Added 'ftp_proxy' environment variable support

Some bitbake recipes use FTP to fetch objects. This patch adds support
for the ftp_proxy variable to kas. Is now usable in the same manner as
the 'http_proxy' variable

Signed-off-by: Claudius Heine <ch@denx.de>

docs/devguide.rst

@@ -22,7 +22,7 @@ Just run::
 
 When you need a proxy to access the internet, add::
 
-    --build-arg http_proxy=<http_proxy> --build-arg https_proxy=<https_proxy>
+    --build-arg http_proxy=<http_proxy> --build-arg https_proxy=<https_proxy> --build-arg ftp_proxy=<ftp_proxy>
 
 to the call.
 

docs/userguide.rst

@@ -93,6 +93,7 @@ Environment variables
 +-----------------------+-----------------------------------------------------+
 | ``http_proxy``        | This overwrites the proxy configuration in the      |
 | ``https_proxy``       | configuration file.                                 |
+| ``ftp_proxy``         |                                                     |
 | ``no_proxy``          |                                                     |
 +-----------------------+-----------------------------------------------------+
 | ``GIT_PROXY_COMMAND`` | Set proxy for native git fetches. ``NO_PROXY`` is   |

kas/config.py

@@ -146,6 +146,7 @@ class Config:
                                          proxy_config.get(var_name, ''))
                 for var_name in ['http_proxy',
                                  'https_proxy',
+                                 'ftp_proxy',
                                  'no_proxy']}
 
     def get_repos(self):

kas/configschema.py

@@ -161,6 +161,9 @@ CONFIGSCHEMA = {
                 'https_proxy': {
                     'type': 'string',
                 },
+                'ftp_proxy': {
+                    'type': 'string',
+                },
                 'no_proxy': {
                     'type': 'string',
                 },