add Dockerfile and python script

Dockerfile

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+# Verwenden Sie ein offizielles Python-Image als Basis
+FROM python:3.12-alpine
+
+# Arbeitsverzeichnis im Container festlegen
+WORKDIR /app
+
+RUN pip install --upgrade pip
+
+# Installieren Sie die benötigten Python-Bibliotheken
+RUN pip install requests
+
+# Führen Sie das Python-Skript aus, wenn der Container gestartet wird
+CMD ["python", "/app/Nulleinspeisung.py"]
+

Nulleinspeisung.py

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+#!/usr/bin/env python3
+
+"""
+Nulleinspeisung Control Script for Hoymiles Wechselrichter with OpenDTU and Shelly3EM Pro
+Originally forked from: https://github.com/Selbstbau-PV/Selbstbau-PV-Hoymiles-nulleinspeisung-mit-OpenDTU-und-Shelly3EM
+
+This script is a modified version, tailored for specific use-cases and enhancements.
+All original work and its credits belong to the authors of the referenced repository.
+"""
+
+import requests, time, sys
+from requests.auth import HTTPBasicAuth
+
+# User Configuration: Replace with your specific details
+serial = "<SERIAL_NUMBER>"  # Serial number of Hoymiles Wechselrichter
+maximum_wr = <MAX_OUTPUT>  # Maximum output of the Wechselrichter (Watts)
+minimum_wr = <MIN_OUTPUT>  # Minimum output of the Wechselrichter (Watts)
+
+# OpenDTU Configuration: Replace with your OpenDTU details
+dtu_ip = '<OPEN_DTU_IP>'
+dtu_user = '<OPEN_DTU_USERNAME>'
+dtu_password = '<OPEN_DTU_PASSWORD>'
+
+# Shelly Device Configuration: Replace with your Shelly 3EM Pro IP
+shelly_ip = '<SHELLY_IP>'
+
+while True:
+    time.sleep(1)  # Sleep for 1 second
+
+    try:
+        # Retrieve data from OpenDTU REST API and parse it into JSON format
+        dtu_response = requests.get(f'http://{dtu_ip}/api/livedata/status/inverters').json()
+
+        # Extract specific data from the JSON response
+        reachable = dtu_response['inverters'][0]['reachable']  # Is DTU reachable?
+        producing = int(dtu_response['inverters'][0]['producing'])  # Is the Wechselrichter producing?
+        old_limit = int(dtu_response['inverters'][0]['limit_absolute'])  # Old limit
+        power_dc = dtu_response['inverters'][0]['AC']['0']['Power DC']['v']  # DC power from panels
+        power_ac = dtu_response['inverters'][0]['AC']['0']['Power']['v']  # AC power output to grid (Watts)
+    except:
+        print('Error retrieving data from OpenDTU')
+
+    try:
+        # Retrieve data from Shelly 3EM REST API
+        shelly_response = requests.get(f'http://{shelly_ip}/rpc/Shelly.GetStatus')
+
+        if shelly_response.status_code == 200:
+            shelly_data = shelly_response.json()
+            total_act_power = shelly_data['em:0']['total_act_power']  # Total active power
+        else:
+            print(f"Shelly request failed with status code: {shelly_response.status_code}")
+
+        grid_consumption = total_act_power - 100  # Total grid consumption (all phases)
+    except:
+        print('Error retrieving data from Shelly Pro3EM')
+
+    # Calculate and display power values
+    print(f'\nGrid Consumption: {round(grid_consumption, 1)} W, Production: {round(power_ac, 1)} W, Total Consumption: {round(grid_consumption + power_ac, 1)} W')
+
+    if reachable:
+        # Calculate new limit in Watts
+        new_limit = grid_consumption + old_limit - 5
+
+        # Check and adjust the new limit against maximum and minimum thresholds
+        if new_limit > maximum_wr:
+            new_limit = maximum_wr
+            print(f'Setpoint to maximum: {maximum_wr} W')
+        elif new_limit < minimum_wr:
+            new_limit = minimum_wr
+            print(f'Setpoint to minimum: {minimum_wr} W')
+        else:
+            print(f'Calculated Setpoint: {round(grid_consumption, 1)} W + {round(old_limit, 1)} W - 5 W = {round(new_limit, 1)} W')
+
+        # Update the inverter limit if it has changed
+        if new_limit != old_limit:
+            print(f'Setting inverter limit from {round(old_limit, 1)} W to {round(new_limit, 1)} W... ', end='')
+            try:
+                # Send the new limit to the inverter
+                dtu_limit_response = requests.post(
+                    url=f'http://{dtu_ip}/api/limit/config',
+                    data=f'data={{"serial":"{serial}", "limit_type":0, "limit_value":{new_limit}}}',
+                    auth=HTTPBasicAuth(dtu_user, dtu_password),
+                    headers={'Content-Type': 'application/x-www-form-urlencoded'}
+                )
+                print(f'Configuration sent ({dtu_limit_response.json()["type"]})')
+            except:
+                print('Error sending configuration')
+
+    sys.stdout.flush()  # Flush cached messages to stdout
+    time.sleep(5)  # Sleep for 5 seconds