Bottle: Login/Logout/File Upload/Download Demo

bottle_demo.py

"""Bottle framework demonstration

Below items are demonstrated here:
==================================
- Login/Logout using cookies
- File upload/download
- Hooks
- Plugins
- 404 error handling
- Jinja2 template usage
- HTTP Caching

:author: Suresh K L <suresh1591@gmail.com>
"""
import os
import time
from functools import wraps

from bottle import request, response, template, abort, run, redirect
from bottle import static_file
from bottle import Bottle
from bottle import jinja2_template

app = Bottle()
secret = os.urandom(10)
downloads = os.path.join(os.path.dirname(__file__), 'downloads')


##############################################################################
# HOOKS
##############################################################################

def setup():
    response.add_header('X-Before-Request', 'setup')


def teardown():
    response.add_header('X-After-Request', 'teardown')

##############################################################################
# PLUGINS
##############################################################################

def stopwatch(callback):
    @wraps(callback)
    def wrapper(*args, **kwargs):
        start_time = time.time()
        result = callback(*args, **kwargs)
        end_time = str(time.time() - start_time)
        response.add_header('X-EXEC-TIME', end_time)
        return result
    return wrapper

class DownloadFilePlugin:
    """Class based plugin demo"""
    name = 'download_file_plugin'
    api = 2

    def __init__(self):
        print('DemoPlugin init called')

    def apply(self, callback, route):
        print('apply called')
        def wrapper(*args, **kwargs):
            rv = callback(*args, **kwargs)
            return rv
        return wrapper

##############################################################################
# TEMPLATES
##############################################################################
welcome_page = '''
<h1>Welcome {{ user }}</h1>
'''

upload_form = '''
<form action="/upload" method="POST" enctype="multipart/form-data">
    <input type="file" name="file">
    <input type="submit" value="Upload">
</form>
'''

login_form = '''
<form action="/login" method="POST">
    Username: <input type="text" name="username"><br>
    Password: <input type="password" name="password"><br>
              <input type="submit" value="Login">
</form>
'''

logout_form = '''
<form action="/logout" method="GET">
    <input type="submit" value="Logout">
</form>
'''

page_not_found = '''
<h1>Requested page not found, please check the URL</h1>
'''

home_page = welcome_page +  upload_form + logout_form

##############################################################################
# VIEWS
##############################################################################
@app.error(404)
def error404(error):
    return template(page_not_found)


@app.get('/')
def home():
    loggedin = request.get_cookie('loggedin', secret=secret)
    if loggedin:
        username = request.get_cookie('username')
        return template(home_page, user=username)
    else:
        return template(login_form)


@app.post('/login')
def login():
    username = request.params.get('username')
    password = request.params.get('password')
    if username == 'admin' and password == 'admin':
        response.set_cookie('loggedin', True, secret=secret)
        response.set_cookie('username', username)
        return template(home_page, user=username)
    else:
        abort(401, 'Unauthorized')


@app.get('/logout')
def logout():
    loggedin = request.get_cookie('loggedin', secret=secret)
    if loggedin:
        response.set_cookie('loggedin', False, secret=secret)
    redirect('/')

@app.get('/files')
def list_files():
    file_type = request.query.type or '*'
    import glob
    files = glob.glob1(os.path.dirname(__file__), file_type)
    return [f'<ol>{f}</ol>' for f in files]

@app.post('/upload')
def upload_file():
    """Upload file to server

    Use this way to upload via python requests requests module:
    ===========================================================

    >>> import os
    >>> import requests
    >>>
    >>> url = 'http://localhost:8080/upload'
    >>> file = __file__
    >>> size = os.path.getsize(file)
    >>> headers = {'X-File-Size': str(size)}  # Custom header
    >>> files = {'file': open(file, 'rb')}  # Syntax 1
    >>> # files = {'file': ('new_file.py', open(file, 'rb'), 'text/html')}  # Syntax 2
    >>> resp = requests.post(url, files=files, headers=headers)
    >>> print(resp.status_code)
    >>> print(resp.text)
    """
    os.makedirs(downloads, exist_ok=True)
    uploaded_file = request.files.get('file')
    if uploaded_file:
        file_path = os.path.join(downloads, uploaded_file.filename)
        # Check if file with same name and size exists
        if os.path.isfile(file_path):
            source_size = int(request.get_header('X-File-Size', 0))
            dest_size = os.path.getsize(file_path)
            if source_size == dest_size:
                return 'Same file exists'

        uploaded_file.save(downloads, overwrite=True)
        return jinja2_template('Uploaded {{ filename }} to {{ downloads }}',
                               filename=uploaded_file.filename,
                               downloads=os.path.abspath(downloads))
    abort(500, 'Upload failed')

@app.get('/download/<filename:path>', apply=[DownloadFilePlugin()])  # Explicitly apply download_file_plugin
def download_file(filename):
    """Download file from server

    Use this way to download file using python requests module:
    ===========================================================

    >>> import requests
    >>>
    >>> filename = 'image.JPG'
    >>> url = f'http://localhost:8080/download/{filename}'
    >>> with requests.get(url, stream=True) as resp:
    >>>     if resp.status_code == 200:
    >>>         with open(filename, 'wb') as f:
    >>>             for line in resp.iter_content():
    >>>                 f.write(line)
    >>>     else:
    >>>         resp.raise_for_status()
    """
    return static_file(filename, root=downloads, download=True)

@app.get('/ip', skip=[stopwatch])  # stopwatch Plugin is skipped for this route
def client_ip():
    ip = request.environ.get('REMOTE_ADDR')
    return f'Your IP is : {ip}'

@app.get('/secured')
def secured():
    print(request.auth)
    if request.auth:
        username, password = request.auth
        print(username, password)

@app.get('/image/fromcache/<filename:path>')
def show_image_from_cache(filename):
    response = static_file(filename, root=downloads)
    response.set_header('Cache-Control', 'max-age=10')
    time.sleep(3)
    return response

@app.get('/image/notfromcache/<filename:path>')
def show_image(filename):
    time.sleep(3)
    response = static_file(filename, root=downloads)
    response.set_header('Cache-Control', 'no-store')
    return response
##############################################################################

if __name__ == '__main__':
    app.install(stopwatch)  # Install plugin to all routes
    app.add_hook('before_request', setup)
    app.add_hook('after_request', teardown)
    run(app, debug=True, reloader=True)