add(backend): cache-control header

Co-authored-by: Ada <ada@gnous.eu>
Co-committed-by: Ada <ada@gnous.eu>

README.md

@@ -0,0 +1,11 @@
+# A code share paste
+
+## Run
+Require redis and python, install python requirements with `pip install -r requirements.txt`. Run with `flask --app paste run` (add `--debug` for devlopement)
+You can configure with multiple environnement variables.
+- PASTE_REDIS_HOST: redis host (default localhost)
+- PASTE_REDIS_PORT: redis port (default 6379)
+- PASTE_REDIS_USER: redis username (default none)
+- PASTE_REDIS_PASSWORD: redis password (default none)
+- PASTE_URL_LENGTH: length for url used by paste
+- PASTE_SECRET_KEY: secret key for flask, don't use the default value (generate a safe value with `openssl rand -hex 16`).

paste/config.py

@@ -2,7 +2,7 @@
 from os import getenv
 
 REDIS_HOST = getenv("PASTE_REDIS_HOST") or "localhost"
-REDIS_PORT = getenv("PASTE_REDIS_HOST") or "6379"
+REDIS_PORT = getenv("PASTE_REDIS_PORT") or "6379"
 REDIS_USER = getenv("PASTE_REDIS_USER") or None
 REDIS_PASSWORD = getenv("PASTE_REDIS_PASSWORD") or None
 URL_LENGTH = getenv("PASTE_URL_LENGTH") or 4

paste/db.py

@@ -31,7 +31,7 @@ def insert_content_db(url_id: str, expiration: int, content: str, secret: str) -
 
     :param secret: Secret key for delete url
     :param url_id: key for access to content.
-    :param expiration: Content expiration in second.
+    :param expiration: Content expiration in second. Set 0 if no expiration.
     :param content: Paste content
     :return: None
     """
@@ -40,6 +40,7 @@ def insert_content_db(url_id: str, expiration: int, content: str, secret: str) -
         data = {"content": content, "secret": secret}
         for key, key_content in data.items():
             db.hset(url_id, key, key_content)
+        if expiration != 0:
             db.expire(url_id, expiration)
     else:
         logging.error(f"Key : {url_id} already exist") # noqa: G004

paste/home.py

@@ -12,7 +12,7 @@ from flask import (
 from werkzeug import Response
 
 from paste.db import check_content_exist, connect_redis, insert_content_db
-from paste.utils import generate_id, generate_secret
+from paste.utils import generate_id, generate_secret, get_expiration_time
 
 home = Blueprint("home", __name__, url_prefix="/")
 
@@ -49,11 +49,12 @@ def create() -> Response:
     """
     content = request.form.get("content")
     time = request.form.get("time")
-    time = 86400 if time == "" else int(time)
+    time = 0 if time == "" else int(time)
 
     flash_data = create_paste(content, time)
     flash(flash_data["url_id"], category="create")
     flash(flash_data["secret"], category="create")
+
     return redirect(url_for("home.homepage"))
 
 
@@ -74,7 +75,7 @@ def delete_paste(path: str) -> Response:
 
 
 @home.route("/<path:path>")
-def get_content(path: str) -> str:
+def get_content(path: str) -> Response | str:
     """
     Return paste for asked url.
     :param path: Requested path.
@@ -84,6 +85,13 @@ def get_content(path: str) -> str:
     data = db.hgetall(path)
     if check_content_exist(path):
         flash(data["content"])
-        return render_template("content.html.j2")
+        cache_time = get_expiration_time(path)
+        current_response = Response(render_template("content.html.j2"))
+        if cache_time == -1:
+            current_response.headers["Cache-Control"] = "public"
+
+        else:
+            current_response.headers["Cache-Control"] = f"public, {cache_time}"
+        return current_response
 
     return abort(404)

paste/utils.py

@@ -5,6 +5,7 @@ import secrets
 import string
 
 from paste import config
+from paste.db import connect_redis
 
 
 def generate_id() -> str:
@@ -24,3 +25,13 @@ def generate_secret() -> str:
     :return: The secret.
     """
     return secrets.token_hex()
+
+
+def get_expiration_time(key: str) -> int:
+    """
+    Get key expiration time
+    :param key: Key to check
+    :return: Expiration time in second.
+    """
+    db = connect_redis()
+    return db.ttl(key)

pyproject.toml

@@ -59,7 +59,6 @@ exclude = [
     "instances",
     "schema.sql"
 ]
-format = "grouped"
 
 [tool.isort]
 profile = "black"

requirements-dev.txt

@@ -1,3 +1,2 @@
-flask==2.3.3
-redis==5.0.0
+-r requirements.txt
 ruff==0.0.291