From de749526dae8e05db00ffd3d3af0323cef0efcdb Mon Sep 17 00:00:00 2001
From: Benjamin Dweck <bjdweck@gmail.com>
Date: Fri, 29 Jan 2021 14:56:07 +0200
Subject: [PATCH] can update device info on each syncthing instance with the
 other devices' hostnames

---
 docker-compose.test.yml               |  4 ++++
 syncthing_monitor/__main__.py         | 28 ++++++++++++++++++++++-----
 syncthing_monitor/etcd_client.py      | 18 +++++++++++++----
 syncthing_monitor/syncthing_client.py | 16 +++++++--------
 4 files changed, 49 insertions(+), 17 deletions(-)

diff --git a/docker-compose.test.yml b/docker-compose.test.yml
index abdd40d..d3c4c37 100644
--- a/docker-compose.test.yml
+++ b/docker-compose.test.yml
@@ -20,6 +20,8 @@ services:
     volumes:
       - sync1config:/config
       - etcd
+    environment:
+      - SYNCTHING_HOSTNAME=sync1
     networks:
       - syncnet
 
@@ -42,6 +44,8 @@ services:
       - etcd
     volumes:
       - sync2config:/config
+    environment:
+      - SYNCTHING_HOSTNAME=sync2
     networks:
       - syncnet
 
diff --git a/syncthing_monitor/__main__.py b/syncthing_monitor/__main__.py
index 61fe53e..6c39d01 100644
--- a/syncthing_monitor/__main__.py
+++ b/syncthing_monitor/__main__.py
@@ -1,3 +1,6 @@
+import os
+import time
+
 import syncthing_monitor.config_xml as xml
 from .etcd_client import EtcdClient
 from .syncthing_client import SyncthingClient
@@ -16,12 +19,27 @@ def loop(gui_port="8384", host="sync"):
     my_device_id = syncthing.get_my_device_id()
     print("Found Device ID: {0}".format(my_device_id))
 
-    etcd = EtcdClient('etcd')
-    etcd.append_device_id(my_device_id)
-    device_ids = etcd.get_device_list()
+    my_syncthing_hostname = os.getenv('SYNCTHING_HOSTNAME')
 
-    syncthing.add_devices(device_ids)
-    syncthing.print_config()
+    etcd = EtcdClient('etcd')
+    updater = Updater(etcd, syncthing)
+    etcd.register_device_update_handler(updater.update_devices)
+    etcd.append_device_id(my_device_id, my_syncthing_hostname)
+
+    while True:
+        time.sleep(1)
+
+
+class Updater:
+    def __init__(self, etcd, syncthing):
+        self.etcd = etcd
+        self.syncthing = syncthing
+
+    # noinspection PyUnusedLocal
+    def update_devices(self, event):
+        device_list = self.etcd.get_device_list()
+        self.syncthing.add_devices(device_list)
+        self.syncthing.print_config()
 
 
 if __name__ == "__main__":
diff --git a/syncthing_monitor/etcd_client.py b/syncthing_monitor/etcd_client.py
index 0cb14ba..6035cb4 100644
--- a/syncthing_monitor/etcd_client.py
+++ b/syncthing_monitor/etcd_client.py
@@ -12,18 +12,25 @@ class EtcdClient:
         self.etcd = etcd3.client(host=host, port=port)
 
     def load_cluster_info(self):
-        raw_value, meta = self.etcd.get(CLUSTER_INFO_KEY)
+        raw_value = self.etcd.get(CLUSTER_INFO_KEY)[0]
         if raw_value is None:
             return {'devices': []}
         return json.loads(raw_value)
 
     @retry
-    def append_device_id(self, device_id):
+    def append_device_id(self, device_id, hostname):
         with self.etcd.lock('syncthing_monitor'):
             cluster_info = self.load_cluster_info()
 
-            if not any(device_id in element for element in cluster_info['devices']):
-                cluster_info['devices'].append(device_id)
+            if any(device_id in device['id'] for device in cluster_info['devices']):
+                return
+
+            new_device = {
+                'id': device_id,
+                'hostname': hostname
+            }
+
+            cluster_info['devices'].append(new_device)
 
             print("Updating etcd value for '{0}': {1}".format(CLUSTER_INFO_KEY, json.dumps(cluster_info)))
             self.etcd.put(CLUSTER_INFO_KEY, json.dumps(cluster_info))
@@ -33,3 +40,6 @@ class EtcdClient:
         device_list = self.load_cluster_info()['devices']
         print("Obtained device_list devices from etcd: {0}".format(json.dumps(device_list)))
         return device_list
+
+    def register_device_update_handler(self, device_update_handler):
+        self.etcd.add_watch_callback(CLUSTER_INFO_KEY, device_update_handler)
diff --git a/syncthing_monitor/syncthing_client.py b/syncthing_monitor/syncthing_client.py
index 0874c1a..b29721c 100644
--- a/syncthing_monitor/syncthing_client.py
+++ b/syncthing_monitor/syncthing_client.py
@@ -19,17 +19,17 @@ class SyncthingClient:
         response = requests.get(self.make_url("/rest/system/status"), headers=self.headers)
         return json.loads(response.content)["myID"]
 
-    def add_devices(self, device_ids):
-        for device_id in device_ids:
-            self.add_device(device_id)
+    def add_devices(self, device_list):
+        for device in device_list:
+            self.add_device(device)
 
-    def add_device(self, device_id):
+    def add_device(self, device):
         post_data = {
-            "deviceID": device_id,
-            "name": "Laptop",
+            "deviceID": device['id'],
+            "name": device['hostname'],
             "addresses": [
                 "dynamic",
-                "tcp://192.168.1.2:22000"
+                "tcp://{0}:22000".format(device['hostname'])
             ],
             "compression": "metadata",
             "certName": "",
@@ -48,7 +48,7 @@ class SyncthingClient:
         response = requests.post(self.make_url("/rest/config/devices"),
                                  headers=self.headers, data=json.dumps(post_data))
 
-        print("Attempt to add device {0} to syncthing: {1}".format(device_id, response.content))
+        print("Attempt to add device {0} to syncthing: {1}".format(device, response.content))
 
     @retry
     def print_config(self):