1 """A few things that didn't seem to fit anywhere else."""
16 PID_FILE = '/var/run/nodemanager.pid'
20 interface = get_if_from_hwaddr(get_hwaddr_from_plnode())
21 if not interface: interface = "eth0"
24 def get_hwaddr_from_plnode():
26 for line in open("/usr/boot/plnode.txt", 'r').readlines():
27 if line.startswith("NET_DEVICE"):
28 return line.split("=")[1].strip().strip('"')
33 def get_if_from_hwaddr(hwaddr):
37 dev_hwaddr = sioc.gifhwaddr(dev)
38 if dev_hwaddr == hwaddr: return dev
43 def as_daemon_thread(run):
44 """Call function <run> with no arguments in its own thread."""
45 thr = threading.Thread(target=run)
49 def close_nonstandard_fds():
50 """Close all open file descriptors other than 0, 1, and 2."""
52 for fd in range(3, os.sysconf(_SC_OPEN_MAX)):
54 except OSError: pass # most likely an fd that isn't open
56 # after http://www.erlenstar.demon.co.uk/unix/faq_2.html
58 """Daemonize the current process."""
59 if os.fork() != 0: os._exit(0)
61 if os.fork() != 0: os._exit(0)
64 devnull = os.open(os.devnull, os.O_RDWR)
66 # xxx fixme - this is just to make sure that nothing gets stupidly lost - should use devnull
67 crashlog = os.open('/var/log/nodemanager.daemon', os.O_RDWR | os.O_APPEND | os.O_CREAT, 0644)
71 def fork_as(su, function, *args):
72 """fork(), cd / to avoid keeping unused directories open, close all nonstandard file descriptors (to avoid capturing open sockets), fork() again (to avoid zombies) and call <function> with arguments <args> in the grandchild process. If <su> is not None, set our group and user ids appropriately in the child process."""
77 close_nonstandard_fds()
79 pw_ent = pwd.getpwnam(su)
83 if child_pid == 0: function(*args)
85 os.seteuid(os.getuid()) # undo su so we can write the log file
86 os.setegid(os.getgid())
87 logger.log_exc("tools: fork_as")
89 else: os.waitpid(child_pid, 0)
94 """We use a pid file to ensure that only one copy of NM is running at a given time.
95 If successful, this function will write a pid file containing the pid of the current process.
96 The return value is the pid of the other running process, or None otherwise."""
98 if os.access(PID_FILE, os.F_OK): # check for a pid file
99 handle = open(PID_FILE) # pid file exists, read it
100 other_pid = int(handle.read())
102 # check for a process with that pid by sending signal 0
103 try: os.kill(other_pid, 0)
105 if e.errno == errno.ESRCH: other_pid = None # doesn't exist
106 else: raise # who knows
107 if other_pid == None:
108 # write a new pid file
109 write_file(PID_FILE, lambda f: f.write(str(os.getpid())))
112 def write_file(filename, do_write, **kw_args):
113 """Write file <filename> atomically by opening a temporary file, using <do_write> to write that file, and then renaming the temporary file."""
114 shutil.move(write_temp_file(do_write, **kw_args), filename)
116 def write_temp_file(do_write, mode=None, uidgid=None):
117 fd, temporary_filename = tempfile.mkstemp()
118 if mode: os.chmod(temporary_filename, mode)
119 if uidgid: os.chown(temporary_filename, *uidgid)
120 f = os.fdopen(fd, 'w')
123 return temporary_filename
125 # replace a target file with a new contents - checks for changes
126 # can handle chmod if requested
127 # can also remove resulting file if contents are void, if requested
128 # performs atomically:
129 # writes in a tmp file, which is then renamed (from sliverauth originally)
130 # returns True if a change occurred, or the file is deleted
131 def replace_file_with_string (target, new_contents, chmod=None, remove_if_empty=False):
133 current=file(target).read()
136 if current==new_contents:
137 # if turns out to be an empty string, and remove_if_empty is set,
138 # then make sure to trash the file if it exists
139 if remove_if_empty and not new_contents and os.path.isfile(target):
140 logger.verbose("tools.replace_file_with_string: removing file %s"%target)
141 try: os.unlink(target)
144 # overwrite target file: create a temp in the same directory
145 path=os.path.dirname(target) or '.'
146 fd, name = tempfile.mkstemp('','repl',path)
147 os.write(fd,new_contents)
149 if os.path.exists(target):
151 shutil.move(name,target)
152 if chmod: os.chmod(target,chmod)
157 # utilities functions to get (cached) information from the node
159 # get node_id from /etc/planetlab/node_id and cache it
165 _node_id=int(file("/etc/planetlab/node_id").read())
170 _root_context_arch=None
171 def root_context_arch():
172 global _root_context_arch
173 if not _root_context_arch:
174 sp=subprocess.Popen(["uname","-i"],stdout=subprocess.PIPE)
175 (_root_context_arch,_)=sp.communicate()
176 _root_context_arch=_root_context_arch.strip()
177 return _root_context_arch
182 def __init__(self, file):
183 logger.log("tools: Lock %s initialized." % file, 2)
184 self.fd = os.open(file, os.O_RDWR|os.O_CREAT, 0600)
185 flags = fcntl.fcntl(self.fd, fcntl.F_GETFD)
186 flags |= fcntl.FD_CLOEXEC
187 fcntl.fcntl(self.fd, fcntl.F_SETFD, flags)
191 logger.log("tools: Lock acquired.", 2)
192 fcntl.lockf(self.fd, fcntl.LOCK_SH)
194 logger.log("tools: Lock released.", 2)
195 fcntl.lockf(self.fd, fcntl.LOCK_UN)
198 # Utilities for getting the IP address of a LXC/Openvswitch slice. Do this by
199 # running ifconfig inside of the slice's context.
