Very early work on implementing websocket monitoring method.

lib/websocket/_url.py

@@ -0,0 +1,126 @@
+"""
+websocket - WebSocket client library for Python
+
+Copyright (C) 2010 Hiroki Ohtani(liris)
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor,
+    Boston, MA  02110-1335  USA
+
+"""
+
+from six.moves.urllib.parse import urlparse
+import os
+
+__all__ = ["parse_url", "get_proxy_info"]
+
+
+def parse_url(url):
+    """
+    parse url and the result is tuple of
+    (hostname, port, resource path and the flag of secure mode)
+
+    url: url string.
+    """
+    if ":" not in url:
+        raise ValueError("url is invalid")
+
+    scheme, url = url.split(":", 1)
+
+    parsed = urlparse(url, scheme="ws")
+    if parsed.hostname:
+        hostname = parsed.hostname
+    else:
+        raise ValueError("hostname is invalid")
+    port = 0
+    if parsed.port:
+        port = parsed.port
+
+    is_secure = False
+    if scheme == "ws":
+        if not port:
+            port = 80
+    elif scheme == "wss":
+        is_secure = True
+        if not port:
+            port = 443
+    else:
+        raise ValueError("scheme %s is invalid" % scheme)
+
+    if parsed.path:
+        resource = parsed.path
+    else:
+        resource = "/"
+
+    if parsed.query:
+        resource += "?" + parsed.query
+
+    return (hostname, port, resource, is_secure)
+
+
+DEFAULT_NO_PROXY_HOST = ["localhost", "127.0.0.1"]
+
+
+def _is_no_proxy_host(hostname, no_proxy):
+    if not no_proxy:
+        v = os.environ.get("no_proxy", "").replace(" ", "")
+        no_proxy = v.split(",")
+    if not no_proxy:
+        no_proxy = DEFAULT_NO_PROXY_HOST
+
+    return hostname in no_proxy
+
+
+def get_proxy_info(hostname, is_secure,
+            proxy_host=None, proxy_port=0, proxy_auth=None, no_proxy=None):
+    """
+    try to retrieve proxy host and port from environment
+    if not provided in options.
+    result is (proxy_host, proxy_port, proxy_auth).
+    proxy_auth is tuple of username and password
+     of proxy authentication information.
+
+    hostname: websocket server name.
+
+    is_secure:  is the connection secure? (wss)
+                looks for "https_proxy" in env
+                before falling back to "http_proxy"
+
+    options:    "http_proxy_host" - http proxy host name.
+                "http_proxy_port" - http proxy port.
+                "http_no_proxy"   - host names, which doesn't use proxy.
+                "http_proxy_auth" - http proxy auth infomation.
+                                    tuple of username and password.
+                                    defualt is None
+    """
+    if _is_no_proxy_host(hostname, no_proxy):
+        return None, 0, None
+
+    if proxy_host:
+        port = proxy_port
+        auth = proxy_auth
+        return proxy_host, port, auth
+
+    env_keys = ["http_proxy"]
+    if is_secure:
+        env_keys.insert(0, "https_proxy")
+
+    for key in env_keys:
+        value = os.environ.get(key, None)
+        if value:
+            proxy = urlparse(value)
+            auth = (proxy.username, proxy.password) if proxy.username else None
+            return proxy.hostname, proxy.port, auth
+
+    return None, 0, None