better error reporting

* use a template based on the Privoxy one * print a stack of the exceptions * link the documentation and issue tracker
2019-08-23 01:31:58 +02:00 · 2019-08-23 01:31:58 +02:00 · 5498e1de87
commit 5498e1de87
parent 05a6db87dd
4 changed files with 176 additions and 44 deletions
--- a/cert.py
+++ b/cert.py
@ -56,9 +56,9 @@ def get_cert(name, config):
    cafile: the CA file to create dummpy cert files
    certdir: the path where cert files are looked for or created
    '''
-    certfile = os.path.join(config.CERTDIR, name + '.crt')
+    certfile = os.path.join(config.certdir, name + '.crt')
    if not os.path.exists(certfile):
-        dummy_cert(config.CA, certfile, name)
+        dummy_cert(config.ca, certfile, name)
    return certfile


--- a/data/error.html
+++ b/data/error.html
@ -0,0 +1,107 @@
+<!doctype html>
+<html>
+  <head>
+    <meta encoding="utf-8">
+    <style>
+        * { box-sizing: border-box; }
+
+        body {
+          font-family: Helvetica, Arial, sans-serif;
+          color: black;
+          background: white;
+          margin: 1.2em;
+        }
+
+        article, footer {
+          border: 1px solid black;
+          width: 100%;
+          margin-top: 0.6em;
+          padding: 1em;
+        }
+
+        header {
+          height: 7em;
+          display: flex;
+          margin: 0;
+        }
+
+        header div {
+          display: flex;
+          align-items: center;
+          border: 1px solid black;
+          margin: 0 0.3rem;
+          padding: 1rem;
+        }
+
+        header div:first-child { margin-left: 0; }
+        header div:last-child { margin-right: 0; }
+
+        #status {
+          background: red;
+          color: white;
+          font-size: 300%;
+          font-weight: bolder;
+        }
+
+        #title {
+          background: #ddd;
+          width: 100%;
+        }
+
+        #message { background: #fdd; }
+        article  { background: #eee; }
+        footer   { background: #ccf; }
+
+        h1, h2, h3 { margin: 0; }
+        h1 { font-size: 140% }
+        h2 { font-size: 120% }
+        h3 { font-size: 110% }
+
+        a { text-decoration: none; }
+        a:link    { color: #00d; }
+        a:visited { color: #309; }
+        a:active  { color: #33f; }
+    </style>
+    <title>$server: Error $code</title>
+  </head>
+
+  <body>
+    <header>
+      <div id="status">$code</div>
+
+      <div id="title">
+        <h1>
+          This is <a href="https://maxwell.ydns.eu/git/rnhmjoj/privoxy-tls">$server</a>
+          on $hostname ($address), port $port
+        </h1>
+      </div>
+    </header>
+
+    <article id="message">
+      <h2>$message:</h2>
+      <p>
+        Your request for <b><a href="$url">$url</a></b> could not be fulfilled
+        because an error occured.
+      </p>
+    </article>
+
+    <article>
+      <h2>More information:</h2>
+      $explain
+      <p>Error generated on $now.</p>
+    </article>
+
+    <footer>
+      <h2>Support:</h2> 
+      <p>
+        Please have a look at the
+        <a href="https://maxwell.ydns.eu/git/rnhmjoj/privoxy-tls">documentation</a>
+        to learn how to configure Privoxy TLS correctly.
+      </p>
+      <p>
+        If you are encountering a problem consider opening an
+        <a href="https://maxwell.ydns.eu/git/rnhmjoj/privoxy-tls/issues">issue</a>.
+      </p>
+    </footer>
+  </body>
+</html>
--- a/main.py
+++ b/main.py
@ -29,16 +29,19 @@ _name = 'privoxy-tls'

