fix: code quality

main.py

@@ -1,24 +1,38 @@
+#!/usr/bin/env python3
+"""
+Serve cloud init files
+"""
+
+import configparser
 import os
+import socket
 import sys
+from ipaddress import AddressValueError, IPv4Address, IPv6Address
 
+import yaml
 import cherrypy
 from cherrypy.lib.static import serve_file
-import yaml
-import socket
 
-import configparser
 
 PATH = os.path.dirname(os.path.abspath(__file__))
 
-config = configparser.ConfigParser()
-config.read(os.path.join(PATH, "config.ini"))
+CONFIG = configparser.ConfigParser()
+CONFIG.read(os.path.join(PATH, "config.ini"))
+
+USER_DATA_FILENAME = CONFIG["app"].get("user_data", "user-data")
+META_DATA_FILENAME = CONFIG["app"].get("meta_data", "meta-data")
+REDIRECT_FILENAME = CONFIG["app"].get("redirect", "redirect")
+
 
-user_data_filename = config["app"].get("user_data", "user-data")
-meta_data_filename = config["app"].get("meta_data", "meta-data")
-redirect_filename = config["app"].get("redirect", "redirect")
+class CloudInitApp:
+    """
+    Serve cloud init files
+    """
 
+    def __init__(self):
+        self.remoteip = None
+        self.hostinfo = ('localhost', )
 
-class MainApp:
     def _can_ip_be_proxy(self):
         self.remoteip = cherrypy.request.remote.ip
         try:
@@ -46,17 +60,17 @@ class MainApp:
         try:
             self.hostinfo = socket.gethostbyaddr(self.remoteip)
         except socket.herror:
-            self.hostinfo = ('localhost', )
+            pass
 
     def _redirect_if_needed(self):
         filepath = os.path.join(PATH, "data", self.hostinfo[0],
-                                "redirect")
+                                REDIRECT_FILENAME)
         if os.path.exists(filepath):
             try:
-                with open(filepath) as f:
-                    content = f.read().splitlines()
+                with open(filepath) as redirect:
+                    content = redirect.read().splitlines()
                 raise cherrypy.HTTPRedirect(content[0], 301)
-            except BaseException:
+            except IOError:
                 return False
         return False
 
@@ -68,10 +82,10 @@ class MainApp:
         self._init_ip()
         self._redirect_if_needed()
         filepath = os.path.join(PATH, "data", self.hostinfo[0],
-                                user_data_filename)
+                                USER_DATA_FILENAME)
         if not os.path.exists(filepath):
-            filepath = os.path.join(PATH, "data", user_data_filename)
-        return serve_file(filepath, "application/x-download", "attachment")
+            filepath = os.path.join(PATH, "data", USER_DATA_FILENAME)
+        return serve_file(filepath, "text/yaml", "attachment")
 
     @cherrypy.expose
     def meta_data(self):
@@ -82,17 +96,21 @@ class MainApp:
         self._redirect_if_needed()
         hostname = self.hostinfo[0]
         data = {
-                "instance-id": hostname.split(".")[0],
-                "local-hostname": hostname
+            "instance-id": hostname.split(".")[0],
+            "local-hostname": hostname
         }
 
-        filepath = os.path.join(PATH, "data", hostname, meta_data_filename)
+        filepath = os.path.join(PATH, "data", hostname, META_DATA_FILENAME)
         if os.path.exists(filepath):
             with open(filepath, "r") as metadata:
                 for line in metadata.readlines():
                     linesplit = list(map(lambda k: k.strip(), line.split(":")))
                     data[linesplit[0]] = linesplit[1]
 
+        cherrypy.response.headers['Content-Type'] = \
+            'text/yaml'
+        cherrypy.response.headers['Content-Disposition'] = \
+            'attachment; filename="user-data"'
         return yaml.dump(data)
 
     @cherrypy.expose
@@ -114,15 +132,17 @@ class MainApp:
         if not os.path.exists(folder):
             os.makedirs(folder)
 
-        with open(os.path.join(folder, meta_data_filename), "w") as f:
-            f.write(data)
+        with open(os.path.join(folder, META_DATA_FILENAME), "w") as fin:
+            fin.write(data)
 
 
-ROOT = MainApp()
+ROOT = CloudInitApp()
 
 if __name__ == "__main__":
-    cherrypy.server.socket_host = config["server"].get("server_host", "127.0.0.1")
-    cherrypy.server.socket_port = config["server"].getint("server_port", 8081)
+    cherrypy.server.socket_host = \
+        CONFIG["server"].get("server_host", "127.0.0.1")
+    cherrypy.server.socket_port = \
+        CONFIG["server"].getint("server_port", 8081)
     ENGINE = cherrypy.engine
 
     cherrypy.tree.mount(ROOT)