add util.log_time helper

The reason for this is that more and more things I was wanting to be able to
see how long they took.  This puts that time logic into a single place.  It
also supports (by default) reading from /proc/uptime as the timing mechanism.

While that is almost certainly slower than time.time(), it does give 
millisecond granularity and is not affected by 'ntpdate' having
run in between the two events.

6 files changed, 55 insertions, 16 deletions

diff --git a/ChangeLog b/ChangeLog
index a255d24a..68d03376 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -11,6 +11,9 @@
  - always finalize handlers even if processing failed (LP: #1203368)
  - support merging into cloud-config via jsonp. (LP: #1200476)
  - add datasource 'SmartOS' for Joyent Cloud.  Adds a dependency on serial.
+ - add 'log_time' helper to util for timing how long things take
+   which also reads from uptime. uptime is useful as clock may change during
+   boot due to ntp.
 0.7.2:
  - add a debian watch file
  - add 'sudo' entry to ubuntu's default user (LP: #1080717)
diff --git a/bin/cloud-init b/bin/cloud-init
index c5a5b949..bd9ddc04 100755
--- a/bin/cloud-init
+++ b/bin/cloud-init
@@ -502,7 +502,10 @@ def main():
     signal_handler.attach_handlers()
 
     (name, functor) = args.action
-    return functor(name, args)
+
+    return util.log_time(logfunc=LOG.debug,
+                         msg="cloud-init mode '%s'" % name, uptime=True,
+                         func=functor, args=(name, args))
 
 
 if __name__ == '__main__':
diff --git a/cloudinit/config/cc_growpart.py b/cloudinit/config/cc_growpart.py
index 4f8c8f80..ba6c58af 100644
--- a/cloudinit/config/cc_growpart.py
+++ b/cloudinit/config/cc_growpart.py
@@ -264,7 +264,8 @@ def handle(_name, cfg, _cloud, log, _args):
             raise e
         return
 
-    resized = resize_devices(resizer, devices)
+    resized = util.log_time(logfunc=log.debug, msg="resize_devices",
+                            func=resize_devices, args=(resizer, devices))
     for (entry, action, msg) in resized:
         if action == RESIZE.CHANGED:
             log.info("'%s' resized: %s" % (entry, msg))
diff --git a/cloudinit/config/cc_resizefs.py b/cloudinit/config/cc_resizefs.py
index b4ee16b2..56040fdd 100644
--- a/cloudinit/config/cc_resizefs.py
+++ b/cloudinit/config/cc_resizefs.py
@@ -21,7 +21,6 @@
 import errno
 import os
 import stat
-import time
 
 from cloudinit.settings import PER_ALWAYS
 from cloudinit import util
@@ -120,9 +119,12 @@ def handle(name, cfg, _cloud, log, args):
     if resize_root == NOBLOCK:
         # Fork to a child that will run
         # the resize command
-        util.fork_cb(do_resize, resize_cmd, log)
+        util.fork_cb(
+            util.log_time(logfunc=log.debug, msg="backgrounded Resizing",
+                func=do_resize, args=(resize_cmd, log)))
     else:
-        do_resize(resize_cmd, log)
+        util.log_time(logfunc=log.debug, msg="Resizing",
+            func=do_resize, args=(resize_cmd, log))
 
     action = 'Resized'
     if resize_root == NOBLOCK:
@@ -132,13 +134,10 @@ def handle(name, cfg, _cloud, log, args):
 
 
 def do_resize(resize_cmd, log):
-    start = time.time()
     try:
         util.subp(resize_cmd)
     except util.ProcessExecutionError:
         util.logexc(log, "Failed to resize filesystem (cmd=%s)", resize_cmd)
         raise
-    tot_time = time.time() - start
-    log.debug("Resizing took %.3f seconds", tot_time)
     # TODO(harlowja): Should we add a fsck check after this to make
     # sure we didn't corrupt anything?
diff --git a/cloudinit/sources/DataSourceAzure.py b/cloudinit/sources/DataSourceAzure.py
index 2f28702e..f906b8fa 100644
--- a/cloudinit/sources/DataSourceAzure.py
+++ b/cloudinit/sources/DataSourceAzure.py
@@ -138,13 +138,11 @@ class DataSourceAzureNet(sources.DataSource):
             bname = pk['fingerprint'] + ".crt"
             fp_files += [os.path.join(mycfg['data_dir'], bname)]
 
-        start = time.time()
-        missing = wait_for_files(wait_for + fp_files)
+        missing = util.log_time(logfunc=LOG.debug, msg="waiting for files",
+                                func=wait_for_files,
+                                args=(wait_for + fp_files,))
         if len(missing):
             LOG.warn("Did not find files, but going on: %s", missing)
-        else:
-            LOG.debug("waited %.3f seconds for %d files to appear",
-                      time.time() - start, len(wait_for))
 
         if shcfgxml in missing:
             LOG.warn("SharedConfig.xml missing, using static instance-id")
@@ -206,11 +204,11 @@ def apply_hostname_bounce(hostname, policy, interface, command,
         command = BOUNCE_COMMAND
 
     LOG.debug("pubhname: publishing hostname [%s]", msg)
-    start = time.time()
     shell = not isinstance(command, (list, tuple))
     # capture=False, see comments in bug 1202758 and bug 1206164.
-    (output, err) = util.subp(command, shell=shell, capture=False, env=env)
-    LOG.debug("publishing hostname took %.3f seconds", time.time() - start)
+    util.log_time(logfunc=LOG.debug, msg="publishing hostname",
+        func=util.subp, kwargs={'command': command, 'shell': shell,
+                                'capture': False, 'env': env})
 
 
 def crtfile_to_pubkey(fname):
diff --git a/cloudinit/util.py b/cloudinit/util.py
index 8542fe27..b0eb56e6 100644
--- a/cloudinit/util.py
+++ b/cloudinit/util.py
@@ -1770,3 +1770,38 @@ def which(program):
                 return exe_file
 
     return None
+
+
+def log_time(logfunc, msg, func, args=None, kwargs=None, get_uptime=True):
+    if args is None:
+        args = []
+    if kwargs is None:
+        kwargs = {}
+
+    start = time.time()
+
+    ustart = None
+    if get_uptime:
+        try:
+            ustart = float(uptime())
+        except ValueError:
+            pass
+
+    try:
+        ret = func(*args, **kwargs)
+    finally:
+        delta = time.time() - start
+        if ustart is not None:
+            try:
+                udelta = float(uptime()) - ustart
+            except ValueError:
+                udelta = "N/A"
+
+        tmsg = " took %0.3f seconds" % delta
+        if get_uptime:
+            tmsg += "(%0.2f)" % udelta
+        try:
+            logfunc(msg + tmsg)
+        except:
+            pass
+    return ret