erp5: automatically reload backend apaches when configuration changes

Introduce an service to tell apache to reload its config.
This uses `hash-files` feature of slapos.cookbook:wrapper to get this
process restarted everytime something change in apache configuration
files.
This service wait forever to prevent reloading apache everytime slapos
node instance is running but only when something actually changed.

stack/erp5/buildout.hash.cfg

@@ -66,7 +66,7 @@ md5sum = 0969fbb25b05c02ef3c2d437b2f4e1a0
 
 [template]
 filename = instance.cfg.in
-md5sum = be1466bfce26211e1f0b9e5cee47fe44
+md5sum = 0ef032bb7111930c4beb01f2ecd3478a
 
 [monitor-template-dummy]
 filename = dummy.cfg
@@ -86,7 +86,7 @@ md5sum = d1257e7e942307be0a79e34aa4320e9f
 
 [template-balancer]
 filename = instance-balancer.cfg.in
-md5sum = f0fd49c7d6d9f7c6936afba0d18b7691
+md5sum = c880831c2b941c38417c647f8c01e243
 
 [template-haproxy-cfg]
 filename = haproxy.cfg.in

stack/erp5/instance-balancer.cfg.in

@@ -225,6 +225,18 @@ wait-for-files =
   ${apache-conf-ssl:cert}
   ${apache-conf-ssl:key}
 
+[{{ section('apache-reload-graceful') }}]
+recipe = slapos.cookbook:wrapper
+wrapper-path = ${directory:services}/apache-graceful-reload
+command-line =
+  {{ parameter_dict['bash'] }}/bin/bash -c "${apache-graceful:output} &&
+  {{ parameter_dict['coreutils'] }}/bin/sleep infinity"
+hash-files =
+  ${apache-conf-ssl:cert}
+  ${apache-conf-ssl:key}
+  ${apache-conf:rendered}
+  ${apache:wrapper-path}
+
 [apache-graceful]
 recipe = collective.recipe.template
 input = inline:

stack/erp5/instance.cfg.in

@@ -56,6 +56,9 @@ openssl-location = {{ openssl_location }}
 apache = {{ apache_location }}
 openssl = {{ openssl_location }}
 haproxy = {{ haproxy_location }}
+bash = {{ bash_location }}
+coreutils = {{ coreutils_location }}
+bin-directory = {{ bin_directory }}
 apachedex-location = {{ bin_directory }}/apachedex
 run-apachedex-location = {{ bin_directory }}/runApacheDex
 promise-check-apachedex-result = {{ bin_directory }}/check-apachedex-result