X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=tools.py;h=199d799def48edac009eae07c93f02133f922676;hb=refs%2Fheads%2F1.8;hp=994089e1bb69fe5ab4ee43b35106d09b4c4a43e2;hpb=28de48d05b66c4e7826d959a3ad48e87e8f13ee4;p=nodemanager.git

diff --git a/tools.py b/tools.py
index 994089e..199d799 100644
--- a/tools.py
+++ b/tools.py
@@ -6,12 +6,34 @@ import os
 import pwd
 import tempfile
 import threading
-
+import fcntl
+import commands
 import logger
 
-
 PID_FILE = '/var/run/nm.pid'
 
+def get_default_if():
+    interface = get_if_from_hwaddr(get_hwaddr_from_plnode())
+    if not interface: interface = "eth0"
+    return interface
+
+def get_hwaddr_from_plnode():
+    try:
+        for line in open("/usr/boot/plnode.txt", 'r').readlines():
+            if line.startswith("NET_DEVICE"):
+                return line.split("=")[1].strip().strip('"')
+    except:
+        pass
+    return None
+
+def get_if_from_hwaddr(hwaddr):
+    import sioc
+    devs = sioc.gifconf()
+    for dev in devs:
+        dev_hwaddr = sioc.gifhwaddr(dev)
+        if dev_hwaddr == hwaddr: return dev
+    return None
+
 def as_daemon_thread(run):
     """Call function <run> with no arguments in its own thread."""
     thr = threading.Thread(target=run)
@@ -32,9 +54,13 @@ def daemon():
     os.setsid()
     if os.fork() != 0: os._exit(0)
     os.chdir('/')
-    os.umask(0)
+    os.umask(0022)
     devnull = os.open(os.devnull, os.O_RDWR)
-    for fd in range(3): os.dup2(devnull, fd)
+    os.dup2(devnull, 0)
+    # xxx fixme - this is just to make sure that nothing gets stupidly lost - should use devnull
+    crashlog = os.open('/var/log/nm.daemon', os.O_RDWR | os.O_APPEND | os.O_CREAT, 0644)
+    os.dup2(crashlog, 1)
+    os.dup2(crashlog, 2)
 
 def fork_as(su, function, *args):
     """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."""
@@ -43,9 +69,10 @@ def fork_as(su, function, *args):
         try:
             os.chdir('/')
             close_nonstandard_fds()
-            pw_ent = pwd.getpwnam(su)
-            os.setegid(pw_ent[3])
-            os.seteuid(pw_ent[2])
+            if su:
+                pw_ent = pwd.getpwnam(su)
+                os.setegid(pw_ent[3])
+                os.seteuid(pw_ent[2])
             child_pid = os.fork()
             if child_pid == 0: function(*args)
         except:
@@ -84,3 +111,82 @@ def write_temp_file(do_write, mode=None, uidgid=None):
     try: do_write(f)
     finally: f.close()
     return temporary_filename
+
+# replace a target file with a new contents - checks for changes
+# can handle chmod if requested
+# can also remove resulting file if contents are void, if requested
+# performs atomically:
+#    writes in a tmp file, which is then renamed (from sliverauth originally)
+# returns True if a change occurred, or the file is deleted
+def replace_file_with_string (target, new_contents, chmod=None, remove_if_empty=False):
+    try:
+        current=file(target).read()
+    except:
+        current=""
+    if current==new_contents:
+        # if turns out to be an empty string, and remove_if_empty is set,
+        # then make sure to trash the file if it exists
+        if remove_if_empty and not new_contents and os.path.isfile(target):
+            logger.verbose("tools.replace_file_with_string: removing file %s"%target)
+            try: os.unlink(target)
+            finally: return True
+        return False
+    # overwrite target file: create a temp in the same directory
+    path=os.path.dirname(target) or '.'
+    fd, name = tempfile.mkstemp('','repl',path)
+    os.write(fd,new_contents)
+    os.close(fd)
+    if os.path.exists(target):
+        os.unlink(target)
+    os.rename(name,target)
+    if chmod: os.chmod(target,chmod)
+    return True
+
+# utilities functions to get (cached) information from the node
+
+# get node_id from /etc/planetlab/node_id and cache it
+_node_id=None
+def node_id():
+    global _node_id
+    if _node_id is None:
+        try:
+            _node_id=int(file("/etc/planetlab/node_id").read())
+        except:
+            _node_id=""
+    return _node_id
+
+# get slicefamily from /etc/planetlab/slicefamily and cache it
+# http://svn.planet-lab.org/wiki/SliceFamily
+_slicefamily=None
+def slicefamily():
+    global _slicefamily
+    if _slicefamily is None:
+        try:
+            _slicefamily=file("/etc/planetlab/slicefamily").read().strip()
+        except:
+            _slicefamily=""
+    return _slicefamily
+
+_root_context_arch=None
+def root_context_arch():
+    global _root_context_arch
+    if not _root_context_arch:
+        _root_context_arch=commands.getoutput("uname -i")
+    return _root_context_arch
+
+
+class NMLock:
+    def __init__(self, file):
+        logger.log("Lock %s initialized." % file, 2)
+        self.fd = os.open(file, os.O_RDWR|os.O_CREAT, 0600)
+        flags = fcntl.fcntl(self.fd, fcntl.F_GETFD)
+        flags |= fcntl.FD_CLOEXEC
+        fcntl.fcntl(self.fd, fcntl.F_SETFD, flags)
+    def __del__(self):
+        os.close(self.fd)
+    def acquire(self):
+        logger.log("Lock acquired.", 2)
+        fcntl.lockf(self.fd, fcntl.LOCK_SH)
+    def release(self):
+        logger.log("Lock released.", 2)
+        fcntl.lockf(self.fd, fcntl.LOCK_UN)