feat: ability to modify bind

Dockerfile

@@ -27,5 +27,6 @@ ENV ALLOW_RESTARTS=0 \
     SYSTEM=0 \
     TASKS=0 \
     VERSION=1 \
-    VOLUMES=0
+    VOLUMES=0 \
+    BIND=":2375"
 COPY haproxy.cfg /usr/local/etc/haproxy/haproxy.cfg

haproxy.cfg

@@ -40,7 +40,7 @@ backend dockerbackend
     server dockersocket $SOCKET_PATH
 
 frontend dockerfrontend
-    bind :2375
+    bind $BIND
     http-request deny unless METH_GET || { env(POST) -m bool }
     http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/containers/[a-zA-Z0-9_.-]+/((stop)|(restart)|(kill)) } { env(ALLOW_RESTARTS) -m bool }
     http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/auth } { env(AUTH) -m bool }