 class LoadConfig:
    def __init__(self, configfile):
-        self.config = configparser.ConfigParser(allow_no_value=True,
-                                                inline_comment_prefixes=('#',))
+        self.config = configparser.ConfigParser(
+            allow_no_value=True, delimiters=('=',),
+            inline_comment_prefixes=('#',))
        self.config.read(configfile)
-        self.PROXADDR     = self.config['General'].get('ProxAddr')
-        self.FRONTPORT    = int(self.config['General'].get('FrontPort'))
-        self.REARPORT     = int(self.config['General'].get('RearPort'))
-        self.GeneralPROXY = self.config['General'].get('DefaultProxy')
-        self.LOGLEVEL     = self.config['General'].get('LogLevel')
-        self.CA           = self.config['General'].get('CACert')
-        self.CERTDIR      = self.config['General'].get('CertDir')
+        self.proxy_name = self.config['General'].get('ProxAddr')
+        self.front_name = self.config['General'].get('FrontAddr', 'localhost')
+        self.rear_name  = self.config['General'].get('RearAddr', 'localhost')
+        self.front_port = int(self.config['General'].get('FrontPort'))
+        self.rear_port  = int(self.config['General'].get('RearPort'))
+        self.proxy      = self.config['General'].get('DefaultProxy')
+        self.loglevel   = self.config['General'].get('LogLevel')
+        self.ca         = self.config['General'].get('CACert')
+        self.certdir    = self.config['General'].get('CertDir')

     
 class ConnectionPools:
@ -307,7 +310,7 @@ class FrontRequestHandler(ProxyRequestHandler):
            logger.warning(f'{self.reqNum:03d} [F] {e} on '
                           f'"{self.command} {url}"')
        except (urllib3.exceptions.HTTPError,) as e:
-            self.sendout_error(url, 502, message="HTTPError", explain=e)
+            self.sendout_error(url, 502, message="HTTP Error", explain=e)
            logger.warning(f'{self.reqNum:03d} [F] {e} on '
                           f'"{self.command} {url}"')
        finally:
@ -323,7 +326,7 @@ class RearRequestHandler(ProxyRequestHandler):
    Supposed to be the parent proxy for Privoxy for tagged requests
    Convert http request to https
    """
-    server_version = f'{_name} front/{__version__}'
+    server_version = f'{_name} rear/{__version__}'

    def do_METHOD(self):
        "Convert http request to https"
@ -409,7 +412,7 @@ class RearRequestHandler(ProxyRequestHandler):
            logger.warning(f'{self.reqNum:03d} [R]{prefix} '
                           f'"{self.command} {url}" {e}')
        except (urllib3.exceptions.HTTPError,) as e:
-            self.sendout_error(url, 502, message="HTTPError", explain=e)
+            self.sendout_error(url, 502, message="HTTP Error", explain=e)
            logger.warning(f'{self.reqNum:03d} [R]{prefix} '
                           f'"{self.command} {url}" {e}')

@ -423,16 +426,18 @@ class RearRequestHandler(ProxyRequestHandler):

 def main():
    urllib3.disable_warnings()
-    logger.setLevel(getattr(logging, config.LOGLEVEL, logging.INFO))
+    logger.setLevel(getattr(logging, config.loglevel, logging.INFO))
    handler = logging.StreamHandler()
    formatter = logging.Formatter('%(asctime)s %(message)s', datefmt='[%H:%M]')
    handler.setFormatter(formatter)
    logger.addHandler(handler)

