Add v2 API with UUID support

- refactoring
- code quality

main.py

@@ -8,6 +8,7 @@ import os
 import socket
 import sys
 from ipaddress import AddressValueError, IPv4Address, IPv6Address
+from os import access, R_OK
 
 import cherrypy
 # from cherrypy.lib.static import serve_file
@@ -24,17 +25,27 @@ META_DATA_FILENAME = CONFIG["app"].get("meta_data", "meta-data")
 REDIRECT_FILENAME = CONFIG["app"].get("redirect", "redirect")
 
 
-class CloudInitApp:
+class CloudInitRequest:
     """
-    Serve cloud init files
+    Request data for persistence across methods
     """
-
-    def __init__(self):
+    def __init__(self, request, uuid=None):
         self.remoteip = None
         self.hostinfo = ('localhost', )
+        self.request = request
+        self.uuid = uuid
+        self.meta_data = None
+        self.meta_data_loaded = False
+        self.user_data = None
+        self._init_ip()
+        self._generate_default_meta_data()
 
     def _can_ip_be_proxy(self):
-        self.remoteip = cherrypy.request.remote.ip
+        """
+        Assuming the connection is through a proxy, is this proxy permitted?
+        Can't proxy from a publicly reachable IP.
+        """
+        self.remoteip = self.request.remote.ip
         try:
             ipobj = IPv4Address(self.remoteip)
         except AddressValueError:
@@ -50,9 +61,9 @@ class CloudInitApp:
         """
         if self._can_ip_be_proxy():
             try:
-                self.remoteip = cherrypy.request.headers.get(
+                self.remoteip = self.request.headers.get(
                     'X-Real-Ip',
-                    cherrypy.request.remote.ip
+                    self.request.remote.ip
                 )
             except KeyError:
                 pass
@@ -67,115 +78,211 @@ class CloudInitApp:
         except socket.gaierror:
             self.hostinfo = (self.remoteip, )
 
-    def _redirect_if_needed(self):
-        filepath = os.path.join(PATH, "data", self.hostinfo[0],
-                                REDIRECT_FILENAME)
-        if os.path.exists(filepath):
-            try:
-                with open(filepath) as redirect:
-                    content = redirect.read().splitlines()
-                raise cherrypy.HTTPRedirect(content[0], 301)
-            except IOError:
-                return False
-        return False
-
-    def _generate_metadata(self):
-        self._init_ip()
+    def _generate_default_meta_data(self):
+        """
+        Build default meta-data based on the requesting IP
+        """
         hostname = self.hostinfo[0]
-        base = cherrypy.request.base
-        data = {
+        base = self.request.base
+        self.meta_data = {
             "instance-id": hostname.split(".")[0],
             "local-hostname": hostname,
             "baseurl": base
         }
-        return data
+
+    def _update_meta_data_from_file(self, filename):
+        """
+        Load meta-data from a file
+        """
+        with open(filename, "r") as metadata:
+            self.meta_data.update(yaml.safe_load(metadata))
+
+    def _get_filename(self, filetype):
+        """
+        Get the best available filename for a given type
+        """
+        check_dirs = ['localhost', ]
+        if self.uuid:
+            check_dirs.insert(0, self.uuid)
+        if self.meta_data['local-hostname'] != 'localhost':
+            check_dirs.insert(0, self.meta_data['local-hostname'])
+        for subdir in check_dirs:
+            filepath = os.path.join(PATH, "data",
+                                    subdir,
+                                    filetype)
+            if not os.path.isfile(filepath) \
+               or not access(filepath, R_OK):
+                continue
+            return filepath
+        return None
+
+    def get_meta_data(self):
+        """
+        Return the appropriate meta-data for this request
+        """
+        if self.meta_data_loaded:
+            return self.meta_data
+        self._generate_default_meta_data()
+        filename = self._get_filename(META_DATA_FILENAME)
+        if filename:
+            self._update_meta_data_from_file(
+                    filename
+                )
+        self.meta_data_loaded = True
+        return self.meta_data
+
+    def save_meta_data(self, data):
+        """
+        Save metadata
+        """
+        filename = self._get_filename(META_DATA_FILENAME)
+        with open(filename, "wt") as filehandle:
+            filehandle.write(data)
+
+    def get_user_data(self):
+        """
+        Return the appropriate meta-data for this request
+        """
+        if self.user_data:
+            return self.user_data
+        filename = self._get_filename(USER_DATA_FILENAME)
+        if not filename:
+            return None
+        with open(filename, "r") as userdata:
+            self.user_data = userdata.read()
+            return self.user_data
+        return None
+
+    def optional_redirect(self):
+        """
+        Return optional redirect, or None
+        """
+        filename = self._get_filename(REDIRECT_FILENAME)
+        if not (filename and os.path.exists(filename)):
+            return None
+        try:
+            with open(filename) as redirect:
+                content = redirect.read().splitlines()
+                return content[0]
+        except IOError:
+            return None
+        return None
+
+
+class CloudInitApp:
+    """
+    Serve cloud init files
+    """
+
+    @staticmethod
+    def _redirect_if_needed(request):
+        redirect = request.optional_redirect()
+        if redirect:
+            raise cherrypy.HTTPRedirect(redirect, 301)
+        return False
 
