentication identifies a user; authorization compares that identity with post.author_id before mutations.

Keep request handling thin: routes accept input, services/models enforce rules, and Jinja templates escape output by default.

Walkthrough

Create posts with the session user id and return 403 when another account attempts edit or delete.

Read the example, then open the matching snapshot. The repository includes the surrounding setup and error handling.

if not user or user.id != post.author_id:
    raise HTTPException(403)

Run and verify

Enter 09-Posts-CRUD-And-Ownership, create a virtualenv, install requirements, copy .env.example when present, and start Uvicorn on port 8001.

Open http://127.0.0.1:8001. Watch the terminal for validation and database errors.

docker compose up -d
git clone https://github.com/michaeldunga1/fcc-fastapi-blog.git
cd fcc-fastapi-blog/09-Posts-CRUD-And-Ownership
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
cp .env.example .env
uvicorn main:app --reload --port 8001

Troubleshooting

Forgetting the ownership check is a security bug even if the UI hides edit links.

Import errors usually mean the virtualenv is inactive or you installed packages in another snapshot. For Postgres failures, confirm Docker and the rivermouth_NN database name.

• Read the first error first
• Restart after environment changes
• Never commit .env or .venv

Try this

Log in as Ada and confirm Grace's post returns 403 on delete.

Test a happy path and one invalid or unauthorized request.

• Make one small change
• Test it in the browser
• Compare with the next snapshot only after it works