1 files changed, 135 insertions, 14 deletions
diff --git a/cloudinit/util.py b/cloudinit/util.py
index e6489648..c37f0316 100644
--- a/cloudinit/util.py
+++ b/cloudinit/util.py
@@ -32,6 +32,7 @@ import re
 import socket
 import sys
 import time
+import tempfile
 import traceback
 import urlparse
 
@@ -515,30 +516,70 @@ def dos2unix(string):
     return(string.replace('\r\n', '\n'))
 
 
-def islxc():
-    # is this host running lxc?
+def is_container():
+    # is this code running in a container of some sort
+
+    for helper in ('running-in-container', 'lxc-is-container'):
+        try:
+            # try to run a helper program. if it returns true
+            # then we're inside a container. otherwise, no
+            sp = subprocess.Popen(helper, stdout=subprocess.PIPE,
+                                  stderr=subprocess.PIPE)
+            sp.communicate(None)
+            return(sp.returncode == 0)
+        except OSError as e:
+            if e.errno != errno.ENOENT:
+                raise
+
+    # this code is largely from the logic in
+    # ubuntu's /etc/init/container-detect.conf
     try:
-        with open("/proc/1/cgroup") as f:
-            if f.read() == "/":
-                return True
+        # Detect old-style libvirt
+        # Detect OpenVZ containers
+        pid1env = get_proc_env(1)
+        if "container" in pid1env:
+            return True
+
+        if "LIBVIRT_LXC_UUID" in pid1env:
+            return True
+
     except IOError as e:
         if e.errno != errno.ENOENT:
-            raise
+            pass
+
+    # Detect OpenVZ containers
+    if os.path.isdir("/proc/vz") and not os.path.isdir("/proc/bc"):
+        return True
 
     try:
-        # try to run a program named 'lxc-is-container'. if it returns true,
-        # then we're inside a container. otherwise, no
-        sp = subprocess.Popen(['lxc-is-container'], stdout=subprocess.PIPE,
-                              stderr=subprocess.PIPE)
-        sp.communicate(None)
-        return(sp.returncode == 0)
-    except OSError as e:
+        # Detect Vserver containers
+        with open("/proc/self/status") as fp:
+            lines = fp.read().splitlines()
+            for line in lines:
+                if line.startswith("VxID:"):
+                    (_key, val) = line.strip().split(":", 1)
+                    if val != "0":
+                        return True
+    except IOError as e:
         if e.errno != errno.ENOENT:
-            raise
+            pass
 
     return False
 
 
+def get_proc_env(pid):
+    # return the environment in a dict that a given process id was started with
+    env = {}
+    with open("/proc/%s/environ" % pid) as fp:
+        toks = fp.read().split("\0")
+        for tok in toks:
+            if tok == "":
+                continue
+            (name, val) = tok.split("=", 1)
+            env[name] = val
+    return env
+
+
 def get_hostname_fqdn(cfg, cloud):
     # return the hostname and fqdn from 'cfg'.  If not found in cfg,
     # then fall back to data from cloud
@@ -630,3 +671,83 @@ def close_stdin():
         return
     with open(os.devnull) as fp:
         os.dup2(fp.fileno(), sys.stdin.fileno())
+
+
+def find_devs_with(criteria):
+    """
+    find devices matching given criteria (via blkid)
+    criteria can be *one* of:
+      TYPE=<filesystem>
+      LABEL=<label>
+      UUID=<uuid>
+    """
+    try:
+        (out, _err) = subp(['blkid', '-t%s' % criteria, '-odevice'])
+    except subprocess.CalledProcessError:
+        return([])
+    return(str(out).splitlines())
+
+
+class mountFailedError(Exception):
+    pass
+
+
+def mount_callback_umount(device, callback, data=None):
+    """
+    mount the device, call method 'callback' passing the directory
+    in which it was mounted, then unmount.  Return whatever 'callback'
+    returned.  If data != None, also pass data to callback.
+    """
+
+    def _cleanup(umount, tmpd):
+        if umount:
+            try:
+                subp(["umount", '-l', umount])
+            except subprocess.CalledProcessError:
+                raise
+        if tmpd:
+            os.rmdir(tmpd)
+
+    # go through mounts to see if it was already mounted
+    fp = open("/proc/mounts")
+    mounts = fp.readlines()
+    fp.close()
+
+    tmpd = None
+
+    mounted = {}
+    for mpline in mounts:
+        (dev, mp, fstype, _opts, _freq, _passno) = mpline.split()
+        mp = mp.replace("\\040", " ")
+        mounted[dev] = (dev, fstype, mp, False)
+
+    umount = False
+    if device in mounted:
+        mountpoint = "%s/" % mounted[device][2]
+    else:
+        tmpd = tempfile.mkdtemp()
+
+        mountcmd = ["mount", "-o", "ro", device, tmpd]
+
+        try:
+            (_out, _err) = subp(mountcmd)
+            umount = tmpd
+        except subprocess.CalledProcessError as exc:
+            _cleanup(umount, tmpd)
+            raise mountFailedError(exc.output[1])
+
+        mountpoint = "%s/" % tmpd
+
+    try:
+        if data == None:
+            ret = callback(mountpoint)
+        else:
+            ret = callback(mountpoint, data)
+
+    except Exception as exc:
+        _cleanup(umount, tmpd)
+        raise exc
+
+    _cleanup(umount, tmpd)
+
+    return(ret)