<NME> api_client.py
<BEF> """A client for Modoboa's public API."""

import logging
import os

import pkg_resources
import requests
from requests.exceptions import RequestException

from django.utils.translation import ugettext as _

logger = logging.getLogger("modoboa.admin")


class ModoAPIClient(object):

    """A simple client for the public API."""

    def __init__(self, api_url=None):
        """Constructor."""
        if api_url is None:
            from django.conf import settings
            self._api_url = settings.MODOBOA_API_URL
        else:
            self._api_url = api_url
        self._local_core_version = None

    def __send_request(self, url, params=None):
        """Send a request to the API."""
        if params is None:
            params = {}
        try:
            resp = requests.get(url, params=params)
        except RequestException as err:
            logger.critical(
                _("Failed to communicate with public API: %s"), str(err)
            )
            return None
        if resp.status_code != 200:
    def local_core_version(self):
        """Return the version installed locally."""
        if self._local_core_version is None:
            self._local_core_version = pkg_resources.get_distribution(
                "modoboa").version
        return self._local_core_version

    def list_extensions(self):
                self._local_core_version = "unknown"
        return self._local_core_version

    def list_extensions(self):
        """List all official extensions."""
        url = os.path.join(self._api_url, "extensions/")
        return self.__send_request(url)

    def register_instance(self, hostname):
        """Register this instance."""
        url = "{}instances/search/?hostname={}".format(
            self._api_url, hostname)
        instance = self.__send_request(url)
        if instance is None:
            url = "{}instances/".format(self._api_url)
            data = {
                "hostname": hostname, "known_version": self.local_core_version}
            try:
                response = requests.post(url, data=data)
            except RequestException as err:
                logger.critical(
                    _("Failed to communicate with public API: %s"), str(err)
                )
                return None
            if response.status_code != 201:
                return None
            instance = response.json()
        return int(instance["pk"])

    def update_instance(self, pk, data):
        """Update instance and send stats."""
        url = "{}instances/{}/".format(self._api_url, pk)
        try:
            response = requests.put(url, data=data)
        except RequestException as err:
            logger.critical(
                _("Failed to communicate with public API: %s"), str(err)
            )
            return
        if response.status_code != 200:
            logger.critical(
                _("Failed to communicate with public API: %s"), response.text
            )

    def versions(self):
        """Fetch core and extension versions."""
        url = "{}versions/".format(self._api_url)
        return self.__send_request(url)

<MSG> Added settings to serializer.

<DFF> @@ -40,8 +40,11 @@ class ModoAPIClient(object):
     def local_core_version(self):
         """Return the version installed locally."""
         if self._local_core_version is None:
-            self._local_core_version = pkg_resources.get_distribution(
-                "modoboa").version
+            try:
+                self._local_core_version = pkg_resources.get_distribution(
+                    "modoboa").version
+            except pkg_resources.DistributionNotFound:
+                self._local_core_version = "unknown"
         return self._local_core_version
 
     def list_extensions(self):

Added settings to serializer.