Tell NetworkManager not to manage resolv.conf

- Done properly by Quattor
- Without this mod, resolv.conf may be rebuild with an unappropriate content at each reboot

Fixes #153

os/network/config.pan

@@ -9,6 +9,7 @@ include { 'components/network/config' };
 include { 'quattor/functions/network' };
 
 "/system/network/hostname" ?= HOSTNAME;
+"/system/network/realhostname" ?= if ( is_defined(REAL_HOSTNAME) ) REAL_HOSTNAME else null;
 "/system/network/domainname" ?= DOMAIN;
 "/system/network/nameserver" ?= NAMESERVERS;
 
@@ -18,5 +19,11 @@ variable NETWORK_DEFAULT_GATEWAY ?= null;
 
 '/system/network/interfaces' ?= copy_network_params(NETWORK_PARAMS);
 
+
+# Disable management of resolv.conf by NetworkManager (EL8+)
+include if ( (OS_VERSION_PARAMS['family'] == 'el') && (OS_VERSION_PARAMS['majorversion'] >= "8") ) 'os/network/network_manager';
+
+
+# Ste-specific configuration, if any
 variable DEBUG = debug(OBJECT+' : OS_NETWORK_CONFIG_SITE='+to_string(OS_NETWORK_CONFIG_SITE));
 include { OS_NETWORK_CONFIG_SITE };

os/network/network_manager.pan

@@ -0,0 +1,12 @@
+unique template os/network/network_manager;
+
+include 'os/network/network_manager_schema';
+
+include 'components/metaconfig/config';
+prefix '/software/components/metaconfig/services/{/etc/NetworkManager/conf.d/99-quattor.conf}';
+'module' = 'tiny';
+bind '/software/components/metaconfig/services/{/etc/NetworkManager/conf.d/99-quattor.conf}/contents' = network_manager_configuration;
+
+# Disable management of resolv.conf by NM
+'contents/main/dns' = 'none';
+

os/network/network_manager_schema.pan

@@ -0,0 +1,9 @@
+declaration template os/network/network_manager_schema;
+
+type network_manager_config_main = {
+    'dns' ? choice('none')
+};
+
+type network_manager_configuration = {
+    'main' : network_manager_config_main
+};