format: add optional knowledge of a "void"/minimal file

Signed-off-by: Jan Pokorný <jpokorny@redhat.com>

3 files changed, 23 insertions, 0 deletions

diff --git a/format.py b/format.py
index 73b4c7e..002d265 100644
--- a/format.py
+++ b/format.py
@@ -335,6 +335,7 @@ class SimpleFormat(Format):
     """This is what most of the format classes want to subclass"""
     native_protocol = BYTESTRING = Protocol('bytestring')
     FILE = Protocol('file')
+    void_file = '/dev/null'  # XXX not multi-platform
 
     def __init__(self, protocol, *args, **kwargs):
         """Format constructor, i.e., object = concrete uniformat data"""
diff --git a/formats/cib.py b/formats/cib.py
index 574ae85..d05dfa5 100644
--- a/formats/cib.py
+++ b/formats/cib.py
@@ -5,7 +5,11 @@
 """Pacemaker configuration system/Cluster Information Base (CIB) format"""
 __author__ = "Jan Pokorný <jpokorny @at@ Red Hat .dot. com>"
 
+from os.path import dirname, isabs, join
+from sys import modules
+
 from ..format import XML
+from ..utils import classproperty
 
 
 class cib(XML):
@@ -19,6 +23,15 @@ class cib(XML):
         XML.ETREE: 'pacemaker-1.2.rng'
     }
 
+    _void_file = 'pacemaker-1.2.minimal'
+
+    @classproperty
+    def void_file(cls):
+        if not isabs(cls._void_file):
+            cls._void_file = join(dirname(modules[cls.__module__].__file__),
+                                  cls.root, cls._void_file)
+        return cls._void_file
+
 
 class cib_prelude(cib):
     """Private, "unfinished" pacemaker-based cluster stack configuration
diff --git a/formats/cib/pacemaker-1.2.minimal b/formats/cib/pacemaker-1.2.minimal
new file mode 100644
index 0000000..e09b671
--- /dev/null
+++ b/formats/cib/pacemaker-1.2.minimal
@@ -0,0 +1,9 @@
+<cib validate-with="pacemaker-1.2" admin_epoch="0" epoch="0" num_updates="0">
+  <configuration>
+    <crm_config/>
+    <nodes/>
+    <resources/>
+    <constraints/>
+  </configuration>
+  <status/>
+</cib>