Create a HAProxy config file from a Docker container with a hostname as container name.

haproxy-settings-from-docker-container.py

import subprocess
import sys
import re

conf_dir = '/etc/haproxy/conf.d/'
command = ["/usr/bin/docker ps | grep " + sys.argv[1]]
p = subprocess.Popen(command, stdout=subprocess.PIPE, shell=True)
output, err = p.communicate()
d_str = output.decode("utf-8")

ports = re.findall(':([0-9]+)->([0-9]+)', d_str)
domain = re.findall('\s([\S]+)\s*$', d_str)

f = open(conf_dir + domain[0], 'w+')
f.write('listen ' + domain[0] + "\n")
f.write("\tcontimeout 5000\n\tclitimeout 50000\n\tsrvtimeout 50000\n")

listen_str = ''
backend_str = ''

for i in range(len(ports)):
        listen_str += '\tbind ' + '*:' + ''.join(ports[i][1]) + "\n"
        listen_str += '\tacl port_' + str(i) + ' dst_port ' + ''.join(ports[i][1]) + "\n"
        listen_str += '\tuse_backend backend_' +  ''.join(ports[i][0]) + " if port_" + str(i) + "\n"

        backend_str += "backend backend_" + ''.join(ports[i][0]) + "\n"
        backend_str += "\tcontimeout 5000\n\tsrvtimeout 50000\n"
        backend_str += "\tserver s1 127.0.0.1:" + ''.join(ports[i][0]) + " check\n"

f.write(listen_str)
f.write(backend_str)

f.close()

FYI this does not work with multiple domains.