Refactor MQTT client initialization to validate host and port, and add connection testing; move command execution to a new utility module

hasspy.service

@@ -1,6 +1,6 @@
 [Unit]
 Description=Hasspy
-After=network.target
+After=network-online.target
 
 [Service]
 Type=simple

hasspy/mqtt.py

@@ -2,16 +2,18 @@ import io
 import json
 import logging
 import re
+import time
 from datetime import datetime, timezone
 from pathlib import Path
-from subprocess import run
 from threading import Thread, Timer
-from typing import Any, Mapping, Tuple
+from typing import Any, Mapping
 
 from paho.mqtt.client import Client, MQTTMessage, MQTTMessageInfo
 from paho.mqtt.enums import CallbackAPIVersion, MQTTErrorCode
 from PIL import Image
 
+from .utils import run_command, test_connection
+
 log = logging.getLogger(__name__)
 
 
@@ -31,6 +33,17 @@ class HassClient(Client):
 
         self.cover = ""
 
+        if not isinstance(self.config.get("host"), str):
+            log.error("Host was not set correctly")
+            return
+
+        if not isinstance(self.config.get("port"), int):
+            log.error("Port was not set correctly")
+            return
+
+        while not test_connection(self.config["host"], self.config["port"]):
+            time.sleep(5)
+
         self.connect()
 
     def connect(self, *args: Any, **kwargs: Any) -> MQTTErrorCode:
@@ -38,7 +51,7 @@ class HassClient(Client):
         self.will_set(self.availability_topic, "offline", retain=True)
 
         return super().connect(
-            self.config.get("host", ""), self.config.get("port", 1883)
+            self.config.get("host", ""), self.config.get("port", 1883), *args, **kwargs
         )
 
     def publish(self, *args: Any, **kwargs: Any) -> MQTTMessageInfo:
@@ -413,11 +426,3 @@ class HassUserClient(HassClient):
 
         by.seek(0)
         self.publish(self.cover_topic, by.read())
-
-
-def run_command(cmd: list[str]) -> Tuple[int, str]:
-    proc = run(cmd, capture_output=True)
-    if proc.returncode != 0:
-        return proc.returncode, ""
-
-    return proc.returncode, proc.stdout.decode("utf-8")

hasspy/utils.py

@@ -0,0 +1,28 @@
+import logging
+import socket
+from subprocess import run
+from typing import Tuple
+
+log = logging.getLogger(__name__)
+
+
+def run_command(cmd: list[str]) -> Tuple[int, str]:
+    log.debug(f"Running command {' '.join(cmd)}")
+    proc = run(cmd, capture_output=True)
+    if proc.returncode != 0:
+        return proc.returncode, ""
+
+    return proc.returncode, proc.stdout.decode("utf-8")
+
+
+def test_connection(host: str, port: int) -> bool:
+    log.debug(f"Testing connection to {host}:{port}")
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    sock.settimeout(1)
+    try:
+        sock.connect((host, port))
+        sock.close()
+        return True
+    except socket.error:
+        log.warning(f"Could not reach {host}:{port}")
+        return False