201 def get_sliver_process(slice_name, process_cmdline):
202 """ Utility function to find a process inside of an LXC sliver. Returns
203 (cgroup_fn, pid). cgroup_fn is the filename of the cgroup file for
204 the process, for example /proc/2592/cgroup. Pid is the process id of
205 the process. If the process is not found then (None, None) is returned.
208 cmd = 'grep %s /proc/*/cgroup | grep freezer'%slice_name
209 output = os.popen(cmd).readlines()
211 # the slice couldn't be found
212 logger.log("get_sliver_process: couldn't find slice %s" % slice_name)
220 path = l.split(':')[0]
221 comp = l.rsplit(':')[-1]
222 slice_name_check = comp.rsplit('/')[-1]
224 if (slice_name_check == slice_name):
226 pid = slice_path.split('/')[2]
227 cmdline = open('/proc/%s/cmdline'%pid).read().rstrip('\n\x00')
228 if (cmdline == process_cmdline):
229 cgroup_fn = slice_path
234 if (not cgroup_fn) or (not pid):
235 logger.log("get_sliver_process: process %s not running in slice %s" % (process_cmdline, slice_name))
238 return (cgroup_fn, pid)
240 def get_sliver_ifconfig(slice_name, device="eth0"):
241 """ return the output of "ifconfig" run from inside the sliver.
243 side effects: adds "/usr/sbin" to sys.path
246 # See if setns is installed. If it's not then we're probably not running
248 if not os.path.exists("/usr/sbin/setns.so"):
251 # setns is part of lxcsu and is installed to /usr/sbin
252 if not "/usr/sbin" in sys.path:
253 sys.path.append("/usr/sbin")
256 (cgroup_fn, pid) = get_sliver_process(slice_name, "/sbin/init")
257 if (not cgroup_fn) or (not pid):
260 path = '/proc/%s/ns/net'%pid
264 setns.chcontext(path)
266 args = ["/sbin/ifconfig", device]
267 sub = subprocess.Popen(args, stderr = subprocess.PIPE, stdout = subprocess.PIPE)
270 if (sub.returncode != 0):
271 logger.log("get_slice_ifconfig: error in ifconfig: %s" % sub.stderr.read())
273 result = sub.stdout.read()
275 setns.chcontext("/proc/1/ns/net")
279 def get_sliver_ip(slice_name):
280 ifconfig = get_sliver_ifconfig(slice_name)
284 for line in ifconfig.split("\n"):
285 if "inet addr:" in line:
286 # example: ' inet addr:192.168.122.189 Bcast:192.168.122.255 Mask:255.255.255.0'
287 parts = line.strip().split()
288 if len(parts)>=2 and parts[1].startswith("addr:"):
289 return parts[1].split(":")[1]
293 ### this returns the kind of virtualization on the node
294 # either 'vs' or 'lxc'
295 # also caches it in /etc/planetlab/virt for next calls
296 # could be promoted to core nm if need be
297 virt_stamp="/etc/planetlab/virt"
298 def get_node_virt ():
300 return file(virt_stamp).read().strip()
303 logger.log("Computing virt..")
305 if subprocess.call ([ 'vserver', '--help' ]) ==0: virt='vs'
309 with file(virt_stamp,"w") as f:
313 ### this return True or False to indicate that systemctl is present on that box
314 # cache result in memory as _has_systemctl
316 def has_systemctl ():
317 if _has_systemctl is None:
318 _has_systemctl = (subprocess.call([ 'systemctl', '--help' ]) == 0)
319 return _has_systemctl
321 # how to run a command in a slice
322 # now this is a painful matter
323 # the problem is with capsh that forces a bash command to be injected in its exec'ed command
324 # so because lxcsu uses capsh, you cannot exec anything else than bash
325 # bottom line is, what actually needs to be called is
326 # vs: vserver exec slicename command and its arguments
327 # lxc: lxcsu slicename "command and its arguments"
328 # which, OK, is no big deal as long as the command is simple enough,
329 # but do not stretch it with arguments that have spaces or need quoting as that will become a nightmare
330 def command_in_slice (slicename, argv):
333 return [ 'vserver', slicename, 'exec', ] + argv
335 # wrap up argv in a single string for -c
336 return [ 'lxcsu', slicename, ] + [ " ".join(argv) ]
337 logger.log("command_in_slice: WARNING: could not find a valid virt")
342 def handler (signum, frame):
343 logger.log("Received signal %d - exiting"%signum)
345 signal.signal(signal.SIGHUP,handler)
346 signal.signal(signal.SIGQUIT,handler)
347 signal.signal(signal.SIGINT,handler)
348 signal.signal(signal.SIGTERM,handler)