How to serve static files in Flask

Question

So this is embarrassing. I've got an application that I threw together in Flask and for now it is just serving up a single static HTML page with some links to CSS and JS. And I can't find where in the documentation Flask describes returning static files. Yes, I could use render_template but I know the data is not templatized. I'd have thought send_file or url_for was the right thing, but I could not get those to work. In the meantime, I am opening the files, reading content, and rigging up a Response with appropriate mimetype:

import os.path  from flask import Flask, Response   app = Flask(__name__) app.config.from_object(__name__)   def root_dir():  # pragma: no cover     return os.path.abspath(os.path.dirname(__file__))   def get_file(filename):  # pragma: no cover     try:         src = os.path.join(root_dir(), filename)         # Figure out how flask returns static files         # Tried:         # - render_template         # - send_file         # This should not be so non-obvious         return open(src).read()     except IOError as exc:         return str(exc)   @app.route('/', methods=['GET']) def metrics():  # pragma: no cover     content = get_file('jenkins_analytics.html')     return Response(content, mimetype="text/html")   @app.route('/', defaults={'path': ''}) @app.route('/<path:path>') def get_resource(path):  # pragma: no cover     mimetypes = {         ".css": "text/css",         ".html": "text/html",         ".js": "application/javascript",     }     complete_path = os.path.join(root_dir(), path)     ext = os.path.splitext(path)[1]     mimetype = mimetypes.get(ext, "text/html")     content = get_file(complete_path)     return Response(content, mimetype=mimetype)   if __name__ == '__main__':  # pragma: no cover     app.run(port=80) 

Someone want to give a code sample or url for this? I know this is going to be dead simple.

Answer 1

The preferred method is to use NGINX or another web server to serve static files; they'll be able to do it more efficiently than Flask.

However, you can use send_from_directory to send files from a directory, which can be pretty convenient in some situations:

from flask import Flask, request, send_from_directory  # set the project root directory as the static folder, you can set others. app = Flask(__name__, static_url_path='')  @app.route('/js/<path:path>') def send_js(path):     return send_from_directory('js', path)  if __name__ == "__main__":     app.run() 

Alternatively, you could use app.send_file or app.send_static_file, but this is highly discouraged as it can lead to security risks with user-supplied paths; send_from_directory was designed to control those risks.