✨ Add OTA updater script (homieiot#384)

* 🐍Add python ota updater script

* 💼 Update documentation of ota update script

* 😑 Add comments to ota updater script

* 🔮 Use 127.0.0.1:1883 as default broker setting

For the ota updater script

scripts/ota_updater/README.md

@@ -10,15 +10,33 @@ This will allow you to send an OTA update to your device.
 ## Usage
 
 ```bash
-python ./ota_update.py \
-  --broker-host "127.0.0.1" \
-  --broker-port "1883" \
-  --broker-username "" \
-  --broker-password "" \
-  --base-topic "homie/" \
-  --device-id "my-device-id" \
-  ~/my_firmware.bin
+> scripts/ota_updater/ota_updater.py -h
+usage: ota_updater.py [-h] -l BROKER_HOST -p BROKER_PORT [-u BROKER_USERNAME]
+                      [-d BROKER_PASSWORD] [-t BASE_TOPIC] -i DEVICE_ID
+                      firmware
+
+ota firmware update scirpt for ESP8226 implemenation of the Homie mqtt IoT
+convention.
+
+positional arguments:
+  firmware              path to the firmware to be sent to the device
+
+arguments:
+  -h, --help            show this help message and exit
+  -l BROKER_HOST, --broker-host BROKER_HOST
+                        host name or ip address of the mqtt broker
+  -p BROKER_PORT, --broker-port BROKER_PORT
+                        port of the mqtt broker
+  -u BROKER_USERNAME, --broker-username BROKER_USERNAME
+                        username used to authenticate with the mqtt broker
+  -d BROKER_PASSWORD, --broker-password BROKER_PASSWORD
+                        password used to authenticate with the mqtt broker
+  -t BASE_TOPIC, --base-topic BASE_TOPIC
+                        base topic of the homie devices on the broker
+  -i DEVICE_ID, --device-id DEVICE_ID
+                        homie device id
 ```
 
-All parameters are optional, except `--device-id` and the firmware path.
-Default values are the one above.
+* `BROKER_HOST` and `BROKER_PORT` defaults to 127.0.0.1 and 1883 respectively if not set.
+* `BROKER_USERNAME` and `BROKER_PASSWORD` are optional.
+* `BASE_TOPIC` defaults to `homie/` if not set

