refactored out middleware, now it's a decorator on service.api

1 files changed, 92 insertions, 54 deletions

diff --git a/nova/utils.py b/nova/utils.py
index 0cf91e0cc..24b8da9ea 100644
--- a/nova/utils.py
+++ b/nova/utils.py
@@ -23,10 +23,14 @@ System-level utilities and helper functions.
 
 import base64
 import datetime
+import functools
 import inspect
 import json
+import lockfile
+import netaddr
 import os
 import random
+import re
 import socket
 import string
 import struct
@@ -34,20 +38,20 @@ import sys
 import time
 import types
 from xml.sax import saxutils
-import re
-import netaddr
 
 from eventlet import event
 from eventlet import greenthread
 from eventlet.green import subprocess
-
+None
 from nova import exception
 from nova.exception import ProcessExecutionError
+from nova import flags
 from nova import log as logging
 
 
 LOG = logging.getLogger("nova.utils")
 TIME_FORMAT = "%Y-%m-%dT%H:%M:%SZ"
+FLAGS = flags.FLAGS
 
 
 def import_class(import_str):
@@ -125,40 +129,59 @@ def fetchfile(url, target):
 #    c.perform()
 #    c.close()
 #    fp.close()
-    execute("curl --fail %s -o %s" % (url, target))
-
-
-def execute(cmd, process_input=None, addl_env=None, check_exit_code=True):
-    LOG.debug(_("Running cmd (subprocess): %s"), cmd)
-    env = os.environ.copy()
-    if addl_env:
-        env.update(addl_env)
-    obj = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE,
-        stdout=subprocess.PIPE, stderr=subprocess.PIPE, env=env)
-    result = None
-    if process_input != None:
-        result = obj.communicate(process_input)
-    else:
-        result = obj.communicate()
-    obj.stdin.close()
-    if obj.returncode:
-        LOG.debug(_("Result was %s") % obj.returncode)
-        if check_exit_code and obj.returncode != 0:
-            (stdout, stderr) = result
-            raise ProcessExecutionError(exit_code=obj.returncode,
-                                        stdout=stdout,
-                                        stderr=stderr,
-                                        cmd=cmd)
-    # NOTE(termie): this appears to be necessary to let the subprocess call
-    #               clean something up in between calls, without it two
-    #               execute calls in a row hangs the second one
-    greenthread.sleep(0)
-    return result
+    execute("curl", "--fail", url, "-o", target)
+
+
+def execute(*cmd, **kwargs):
+    process_input = kwargs.get('process_input', None)
+    addl_env = kwargs.get('addl_env', None)
+    check_exit_code = kwargs.get('check_exit_code', 0)
+    stdin = kwargs.get('stdin', subprocess.PIPE)
+    stdout = kwargs.get('stdout', subprocess.PIPE)
+    stderr = kwargs.get('stderr', subprocess.PIPE)
+    attempts = kwargs.get('attempts', 1)
+    cmd = map(str, cmd)
+
+    while attempts > 0:
+        attempts -= 1
+        try:
+            LOG.debug(_("Running cmd (subprocess): %s"), ' '.join(cmd))
+            env = os.environ.copy()
+            if addl_env:
+                env.update(addl_env)
+            obj = subprocess.Popen(cmd, stdin=stdin,
+                    stdout=stdout, stderr=stderr, env=env)
+            result = None
+            if process_input != None:
+                result = obj.communicate(process_input)
+            else:
+                result = obj.communicate()
+            obj.stdin.close()
+            if obj.returncode:
+                LOG.debug(_("Result was %s") % obj.returncode)
+                if type(check_exit_code) == types.IntType \
+                        and obj.returncode != check_exit_code:
+                    (stdout, stderr) = result
+                    raise ProcessExecutionError(exit_code=obj.returncode,
+                                                stdout=stdout,
+                                                stderr=stderr,
+                                                cmd=' '.join(cmd))
+            # NOTE(termie): this appears to be necessary to let the subprocess
+            #               call clean something up in between calls, without
+            #               it two execute calls in a row hangs the second one
+            greenthread.sleep(0)
+            return result
+        except ProcessExecutionError:
+            if not attempts:
+                raise
+            else:
+                LOG.debug(_("%r failed. Retrying."), cmd)
+                greenthread.sleep(random.randint(20, 200) / 100.0)
 
 
 def ssh_execute(ssh, cmd, process_input=None,
                 addl_env=None, check_exit_code=True):
-    LOG.debug(_("Running cmd (SSH): %s"), cmd)
+    LOG.debug(_("Running cmd (SSH): %s"), ' '.join(cmd))
     if addl_env:
         raise exception.Error("Environment not supported over SSH")
 