     @staticmethod
     def _content_type(data):
+        if not data:
+            return "text/cloud-config"
         if data.startswith("#include"):
             return "text/x-include-url"
-        elif data.startswith("## template: jinja"):
+        if data.startswith("## template: jinja"):
             return "text/jinja2"
-        else:
-            return "text/cloud-config"
+        return "text/cloud-config"
 
     @staticmethod
     def _wrap_metadata(metadata):
         return {'ds': {
                           'meta_data': metadata
-                         }
-                  }
+                       }
+                }
 
-    @cherrypy.expose
-    def user_data(self):
+    def _user_data(self, uuid=None):
         """
         Serves a static file
+        But can process a template if x-include-url
         """
-        self._init_ip()
-        self._redirect_if_needed()
-        filepath = os.path.join(PATH, "data", self.hostinfo[0],
-                                USER_DATA_FILENAME)
-        if not os.path.exists(filepath):
-            filepath = os.path.join(PATH, "data", USER_DATA_FILENAME)
-        with open(filepath, "r") as userdata:
-            data = userdata.read()
- 
-        c = CloudInitApp._content_type(data)
+        request = CloudInitRequest(cherrypy.request, uuid)
+        self._redirect_if_needed(request)
+        user_data = request.get_user_data()
 
-        cherrypy.response.headers['Content-Type'] = c
+        c__ = self._content_type(user_data)
+
+        cherrypy.response.headers['Content-Type'] = c__
         cherrypy.response.headers['Content-Disposition'] = \
             'attachment; filename="user-data"'
 
-        if c == "text/x-include-url":
-            t = Template(data)
-            metadata = self._generate_metadata()
+        if c__ == "text/x-include-url":
+            t__ = Template(user_data)
+            metadata = request.get_meta_data()
             wrapped = CloudInitApp._wrap_metadata(metadata)
-            return t.render(**wrapped)
-        else:
-            return data
+            return t__.render(**wrapped)
+        return user_data
 
-    @cherrypy.expose
-    def meta_data(self):
+    def _meta_data(self, uuid=None):
         """
         Return meta-data in YAML
         """
-        self._init_ip()
-        self._redirect_if_needed()
-
-        data = self._generate_metadata()
-
-        filepath = os.path.join(PATH, "data", data['local-hostname'], META_DATA_FILENAME)
-        if os.path.exists(filepath):
-            with open(filepath, "r") as metadata:
-                data.update(yaml.safe_load(metadata))
+        request = CloudInitRequest(cherrypy.request, uuid)
+        self._redirect_if_needed(request)
 
         cherrypy.response.headers['Content-Type'] = \
             'text/yaml'
         cherrypy.response.headers['Content-Disposition'] = \
             'attachment; filename="meta-data"'
-        return yaml.dump(data)
+        return yaml.dump(request.get_meta_data())
+
+    @staticmethod
+    def _vendor_data():
+        return ""
+
+    @cherrypy.expose
+    def user_data(self):
+        """
+        v1 api endpoint user-data
+        """
+        return self._user_data()
+
+    @cherrypy.expose
+    def meta_data(self):
+        """
+        v1 api endpoint meta-data
+        """
+        return self._meta_data()
 
     @cherrypy.expose
     def vendor_data(self):
         """
-        Return empty vendor-data
+        v1 api endpoint vendor-data
         """
-        return ""
+        return self._vendor_data()
 
     @cherrypy.expose
+    def apiv2(self, uuid=None, filetype="user-data"):
+        """
+        API endpoint v2
+        extract command from arguments
+        """
+        if filetype == "user-data":
+            return self._user_data(uuid)
+        if filetype == "meta-data":
+            return self._meta_data(uuid)
+        if filetype == "vendor-data":
+            return self._vendor_data()
+        return ""
+
+    # unused
+    # @cherrypy.expose
     def finished(self, data):
         """
         Saves additional meta-data
 
         :param data: meta-data to be added
         """
-        self._init_ip()
-        folder = os.path.join(PATH, "data", self.hostinfo[0])
-        if not os.path.exists(folder):
-            os.makedirs(folder)
-
-        with open(os.path.join(folder, META_DATA_FILENAME), "w") as fin:
-            fin.write(data)
+        request = CloudInitRequest(cherrypy.request)
+        self._redirect_if_needed(request)
+        request.save_meta_data(data)
 
 
 ROOT = CloudInitApp()
@@ -191,8 +298,12 @@ if __name__ == "__main__":
     config = {
               '/include': {
                            'tools.staticdir.on': True,
-                           'tools.staticdir.dir': os.path.join(current_dir, 'data', 'include'),
-                           'tools.staticdir.content_types': {'yml': 'text/yaml'}
+                           'tools.staticdir.dir': os.path.join(current_dir,
+                                                               'data',
+                                                               'include'),
+                           'tools.staticdir.content_types': {
+                                                             'yml': 'text/yaml'
+                                                             }
                           }
              }
     cherrypy.tree.mount(ROOT, config=config)
@@ -203,7 +314,7 @@ if __name__ == "__main__":
         ENGINE.console_control_handler.subscribe()
     try:
         ENGINE.start()
-    except Exception:
+    except Exception:  # pylint: disable=broad-except
         sys.exit(1)
     else:
         ENGINE.block()