-    frontserver = FrontServer(('', config.FRONTPORT), FrontRequestHandler)
-    rearserver = RearServer(('', config.REARPORT), RearRequestHandler)
-    frontserver.config = config
-    for worker in (frontserver.serve_forever, rearserver.serve_forever,
+    frontserver = FrontServer((config.front_name, config.front_port),
+                              FrontRequestHandler)
+    rearserver = RearServer((config.rear_name, config.rear_port),
+                            RearRequestHandler)
+    for worker in (frontserver.serve_forever,
+                   rearserver.serve_forever,
                   pools.reloadConfig):
        thread = threading.Thread(target=worker)
        thread.daemon = True
@ -440,10 +445,10 @@ def main():

    print('=' * 40)
    print(f'{_name} {__version__} (urllib3/{urllib3.__version__})')
-    print(f'Front   : localhost:{config.FRONTPORT}')
-    print(f'Privoxy : {config.PROXADDR}')
-    print(f'Rear    : localhost:{config.REARPORT}')
-    print(f'Parent  : {config.GeneralPROXY}')
+    print(f'Front   : {config.front_name}:{config.front_port}')
+    print(f'Privoxy : {config.proxy_name}')
+    print(f'Rear    : {config.rear_name}:{config.rear_port}')
+    print(f'Proxy   : {config.proxy}')
    print('=' * 40)
    while True:
        time.sleep(1)
@ -461,7 +466,7 @@ if __name__ == '__main__':
    logger = logging.getLogger(__name__)
    config = LoadConfig(CONFIG)
    proxpool = urllib3.ProxyManager(
-        config.PROXADDR, num_pools=10, maxsize=8,
+        config.proxy_name, num_pools=10, maxsize=8,
        timeout=urllib3.util.timeout.Timeout(
            connect=90.0, read=310.0))
    pools = ConnectionPools(CONFIG)
--- a/proxy.py
+++ b/proxy.py
@ -12,6 +12,8 @@ import cgi
 import socket
 import select
 import ssl
+import string
+import pathlib

 from http.server import HTTPServer, BaseHTTPRequestHandler
 from socketserver import ThreadingMixIn
@ -20,23 +22,36 @@ from cert import get_cert
 _name = 'proxy'
 logger = logging.getLogger('__main__')

-message_format = '''\
-<!doctype html>
-<html>
-  <head>
-    <meta http-equiv="Content-Type" content="text/html;charset=utf-8">
-    <title>Proxy Error: {code}</title>
-  </head>
-  <body>
-    <h1>{code}: {message}</h1>
-    <p>The following error occurred while
-       trying to access <strong>{url}</strong>
-    </p>
-    <p><strong>{explain}</strong></p>
-    <hr>Generated on {now} by {server}.
-  </body>
-</html>
-'''
+data = pathlib.Path(__file__).parent / 'data'
+error_template = string.Template(open(data / 'error.html').read())
+
+
+def walk_traceback(e, n=0):
+    '''
+    Produce an HTML formatted stack trace
+    given an exception.
+    '''
+    partial = []
+    ul = lambda xs: ('<ul><li>'
+                     + '</li>\n<li>'.join(xs)
+                     + '</li></ul>')
+
+    for i, arg in enumerate(e.args):
+        name = (('<strong>'
+            + type(e).__name__
+            + '</strong>') if i == 0 else '')
+        if isinstance(arg, str):
+            partial.append(
+                name + ' -  '
+                + arg.replace('<', '&lt;').replace('>', '&gt;'))
+        else:
+            partial.append(name)
+
+        if isinstance(arg, Exception):
+            partial.append(walk_traceback(arg, n+1))
+    if n == 0:
+        partial.append(walk_traceback(e.reason, n+1))
+    return ul(partial)


 def read_write(socket1, socket2, max_idling=10):
@ -157,10 +172,15 @@ class ProxyRequestHandler(BaseHTTPRequestHandler):
            message = shortmsg
        if explain is None:
            explain = longmsg
-        content = message_format.format(
+
+        content = error_template.substitute(
            code=code, message=message,
-            explain=explain, url=url,
-            now=datetime.today(),
+            explain=walk_traceback(explain),
+            url=url,
+            hostname=self.server.server_name,
+            address=self.server.server_address[0],
+            port=self.server.server_port,
+            now=datetime.today().isoformat(sep=' ', timespec='seconds'),
            server=self.server_version)
        body = content.encode('UTF-8', 'replace')
        self.send_response_only(code, message)