@@ -187,7 +210,7 @@ def ssh_execute(ssh, cmd, process_input=None,
             raise exception.ProcessExecutionError(exit_code=exit_status,
                                                   stdout=stdout,
                                                   stderr=stderr,
-                                                  cmd=cmd)
+                                                  cmd=' '.join(cmd))
 
     return (stdout, stderr)
 
@@ -220,9 +243,9 @@ def debug(arg):
     return arg
 
 
-def runthis(prompt, cmd, check_exit_code=True):
-    LOG.debug(_("Running %s"), (cmd))
-    rv, err = execute(cmd, check_exit_code=check_exit_code)
+def runthis(prompt, *cmd, **kwargs):
+    LOG.debug(_("Running %s"), (" ".join(cmd)))
+    rv, err = execute(*cmd, **kwargs)
 
 
 def generate_uid(topic, size=8):
@@ -239,13 +262,25 @@ def generate_mac():
     return ':'.join(map(lambda x: "%02x" % x, mac))
 
 
-def generate_password(length=20):
-    """Generate a random sequence of letters and digits
-    to be used as a password. Note that this is not intended
-    to represent the ultimate in security.
+# Default symbols to use for passwords. Avoids visually confusing characters.
+# ~6 bits per symbol
+DEFAULT_PASSWORD_SYMBOLS = ("23456789"  # Removed: 0,1
+                            "ABCDEFGHJKLMNPQRSTUVWXYZ"  # Removed: I, O
+                            "abcdefghijkmnopqrstuvwxyz")  # Removed: l
+
+
+# ~5 bits per symbol
+EASIER_PASSWORD_SYMBOLS = ("23456789"  # Removed: 0, 1
+                           "ABCDEFGHJKLMNPQRSTUVWXYZ")  # Removed: I, O
+
+
+def generate_password(length=20, symbols=DEFAULT_PASSWORD_SYMBOLS):
+    """Generate a random password from the supplied symbols.
+
+    Believed to be reasonably secure (with a reasonable password length!)
     """
-    chrs = string.letters + string.digits
-    return "".join([random.choice(chrs) for i in xrange(length)])
+    r = random.SystemRandom()
+    return "".join([r.choice(symbols) for _i in xrange(length)])
 
 
 def last_octet(address):
@@ -254,7 +289,7 @@ def last_octet(address):
 
 def  get_my_linklocal(interface):
     try:
-        if_str = execute("ip -f inet6 -o addr show %s" % interface)
+        if_str = execute("ip", "-f", "inet6", "-o", "addr", "show", interface)
         condition = "\s+inet6\s+([0-9a-f:]+)/\d+\s+scope\s+link"
         links = [re.search(condition, x) for x in if_str[0].split('\n')]
         address = [w.group(1) for w in links if w is not None]
@@ -491,16 +526,19 @@ def loads(s):
     return json.loads(s)
 
 
-def ensure_b64_encoding(val):
-    """Safety method to ensure that values expected to be base64-encoded
-    actually are. If they are, the value is returned unchanged. Otherwise,
-    the encoded value is returned.
-    """
-    try:
-        dummy = base64.decode(val)
-        return val
-    except TypeError:
-        return base64.b64encode(val)
+def synchronized(name):
+    def wrap(f):
+        @functools.wraps(f)
+        def inner(*args, **kwargs):
+            LOG.debug(_("Attempting to grab %(lock)s for method "
+                        "%(method)s..." % {"lock": name,
+                                           "method": f.__name__}))
+            lock = lockfile.FileLock(os.path.join(FLAGS.lock_path,
+                                                  'nova-%s.lock' % name))
+            with lock:
+                return f(*args, **kwargs)
+        return inner
+    return wrap
 
 
 def get_from_path(items, path):