LXC: adapt hv for newer lxc userspace tools

Currently hv_lxc depends on the behavior and output of older LXC tools,
which have since changed, making it unable to function in current
distributions (e.g. Debian wheezy).

Adapt the tools and expectation for the output and make it into a
working state again, at least for LXC 0.8.0.

LXC tools seem to be split into two categories: the actual, binary lxc
tools, plus a set of shell scripts to provide a higher-level interface.
Ganeti doesn't need the latter and the shell scripts make some
assumptions (like /var/lib/lxc) so remove the only reference to such a
shell script (lxc-ls).

While at it, remove a few comments about "current (Spring 2010)
distributions" that do not apply anymore.

This is a backwards-incompatible change, meaning it won't work on
systems with older LXC userspace. However, hv_lxc is experimental anyway
and there's virtually no documentation about it in the tree.

Signed-off-by: Faidon Liambotis <paravoid@debian.org>
Reviewed-by: Guido Trotter <ultrotter@google.com>

diff --git a/lib/hypervisor/hv_lxc.py b/lib/hypervisor/hv_lxc.py
index 2339034..d8ba8a8 100644 (file)
--- a/lib/hypervisor/hv_lxc.py
+++ b/lib/hypervisor/hv_lxc.py
@@ -40,14 +40,6 @@ from ganeti.errors import HypervisorError
 class LXCHypervisor(hv_base.BaseHypervisor):
   """LXC-based virtualization.
 
-  Since current (Spring 2010) distributions are not yet ready for
-  running under a container, the following changes must be done
-  manually:
-    - remove udev
-    - disable the kernel log component of sysklogd/rsyslog/etc.,
-      otherwise they will fail to read the log, and at least rsyslog
-      will fill the filesystem with error messages
-
   TODO:
     - move hardcoded parameters into hypervisor parameters, once we
       have the container-parameter support
@@ -60,10 +52,6 @@ class LXCHypervisor(hv_base.BaseHypervisor):
       indication, and when failing it can leave network interfaces
       around, and future successful startups will list the instance
       twice
-    - shutdown sequence of containers leaves the init 'dead', and the
-      container effectively stopped, but LXC still believes the
-      container to be running; need to investigate using the
-      notify_on_release and release_agent feature of cgroups
 
   """
   _ROOT_DIR = pathutils.RUN_DIR + "/lxc"
@@ -146,7 +134,7 @@ class LXCHypervisor(hv_base.BaseHypervisor):
     """
     cgroup = cls._GetCgroupMountPoint()
     try:
-      cpus = utils.ReadFile(utils.PathJoin(cgroup,
+      cpus = utils.ReadFile(utils.PathJoin(cgroup, 'lxc',
                                            instance_name,
                                            "cpuset.cpus"))
     except EnvironmentError, err:
@@ -159,10 +147,7 @@ class LXCHypervisor(hv_base.BaseHypervisor):
     """Get the list of running instances.
 
     """
-    result = utils.RunCmd(["lxc-ls"])
-    if result.failed:
-      raise errors.HypervisorError("Running lxc-ls failed: %s" % result.output)
-    return result.stdout.splitlines()
+    return [ iinfo[0] for iinfo in self.GetAllInstancesInfo() ]
 
   def GetInstanceInfo(self, instance_name):
     """Get instance properties.
@@ -175,13 +160,13 @@ class LXCHypervisor(hv_base.BaseHypervisor):
     """
     # TODO: read container info from the cgroup mountpoint
 
-    result = utils.RunCmd(["lxc-info", "-n", instance_name])
+    result = utils.RunCmd(["lxc-info", "-s", "-n", instance_name])
     if result.failed:
       raise errors.HypervisorError("Running lxc-info failed: %s" %
                                    result.output)
     # lxc-info output examples:
-    # 'ganeti-lxc-test1' is STOPPED
-    # 'ganeti-lxc-test1' is RUNNING
+    # 'state: STOPPED
+    # 'state: RUNNING
     _, state = result.stdout.rsplit(None, 1)
     if state != "RUNNING":
       return None
@@ -196,8 +181,13 @@ class LXCHypervisor(hv_base.BaseHypervisor):
 
     """
     data = []
-    for name in self.ListInstances():
-      data.append(self.GetInstanceInfo(name))
+    for name in os.listdir(self._ROOT_DIR):
+      try:
+        info = self.GetInstanceInfo(name)
+      except errors.HypervisorError:
+        continue
+      if info:
+        data.append(info)
     return data
 
   def _CreateConfigFile(self, instance, root_dir):
@@ -270,7 +260,7 @@ class LXCHypervisor(hv_base.BaseHypervisor):
   def StartInstance(self, instance, block_devices, startup_paused):
     """Start an instance.
 
-    For LCX, we try to mount the block device and execute 'lxc-start'.
+    For LXC, we try to mount the block device and execute 'lxc-start'.
     We use volatile containers.
 
     """
@@ -338,6 +328,9 @@ class LXCHypervisor(hv_base.BaseHypervisor):
         logging.warning("Error while doing lxc-stop for %s: %s", name,
                         result.output)
 
+    if not os.path.ismount(root_dir):
+        return
+
     for mpath in self._GetMountSubdirs(root_dir):
       result = utils.RunCmd(["umount", mpath])
       if result.failed: