Why can`t wrtite data to InfluxDB v3 through nginx upstream?
05:54 16 Dec 2025

I am using the influxdb3-python library with InfluxDB v3. When I try to read data, everything works, but as soon as I try to write data to the DB, it throws an error:

(0)
Reason: SSLError
[SSL] unknown error (_ssl.c:1000)

On the server, I use a combination of nginx + influxdb, and everything is wrapped in Docker.

Nginx.conf:

stream {
        ssl_certificate /etc/letsencrypt/live/example.ru/fullchain.pem;
        ssl_certificate_key /etc/letsencrypt/live/example.ru/privkey.pem;
        ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;
        ssl_session_cache shared:SSL:1m;
        ssl_session_timeout 4h;
        ssl_protocols TLSv1.2 TLSv1.3;
        ssl_prefer_server_ciphers on;
        ssl_alpn h2;

        upstream influxdb_steam {
          server influx:8181;
        }

        server {
          listen 8088 ssl;
          proxy_pass influxdb_steam;
        }
}

Python code:

import time
from influxdb_client_3 import InfluxDBClient3

if __name__ == '__main__':
    try:
        clien_influx3 = InfluxDBClient3(
            token="my_token",
            host="https://example.ru:8088",
            database="myDB"
        )
        now = int(time.time())
        data = [
            {
                "measurement": "mymeasure",
                "tags": {
                    "mes": "mes-1"
                },
                "time": datetime.datetime.utcfromtimestamp(
                    now).strftime('%Y-%m-%dT%H:%M:%SZ'),
                "fields": {
                    "value": 1.0,
                }
            },
        ]
        result = clien_influx3.write(data)
    except Exception as e:
        print(e)

But if i try, it`s working:

curl -k --verbose -X POST "https://example.ru:8088/api/v2/write?bucket=myDB&org=" \
      -H "Authorization: Token my_token" \
      -H "Content-Type: text/plain; charset=utf-8" \
      --data-binary "mymeasure,mes=mes-1 value=1.0 1765869879000000000"

Versions:

Nginx 1.22.0
InfluxDB 3.5.0-core
Python 3.12
influxdb3-python 0.16.0
nginx influxdb