X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=tools.py;h=99e6dac63968aa2cac74179b695239eb2fd0619a;hb=refs%2Fheads%2Fdevel;hp=49441bda94a42af81f0e922565d97f37dc826911;hpb=2f100cd2a78a0f91022bc4a895007975181cf353;p=nodemanager.git

diff --git a/tools.py b/tools.py
index 49441bd..99e6dac 100644
--- a/tools.py
+++ b/tools.py
@@ -1,18 +1,45 @@
+# $Id$
+# $URL$
+
 """A few things that didn't seem to fit anywhere else."""
 
-import cPickle
-import errno
-import os
+import os, os.path
 import pwd
 import tempfile
-import threading
 import fcntl
+import errno
+import threading
+import subprocess
 
 import logger
 
+PID_FILE = '/var/run/nodemanager.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
 
-PID_FILE = '/var/run/nm.pid'
+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
 
+####################
+# daemonizing
 def as_daemon_thread(run):
     """Call function <run> with no arguments in its own thread."""
     thr = threading.Thread(target=run)
@@ -33,11 +60,11 @@ 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)
     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)
+    crashlog = os.open('/var/log/nodemanager.daemon', os.O_RDWR | os.O_APPEND | os.O_CREAT, 0644)
     os.dup2(crashlog, 1)
     os.dup2(crashlog, 2)
 
@@ -57,12 +84,16 @@ def fork_as(su, function, *args):
         except:
             os.seteuid(os.getuid())  # undo su so we can write the log file
             os.setegid(os.getgid())
-            logger.log_exc()
+            logger.log_exc("tools: fork_as")
         os._exit(0)
     else: os.waitpid(child_pid, 0)
 
+####################
+# manage files
 def pid_file():
-    """We use a pid file to ensure that only one copy of NM is running at a given time.  If successful, this function will write a pid file containing the pid of the current process.  The return value is the pid of the other running process, or None otherwise."""
+    """We use a pid file to ensure that only one copy of NM is running at a given time.
+If successful, this function will write a pid file containing the pid of the current process.
+The return value is the pid of the other running process, or None otherwise."""
     other_pid = None
     if os.access(PID_FILE, os.F_OK):  # check for a pid file
         handle = open(PID_FILE)  # pid file exists, read it
@@ -91,9 +122,65 @@ def write_temp_file(do_write, mode=None, uidgid=None):
     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
+
+_root_context_arch=None
+def root_context_arch():
+    global _root_context_arch
+    if not _root_context_arch:
+        sp=subprocess.Popen(["uname","-i"],stdout=subprocess.PIPE)
+        (_root_context_arch,_)=sp.communicate()
+        _root_context_arch=_root_context_arch.strip()
+    return _root_context_arch
+
 
+####################
 class NMLock:
     def __init__(self, file):
+        logger.log("tools: 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
@@ -101,6 +188,8 @@ class NMLock:
     def __del__(self):
         os.close(self.fd)
     def acquire(self):
-        fcntl.lockf(self.fd, fcntl.LOCK_EX)
+        logger.log("tools: Lock acquired.", 2)
+        fcntl.lockf(self.fd, fcntl.LOCK_SH)
     def release(self):
+        logger.log("tools: Lock released.", 2)
         fcntl.lockf(self.fd, fcntl.LOCK_UN)