#2. wifi AP control with ssh commands

 #3. transfer big file between rpis

experiment.py

@@ -0,0 +1,176 @@
+import paramiko
+import time
+from wifi import Cell, Scheme
+import threading
+import Queue
+import logger
+import inspect
+
+WIFI_INTERFACE     = 'wlp1s0'
+WIFI_AP            = ['rpi2', 'rpi4','rpi6',]
+WIFI_CLIENTS       = {
+    WIFI_AP[0]: 'rpi3',
+    WIFI_AP[1]: 'rpi5',
+    WIFI_AP[2]: 'rpi7',
+}
+RPI2_HOSTNAME      = 'rpi2.local'
+RPI3_HOSTNAME      = 'rpi3.local'
+RPI2_WIFI          = 'rpi2'
+RPI4_WIFI          = 'rpi4'
+RPI6_WIFI          = 'rpi6'
+TURN_ON_AP_COMMAND = 'sudo service hostapd start'
+TURN_OFF_AP_COMMAND = 'sudo service hostapd stop'
+CONNECT_WIFI       = 'sudo wpa_supplicant -Dnl80211 -iwlan0 -c/etc/wpa_supplicant/wpa_supplicant.conf'
+DEFAULT_IP_CLIENTS = '192.168.42.22'
+RPI_USERNAME       = 'pi'
+RPI_PASS           = 'inria'
+MAX_TX_RATE        = 16000 # kbits = 2 Mbytes
+TEST_TIME          = 60
+
+
+
+#============================ classes =========================================
+class Wifi_experiment(object):
+
+    def __init__(self):
+        # store params
+
+        # local variables
+        self.logger     = logger.Logger('/dev/ttyUSB3', 'one.log', 30)
+        # First test: No Wifi networks at all
+        #self._no_wifi_networks_at_all_test()
+        # Second test: rpi2 wifi network activated
+        #self._onlyrpi2wifinetwork_test()
+        # Third test: 50% traffic level one wifi network
+        #self._onlyrpi2wifiaveragetraffic_test()
+
+
+
+    #======================== public ==========================================
+
+    #======================== private =========================================
+
+    #======== principal functions
+
+    def _do_test(self, parameters):
+        # turn on and off the AP
+        self._set_wifi_networks(parameters['active_networks'], parameters['disable_networks'])
+        file_tranfers         = []
+        if parameters['traffic']!=0:
+            # make sure of wifi clients connection
+            self._set_wifi_clients(parameters['active_networks'])
+            # run file tranfers
+            for n in parameters['active_networks']:
+                file_tranfers    += threading.Thread(
+                    target        = self._send_file,
+                    args          = ('{0}.local'.format(n), parameters['traffic'], TEST_TIME)
+                )
+            for f in file_tranfers:
+                f.start()
+        self.logger._change_experiment('{0}.log'.format(parameters['name']))
+
+
+    '''
+    def _no_wifi_networks_at_all_test(self):
+        active_networks      = []
+        disable_networks     = WIFI_AP
+        self._set_wifi_networks(active_networks, disable_networks)
+        #
+        self.logger._change_experiment('{0}.log'.format(inspect.stack()[0][3]))
+
+    def _onlyrpi2wifinetwork_test(self):
+
+        self._send_sshcommand(RPI2_HOSTNAME, TURN_ON_AP_COMMAND, 0)
+        self._waitforwifinetworkon(RPI2_WIFI)
+        print 'listo'
+        # TO_DO: algo para leer puerto serial y todo eso
+
+    def _onlyrpi2wifiaveragetraffic_test(self):
+        # check if rpi3 connected to rpi2 wifi
+        self._send_sshcommand(RPI3_HOSTNAME, CONNECT_WIFI, 0)
+        self._wait_until_wifi_connection(RPI3_HOSTNAME)
+        # at this point rp3 and rp2 are ready to exchange information
+        self._send_file(RPI2_HOSTNAME, 1, 20)
+        # TO_DO: algo para leer puerto serial y todo eso
+    '''
+    #========= misc
+
+    def _set_wifi_networks(self, active_networks, disable_networks):
+        for n in active_networks:
+            self._send_sshcommand('{0}.local'.format(n), TURN_ON_AP_COMMAND, 0)
+            self._waitforwifinetworkon(n)
+
+        for n in disable_networks:
+            self._send_sshcommand('{0}.local'.format(n), TURN_OFF_AP_COMMAND, 0)
+            self._waitforwifinetworkoff(n)
+
+    def _set_wifi_clients(self, active_networks):
+        for n in active_networks:
+            self._send_sshcommand('{0}.local'.format(WIFI_CLIENTS[n]), CONNECT_WIFI, 0)
+            self._wait_until_wifi_connection('{0}.local'.format(WIFI_CLIENTS[n]))
+
+    def _send_sshcommand(self, hostname, command, time_out):
+        result     = []
+        ssh_session     = paramiko.SSHClient()
+        ssh_session.load_system_host_keys()
+        ssh_session.connect(hostname, username=RPI_USERNAME, password=RPI_PASS)
+        if time_out != 0:
+            stop_queue            = Queue.Queue()
+            exec_command_thread   = threading.Thread(
+                target            = self._loop_command,
+                args              = (ssh_session, command, stop_queue)
+            )
+            exec_command_thread.start()
+            time.sleep(time_out)
+            stop_queue.put('stop')
+            self._send_sshcommand(hostname, 'sudo killall ssh', 0)
+            exec_command_thread.join()
+        else:
+            ssh_result      = ssh_session.exec_command(command)
+            result   += [ssh_result[1].read(),]
+            result   += [ssh_result[2].read(),]
+            ssh_session.close()
+            return result
+
+    def _loop_command(self, ssh_session, command, stop_queue):
+        while stop_queue.empty():
+            stdin,stdout,stderr = ssh_session.exec_command(command)
+            out = stdout.read()
+
+
+    def _waitforwifinetworkon(self, ssid):
+        goOn  = True
+        while goOn:
+            wifi_networks    = Cell.all(WIFI_INTERFACE)
+            for w in wifi_networks:
+                if w.ssid == ssid:
+                    goOn     = False
+                    break
+
+    def _waitforwifinetworkoff(self, ssid):
+        goOn  = True
+        while goOn:
+            wifi_networks    = Cell.all(WIFI_INTERFACE)
+            goOn             = False
+            for w in wifi_networks:
+                if w.ssid == ssid:
+                    goOn     = True
+                    break
+    def _wait_until_wifi_connection(self, hostname):
+        goOn  = True
+        while goOn:
+            result = self._send_sshcommand(hostname, 'hostname -I',0)
+            if result[0].find(DEFAULT_IP_CLIENTS) != -1:
+                goOn    = False
+            else:
+                time.sleep(0.2)
+
+    def _send_file(self, hostname_tx, percentage_rate, time_out):
+        command    = 'sshpass -p "inria" scp -l {0} /home/pi/Documents/file_to_send.img [email protected]:/home/pi/Documents/'.format(int(MAX_TX_RATE*percentage_rate))
+        ssh_result = self._send_sshcommand(hostname_tx, command, time_out)
+        return ssh_result
+
+#============================ main ============================================
+
+if __name__ == '__main__':
+    experiment = Wifi_experiment()