syntax errors

[nodemanager.git] / tools.py

diff --git a/tools.py b/tools.py
index afd55bd..dbfa55f 100644 (file)
--- a/tools.py
+++ b/tools.py
@@ -289,3 +289,42 @@ def get_sliver_ip(slice_name):
 
     return None
 
+### this returns the kind of virtualization on the node
+# either 'vs' or 'lxc'
+# also caches it in /etc/planetlab/virt for next calls
+# could be promoted to core nm if need be
+virt_stamp="/etc/planetlab/virt"
+def get_node_virt ():
+    try:
+        return file(virt_stamp).read().strip()
+    except:
+        pass
+    logger.log("Computing virt..")
+    try: 
+        if subprocess.call ([ 'vserver', '--help' ]) ==0: virt='vs'
+        else:                                             virt='lxc'      
+    except:
+        virt='lxc'
+    with file(virt_stamp,"w") as f:
+        f.write(virt)
+    return virt
+
+# how to run a command in a slice
+# now this is a painful matter
+# the problem is with capsh that forces a bash command to be injected in its exec'ed command
+# so because lxcsu uses capsh, you cannot exec anything else than bash
+# bottom line is, what actually needs to be called is
+# vs:  vserver exec slicename command and its arguments
+# lxc: lxcsu slicename "command and its arguments"
+# which, OK, is no big deal as long as the command is simple enough, 
+# but do not stretch it with arguments that have spaces or need quoting as that will become a nightmare
+def command_in_slice (slicename, argv):
+    virt=get_node_virt()
+    if virt=='vs':
+        return [ 'vserver', slicename, 'exec', ] + argv
+    elif virt=='lxc':
+        # wrap up argv in a single string for -c
+        return [ 'lxcsu', slicename, ] + [ " ".join(argv) ]
+    logger.log("command_in_slice: WARNING: could not find a valid virt")
+    return argv
+