collector.py

#!/usr/bin/env python3

import requests, json, logging, time, psycopg2, signal, sys
from psycopg2.extras import execute_values

CHUNK_SIZE = 96
INTERVAL = 10  # fetch interval in seconds
LOG_LEVEL = logging.ERROR
URL = "http://inverter/solar_api/v1/GetPowerFlowRealtimeData.fcgi"

logging.basicConfig(level=LOG_LEVEL)

db_conn = psycopg2.connect("dbname='home' user='postgres'")
db_cursor = db_conn.cursor()

chunk = []


def fetch():
    resp = requests.get(url=URL).json()

    sample = {
        "time": int(time.time()),
        "prod": resp["Body"]["Data"]["Site"]["P_PV"] or 0,
        "load": round(resp["Body"]["Data"]["Site"]["P_Load"]) * -1,
        # "grid": round(resp['Body']['Data']['Site']['P_Grid'])
    }
    logging.debug("sample: %s", sample)
    chunk.append(sample)


def insert():
    columns = chunk[0].keys()
    values_list = [tuple([sample[c] for c in columns]) for sample in chunk]
    execute_values(
        db_cursor,
        f'INSERT INTO electricity ({",".join(columns)}) VALUES %s',
        values_list,
    )
    db_conn.commit()
    logging.info("inserted %d samples", len(chunk))


def exit_handler(signal_received, frame):
    logging.warning("Exiting on signal")
    if len(chunk) > 0:
        insert()
    db_conn.close()
    sys.exit(0)


if __name__ == "__main__":
    signal.signal(signal.SIGINT, exit_handler)

    while True:
        try:
            fetch()
        except Exception as e:
            logging.error(f"{__file__}: Error fetching data\n{e}")

        if len(chunk) == CHUNK_SIZE:
            insert()
            chunk = []

        time.sleep(INTERVAL)