add ability to conditionally enable tmpfs based on minimum ram availability.

3 files changed, 12 insertions, 3 deletions

diff --git a/etc/mock/defaults.cfg b/etc/mock/defaults.cfg
index 626ef99..802f4c3 100644
--- a/etc/mock/defaults.cfg
+++ b/etc/mock/defaults.cfg
@@ -66,7 +66,7 @@
 # config_opts['plugin_conf']['bind_mount_opts']['dirs'].append(('/host/path', '/bind/mount/path/in/chroot/' ))
 #
 # config_opts['plugin_conf']['tmpfs_enable'] = False
-# config_opts['plugin_conf']['tmpfs_opts'] = {}
+# config_opts['plugin_conf']['tmpfs_opts'] = {'required_ram_mb': 1024}
 
 #############################################################################
 #
diff --git a/py/mock.py b/py/mock.py
index bf0d616..d27d73e 100755
--- a/py/mock.py
+++ b/py/mock.py
@@ -240,7 +240,7 @@ def setup_default_config_opts(config_opts, unprivUid):
                 # ('/another/host/path', '/another/bind/mount/path/in/chroot/'),
                 ]},
             'tmpfs_enable': False,
-            'tmpfs_opts': {},
+            'tmpfs_opts': {'required_ram_mb': 900},
             }
 
     # dependent on guest OS
diff --git a/py/mock/plugins/tmpfs.py b/py/mock/plugins/tmpfs.py
index 74c39a1..4896d26 100644
--- a/py/mock/plugins/tmpfs.py
+++ b/py/mock/plugins/tmpfs.py
@@ -15,7 +15,16 @@ requires_api_version = "1.0"
 # plugin entry point
 decorate(traceLog())
 def init(rootObj, conf):
-    Tmpfs(rootObj, conf)
+    system_ram_bytes = os.sysconf(os.sysconf_names['SC_PAGE_SIZE']) * os.sysconf(os.sysconf_names['SC_PHYS_PAGES'])
+    system_ram_mb = system_ram_bytes / (1024 * 1024)
+    if system_ram_mb > conf['required_ram_mb']:
+        Tmpfs(rootObj, conf)
+    else:
+        getLog().warning("Tmpfs plugin disabled. "
+            "System does not have the required amount of RAM to enable the tmpfs plugin. "
+            "System has %sMB RAM, but the config specifies the minimum required is %sMB RAM. " 
+            % 
+            (system_ram_mb, conf['required_ram_mb']))
 
 # classes
 class Tmpfs(object):