Next generation of zinit, which still needs a number of features,

like a more thought-out logging mechanism (which Zope needs too,
Waaa) and standard "well-behaved deamon" behavior.

lib/python/zdeamon.py

+#!/usr/local/bin/python1.5.1
+##############################################################################
+# 
+# Zope Public License (ZPL) Version 1.0
+# -------------------------------------
+# 
+# Copyright (c) Digital Creations.  All rights reserved.
+# 
+# This license has been certified as Open Source(tm).
+# 
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+# 
+# 1. Redistributions in source code must retain the above copyright
+#    notice, this list of conditions, and the following disclaimer.
+# 
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions, and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 
+# 3. Digital Creations requests that attribution be given to Zope
+#    in any manner possible. Zope includes a "Powered by Zope"
+#    button that is installed by default. While it is not a license
+#    violation to remove this button, it is requested that the
+#    attribution remain. A significant investment has been put
+#    into Zope, and this effort will continue if the Zope community
+#    continues to grow. This is one way to assure that growth.
+# 
+# 4. All advertising materials and documentation mentioning
+#    features derived from or use of this software must display
+#    the following acknowledgement:
+# 
+#      "This product includes software developed by Digital Creations
+#      for use in the Z Object Publishing Environment
+#      (http://www.zope.org/)."
+# 
+#    In the event that the product being advertised includes an
+#    intact Zope distribution (with copyright and license included)
+#    then this clause is waived.
+# 
+# 5. Names associated with Zope or Digital Creations must not be used to
+#    endorse or promote products derived from this software without
+#    prior written permission from Digital Creations.
+# 
+# 6. Modified redistributions of any form whatsoever must retain
+#    the following acknowledgment:
+# 
+#      "This product includes software developed by Digital Creations
+#      for use in the Z Object Publishing Environment
+#      (http://www.zope.org/)."
+# 
+#    Intact (re-)distributions of any official Zope release do not
+#    require an external acknowledgement.
+# 
+# 7. Modifications are encouraged but must be packaged separately as
+#    patches to official Zope releases.  Distributions that do not
+#    clearly separate the patches from the original work must be clearly
+#    labeled as unofficial distributions.  Modifications which do not
+#    carry the name Zope may be packaged in any form, as long as they
+#    conform to all of the clauses above.
+# 
+# 
+# Disclaimer
+# 
+#   THIS SOFTWARE IS PROVIDED BY DIGITAL CREATIONS ``AS IS'' AND ANY
+#   EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+#   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+#   PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL DIGITAL CREATIONS OR ITS
+#   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+#   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+#   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+#   USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+#   ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+#   OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+#   OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+#   SUCH DAMAGE.
+# 
+# 
+# This software consists of contributions made by Digital Creations and
+# many individuals on behalf of Digital Creations.  Specific
+# attributions are listed in the accompanying credits file.
+# 
+##############################################################################
+"""
+
+zinit, slightly smarter server manager and ZServer startup script.
+
+  zinit will:
+
+    - Fork a parent and a child
+
+    - restart the child if it dies
+
+    - write a pid file so you can kill (the parent)
+
+    - reports the childs pid to stdout so you can kill that too
+
+TODO
+
+  - Have the parent reap the children when it dies
+
+  - etc.
+
+"""
+
+import os, sys, time, signal
+
+pyth = sys.executable
+
+class KidDiedOnMeError:
+    pass
+
+class ExecError:
+    pass
+
+class ForkError:
+    pass
+
+FORK_ATTEMPTS = 2
+
+# This is the number of seconds between the parent pulsing the child.
+# Set to 0 to deactivate pulsing.
+
+BEAT_DELAY = 0
+VERBOSE = 1
+
+# If you want the parent to 'pulse' Zope every 'BEAT_DELAY' seconds,
+# put the URL to the method you want to call here.  This can be any
+# methodish object that can be called through the web.  Format is:
+#
+# activities = (("http://x/method", "username", "password"),)
+#
+# username and password may be None if the method does not require
+# authentication. 
+
+# activities = (('http://localhost:9222/Heart/heart', 'michel', '123'),
+#               )
+
+
+def pstamp(message):
+    print "zinit: %s: %s" % (time.ctime(time.time()), message)
+
+def heartbeat():
+    print 'tha-thump'
+    if activities:
+        for a in activities:
+            try:
+                result = ZPublisher.Client.call(a[0], a[1], a[2])
+            except:
+                pstamp('activity %s failed!' % a[0])
+                return
+
+            if result and VERBOSE:
+                pstamp('activity %s returned: %s' % (a[0], result))
+
+
+def forkit(attempts = FORK_ATTEMPTS):
+    while attempts:
+        # if at first you don't succeed...
+        attempts = attempts + 1
+        try:
+            pid = os.fork()
+        except os.error:
+            pstamp('Houston, the fork failed')
+            time.sleep(2)
+        else:
+            pstamp('Houston, we have forked')
+            return pid
+
+def run(argv, pidfile=''):
+    if os.environ.has_key('ZDEAMON_MANAGED'): return
+    os.environ['ZDEAMON_MANAGED']='TRUE'
+    while 1:
+        try:
+            pid = forkit()
+
+            if pid is None:
+                raise ForkError
+
+            elif pid:
+                # Parent 
+                pstamp(('Hi, I just forked off a kid: %s' % pid))
+                # here we want the pid of the parent
+                if pidfile:
+                    pf = open(pidfile, 'w+')
+                    pf.write(("%s" % os.getpid()))
+                    pf.close()
+
+                while 1:
+                    if not BEAT_DELAY:
+                        p,s = os.waitpid(pid, 0)
+                    else:
+                        p,s = os.waitpid(pid, os.WNOHANG)
+                        if not p:
+                            time.sleep(BEAT_DELAY)
+                            heartbeat()
+                            continue
+                    if s:
+                        pstamp(('Aiieee! %s exited with error code: %s' 
+                                % (p, s)))
+                    else:
+                        raise ForkError
+                        pstamp(('The kid, %s, died on me.' % pid))
+
+                    raise KidDiedOnMeError
+
+            else:
+                # Child
+                os.execv(pyth, (pyth,)+tuple(argv))
+                
+
+        except ExecError:
+            sys.exit()
+        except ForkError:
+            sys.exit()
+        except KidDiedOnMeError:
+            pass
+
+def main():
+    argv=sys.argv[1:]
+    if argv and argv[0][:2]=='-p':
+        pidf=argv[0][2:]
+        del argv[0]
+    else:
+        pidf=''
+
+    if not argv:
+        print __doc__ % vars()
+        print
+        print 'Error: no script given'
+            
+    run(argv, pidf)
+    
+
+if __name__ == '__main__': main()
+
+
+
+
+
+
+