add Postgres connection validation

manifests/init.pp

@@ -7,7 +7,9 @@
 # @param comptoir_srv_dir Absolute path where Comptoir source code should be cloned, example: '/home/comptoir/Comptoir-srv'. Must be coherent with comptoir_repos_url
 # @param comptoir_revision Revision of Comptoir repos as understood by module VCSRepos, may be a branch, a tag, a SHA-1
 # @param comptoir_db_user Database username owning the database for the application
-# @param comptoir_db_name Name for the database for the application
+# @param comptoir_db_user Database username owning
+# @param comptoir_db_password PAssword for the user of the database
+# @param comptoir_db_host Name of the database host, must an FQDN or an IP address
 #
 # @example
 #   include comptoir
@@ -19,6 +21,8 @@ class comptoir (
   String $comptoir_revision            = 'master',
   String $comptoir_db_user             = 'comptoir',
   String $comptoir_db_name             = 'comptoir',
+  String $comptoir_db_password         = 'comptoir',
+  String $comptoir_db_host             = 'localhost',
 ) {
 
   # Inner variables
@@ -46,6 +50,13 @@ class comptoir (
   #   environment => [ 'HOME=/home/comptoir' ],
   # }
 
+  # TODO add a connection validation
+  postgresql_conn_validator { 'validate my postgres connection':
+    host        => $comptoir_db_host,
+    db_username => $comptoir_db_user,
+    db_password => $comptoir_db_password,
+    db_name     => $comptoir_db_name,
+  } ->
   postgresql_psql { 'Create SQL tables & procedures':
     command   => "\i ${comptoir_dir}/${_SQL_create_tables_and_procedure}",
     db        => $comptoir_db_name,