docker build -t webconnechecker:0.0.1 .
docker run -itd --rm --name webconnechecker -p 8000:8000 webconnechecker:0.0.1
# use proxy
docker run -it --rm --name webconnechecker --network host --env HTTP_PROXY="http://127.0.0.1:9999" webconnechecker:0.0.1

Reference:

HEAD requests with aiohttp is dog slow