new: [apache] will detect efficiently changes and elegantly reload on configuration files modification.

apache/hooks/pre_deploy

@@ -0,0 +1,8 @@
+#!/bin/bash
+## Should be executable N time in a row with same result.
+
+set -e
+
+. lib/common
+
+apache_config_hash || exit 1

apache/lib/common

@@ -510,3 +510,15 @@ $(__vhost_creds_statement | prefix "    ")
 
 EOF
 }
+
+
+apache_config_hash() {
+    debug "Adding config hash to enable recreating upon config change."
+    config_hash=$(find "$SERVICE_CONFIGSTORE/etc/apache2/sites-enabled" \
+                       -name \*.conf -exec md5sum {} \; | md5_compat) || exit 1
+    init-config-add "
+$MASTER_BASE_SERVICE_NAME:
+  labels:
+    - compose.config_hash=$config_hash
+"
+}