attenuation-control: Add scripts to control the attenuation

Xmlrpc client/server application to control the digital attenuators
installed in the lava testbed.

Implements AR_VUL-64.

Signed-off-by: Thomas Klaehn <thomas.klaehn@u-blox.com>

source/attenuation_control_client/__main__.py

@@ -0,0 +1,65 @@
+#!/usr/bin/python3
+
+import argparse
+import logging
+import sys
+from xmlrpc.client import ServerProxy
+
+DEFAULT_PORT = "8231"
+
+logging.basicConfig(level=logging.INFO, format='%(levelname)s %(message)s')
+LOG = logging.getLogger("att_ctrl_client")
+
+def parse_args():
+    """Command line argument parser"""
+    parser = argparse.ArgumentParser()
+    parser.add_argument("host", help="Hostname or ip address the server is \
+                        serving on. (e.g. 'attctrl:8231 or 192.168.1.16'")
+    parser.add_argument('attenuator', help="Attenuator to be set [0..7]")
+    parser.add_argument('attenuation', help="Attenuation to be set [0.0 .. 31.5]")
+
+    return parser.parse_args()
+
+def host_port(data):
+    '''Determine hostname/address and port.
+
+    Args:
+        data (str): Hostname/address with optional port (e.g. 'localhost:1234'
+                    or '192.168.0.1').
+
+    Returns:
+        str: Hostname/address
+        str: Port
+    '''
+    tmp = data.split(":")
+    port = DEFAULT_PORT
+    host = tmp[0]
+
+    if len(tmp) > 1:
+        port = tmp[1]
+    return host, port
+
+
+def main():
+    args = parse_args()
+    host, port = host_port(args.host)
+    client = ServerProxy('http://{}:{}'.format(host, port))
+
+    try:
+        dev = int(args.attenuator)
+    except ValueError:
+        LOG.error("attenuator needs to be convertible into int.")
+        return 1
+    try:
+        val = float(args.attenuation)
+    except ValueError:
+        LOG.error("attenuation needs to be convertible into float.")
+        return 1
+
+    ret = client.set_attenuation(dev, val)
+
+    LOG.info("xmlrpcclient: set_attenuation result: {}.".format(ret))
+    return ret
+
+if __name__ == "__main__":
+    sys.exit(main())