def canonize(request, website):
"""Enforce a certain scheme and hostname.
This is a Pando state chain function to ensure that requests are served on a
certain root URL, even if multiple domains point to the application.
"""
is_callback = request.path.raw.startswith('/callbacks/')
is_healthcheck = request.headers.get(b'User-Agent',
b'').startswith(b'ELB-HealthChecker')
if is_callback or is_healthcheck:
# Don't redirect callbacks
if request.path.raw[-1] == '/' or is_healthcheck:
l = request.line
scheme, netloc, path, query, fragment = urlsplit(l.uri)
assert path[-1] == '/' # sanity check
path = '/callbacks/health.txt' if is_healthcheck else path[:-1]
new_uri = urlunsplit((scheme, netloc, path, query, fragment))
request.line = Line(l.method.raw, new_uri, l.version.raw)
return
scheme = request.headers.get(b'X-Forwarded-Proto', b'http')
try:
request.hostname = host = request.headers[b'Host'].decode('idna')
except UnicodeDecodeError:
request.hostname = host = ''
canonical_host = website.canonical_host
canonical_scheme = website.canonical_scheme
bad_scheme = scheme.decode('ascii', 'replace') != canonical_scheme
bad_host = False
if canonical_host:
if host == canonical_host:
pass
elif host.endswith('.' + canonical_host):
subdomain = host[:-len(canonical_host) - 1]
if subdomain in website.locales:
accept_langs = request.headers.get(b'Accept-Language', b'')
accept_langs = subdomain.encode('idna') + b',' + accept_langs
request.headers[b'Accept-Language'] = accept_langs
else:
bad_host = True
else:
bad_host = True
if bad_scheme or bad_host:
url = '%s://%s' % (canonical_scheme,
canonical_host if bad_host else host)
if request.line.method in ('GET', 'HEAD', 'OPTIONS', 'TRACE'):
# Redirect to a particular path for idempotent methods.
url += request.line.uri.path.raw
if request.line.uri.querystring:
url += '?' + request.line.uri.querystring.raw
else:
# For non-idempotent methods, redirect to homepage.
url += '/'
response = Response()
response.headers[b'Cache-Control'] = b'public, max-age=86400'
response.redirect(url)
def test_line_has_version():
line = Line(b"GET", b"/", b"HTTP/0.9")
assert line.version == b"HTTP/0.9"
def test_line_has_method():
line = Line(b"GET", b"/", b"HTTP/0.9")
assert line.method == b"GET"
def test_line_has_uri():
line = Line(b"GET", b"/", b"HTTP/0.9")
assert line.uri == b"/"
def test_line_works():
line = Line(b"GET", b"/", b"HTTP/0.9")
assert line == b"GET / HTTP/0.9"