systemd unit for haproxy running in docker container

haproxy.service

[Unit]
Description=Haproxy container
After=docker.service
Requires=docker.service
ConditionFileNotEmpty=/etc/haproxy/haproxy.cfg

[Service]
TimeoutStartSec=0
Restart=always
Environment=CONFIG_DIR=/etc/haproxy
ExecStartPre=-/usr/bin/docker stop %n
ExecStartPre=-/usr/bin/docker rm %n
ExecStartPre=/usr/bin/docker pull haproxy
ExecStart=/usr/bin/docker run \
    --rm \
    --name %n \
    --net=host \
    -v ${CONFIG_DIR}:${CONFIG_DIR} \
    haproxy \
    haproxy -f ${CONFIG_DIR}/haproxy.cfg

[Install]
WantedBy=multi-user.target

# To reload config use "docker kill -s HUP haproxy.service"