scripts/ota_updater/ota_updater.py

@@ -1 +1,153 @@
 #!/usr/bin/env python
+
+from __future__ import division, print_function
+import paho.mqtt.client as mqtt
+import base64, sys, math
+from hashlib import md5
+
+# The callback for when the client receives a CONNACK response from the server.
+def on_connect(client, userdata, flags, rc):
+    if rc != 0:
+        print("Connection Failed with result code {}".format(rc))
+        client.disconnect()
+    else:
+        print("Connected with result code {}".format(rc))
+
+    # calcluate firmware md5
+    firmware_md5 = md5(userdata['firmware']).hexdigest()
+    userdata.update({'md5': firmware_md5})
+
+    # Subscribing in on_connect() means that if we lose the connection and
+    # reconnect then subscriptions will be renewed.
+    client.subscribe("{base_topic}{device_id}/$implementation/ota/status".format(**userdata))
+    client.subscribe("{base_topic}{device_id}/$implementation/ota/enabled".format(**userdata))
+    client.subscribe("{base_topic}{device_id}/$fw/#".format(**userdata))
+
+    # Wait for device info to come in and invoke the on_message callback where update will continue
+    print("Waiting for device info...")
+
+
+# The callback for when a PUBLISH message is received from the server.
+def on_message(client, userdata, msg):
+    # decode string for python2/3 compatiblity
+    msg.payload = msg.payload.decode()
+
+    if msg.topic.endswith('$implementation/ota/status'):
+        status = int(msg.payload.split()[0])
+
+        if userdata.get("published"):
+            if status == 206: # in progress
+                # state in progress, print progress bar
+                progress, total = [int(x) for x in msg.payload.split()[1].split('/')]
+                bar_width = 30
+                bar = int(bar_width*(progress/total))
+                print("\r[", '+'*bar, ' '*(bar_width-bar), "] ", msg.payload.split()[1], end='', sep='')
+                if (progress == total):
+                    print()
+                sys.stdout.flush()
+            elif status == 304: # not modified
+                print("Device firmware already up to date with md5 checksum: {}".format(userdata.get('md5')))
+                client.disconnect()
+            elif status == 403: # forbidden
+                print("Device ota disabled, aborting...")
+                client.disconnect()
+
+    elif msg.topic.endswith('$fw/checksum'):
+        checksum = msg.payload
+
+        if userdata.get("published"):
+            if checksum == userdata.get('md5'):
+                print("Device back online. Update Successful!")
+            else:
+                print("Expecting checksum {}, got {}, update failed!".format(userdata.get('md5'), checksum))
+            client.disconnect()
+        else:
+            if checksum != userdata.get('md5'): # save old md5 for comparison with new firmware
+                userdata.update({'old_md5': checksum})
+            else:
+                print("Device firmware already up to date with md5 checksum: {}".format(checksum))
+                client.disconnect()
+
+    elif msg.topic.endswith('ota/enabled'):
+        if msg.payload == 'true':
+            userdata.update({'ota_enabled': True})
+        else:
+            print("Device ota disabled, aborting...")
+            client.disconnect()
+
+    if ( not userdata.get("published") ) and ( userdata.get('ota_enabled') ) and \
+       ( 'old_md5' in userdata.keys() ) and ( userdata.get('md5') != userdata.get('old_md5') ):
+        # push the firmware binary
+        userdata.update({"published": True})
+        topic = "{base_topic}{device_id}/$implementation/ota/firmware/{md5}".format(**userdata)
+        print("Publishing new firmware with checksum {}".format(userdata.get('md5')))
+        client.publish(topic, userdata['firmware'])
+
+
+def main(broker_host, broker_port, broker_username, broker_password, base_topic, device_id, firmware):
+    # initialise mqtt client and register callbacks
+    client = mqtt.Client()
+    client.on_connect = on_connect
+    client.on_message = on_message
+
+    # set username and password if given
+    if broker_username and broker_password:
+        client.username_pw_set(broker_username, broker_password)
+
+    # save data to be used in the callbacks
+    client.user_data_set({
+            "base_topic": base_topic,
+            "device_id": device_id,
+            "firmware": firmware
+        })
+
+    # start connection
+    print("Connecting to mqtt broker {} on port {}".format(broker_host, broker_port))
+    client.connect(broker_host, broker_port, 60)
+
+    # Blocking call that processes network traffic, dispatches callbacks and handles reconnecting.
+    client.loop_forever()
+
+
+if __name__ == '__main__':
+    import argparse
+
+    parser = argparse.ArgumentParser(
+        description='ota firmware update scirpt for ESP8226 implemenation of the Homie mqtt IoT convention.')
+
+    # ensure base topic always ends with a '/'
+    def base_topic_arg(s):
+        s = str(s)
+        if not s.endswith('/'):
+            s = s + '/'
+        return s
+
+    # specify arguments
+    parser.add_argument('-l', '--broker-host',     type=str,            required=False,
+                        help='host name or ip address of the mqtt broker', default="127.0.0.1")
+    parser.add_argument('-p', '--broker-port',     type=int,            required=False,
+                        help='port of the mqtt broker', default=1883)
+    parser.add_argument('-u', '--broker-username', type=str,            required=False,
+                        help='username used to authenticate with the mqtt broker')
+    parser.add_argument('-d', '--broker-password', type=str,            required=False,
+                        help='password used to authenticate with the mqtt broker')
+    parser.add_argument('-t', '--base-topic',      type=base_topic_arg, required=False,
+                        help='base topic of the homie devices on the broker', default="homie/")
+    parser.add_argument('-i', '--device-id',       type=str,            required=True,
+                        help='homie device id')
+    parser.add_argument('firmware', type=argparse.FileType('rb'),
+                        help='path to the firmware to be sent to the device')
+
+    # workaround for http://bugs.python.org/issue9694
+    parser._optionals.title = "arguments"
+
+    # get and validate arguments
+    args = parser.parse_args()
+
+    # read the contents of firmware into buffer
+    firmware = args.firmware.read()
+    args.firmware.close()
+
+    # Invoke the business logic
+    main(args.broker_host, args.broker_port, args.broker_username,
+         args.broker_password, args.base_topic, args.device_id, firmware)

scripts/ota_updater/requirements.txt

@@ -1 +1 @@
-paho-mqtt==1.2.3
+paho-mqtt >1.2.3,<=1.3.0