Merge lp:~cmiller/desktopcouch/getport-at-call-time into lp:desktopcouch

[Chad Miller]

Use subprocess.Popen and ourselves to the wait()ing, since subprocess.call() is buggy. There's still an EINTR bug in subprocess, though.

Occasionally stop couchdb in tests, so we exercise the automatic starting code. This will lead to spurious errors because of the aforementioned subprocess bug, but it's the right thing to do.

Abstract away some of the linuxisms and complain if we're run on an unsupported OS.

Fix a race condition in the process-testing code.

Replace the TestCase module with one that doesn't complain of dirty twisted reactors.

Add a means of stopping the desktop couchdb daemon.

Add an additional check that a found PID and process named correctly is indeed a process that this user started, so we don't try to talk to other local users' desktop couchdbs.

[Eric Casteleijn (thisfred)]

Tests run, code changes look good to me.

review: Approve

[Elliot Murphy (statik)]

yay, desperately needed cleanup.

review: Approve

=== modified file 'desktopcouch/__init__.py'
--- desktopcouch/__init__.py	2009-08-04 11:15:52 +0000
+++ desktopcouch/__init__.py	2009-08-13 12:12:22 +0000
@@ -21,52 +21,66 @@
 import errno
 import time
 
-def find_pid():
+def find_pid(start_if_not_running=True):
     # Work out whether CouchDB is running by looking at its pid file
-    from desktopcouch import local_files
-    pid = ''
-    try:
-        fp = open(local_files.FILE_PID)
-        pid = int(fp.read())
-        fp.close()
-    except IOError:
-        pass
+    def get_pid():
+        from desktopcouch import local_files
+        try:
+            pid_file = local_files.FILE_PID
+            with open(pid_file) as fp:
+                try:
+                    return int(fp.read())
+                except ValueError:
+                    return None
+        except IOError:
+            return None
 
-    if not is_couchdb(pid):
+    pid = get_pid()
+    if not process_is_couchdb(pid) and start_if_not_running:
         # pidfile is stale
         # start CouchDB by running the startup script
-        print "Desktop CouchDB is not running; starting it."
+        print "Desktop CouchDB is not running; starting it.",
         from desktopcouch import start_local_couchdb
         start_local_couchdb.start_couchdb()
-        time.sleep(2) # give the process a chance to start
+        for timeout in xrange(1000):
+            pid = get_pid()
+            if process_is_couchdb(pid):
+                break
+            print ".",
+            time.sleep(0.1)
 
-    # get the pid
-    try:
-        with open(local_files.FILE_PID) as pid_file:
-            pid = int(pid_file.read().strip())
-    except IOError, e:
-        if e.errno == ENOENT:
+        if process_is_couchdb(pid):
+            print " done."
+        else:
+            print " failed."
             raise RuntimeError("desktop-couch not started")
-        else:
-            raise
+
     return pid
 
-def is_couchdb(pid):
+def process_is_couchdb__linux(pid):
+    if not isinstance(pid, int):
+        return False
+
     proc_dir = "/proc/%s" % (pid,)
 
-    # check to make sure that the process still exists
-    if not os.path.isdir(proc_dir):
-        return False
-
-    # check to make sure it is actually a desktop-couch instance
-    with open(os.path.join(proc_dir, 'cmdline')) as cmd_file:
-        cmd = cmd_file.read()
-    if re.search('desktop-couch', cmd) is None:
+    try:
+        # check to make sure it is actually a desktop-couch instance
+        with open(os.path.join(proc_dir, 'cmdline')) as cmd_file:
+            cmd = cmd_file.read()
+        if '/desktop-couch' not in cmd:
+            return False
+
+        # make sure it's our process.
+        if not os.access(os.path.join(proc_dir, "mem"), os.W_OK):
+            return False
+
+    except IOError:
         return False
 
     return True
 
-def find_port(pid):
+
+def find_port__linux(pid):
     # Look in the CouchDB log to find the port number, someday.
     # Currently, we have to grovel around in /proc instead.
     # Oh, the huge manatee... (this replaced an lsof shell recipe
@@ -76,8 +90,12 @@
     
     # enumerate the process' file descriptors
     fd_dir = os.path.join(proc_dir, 'fd')
-    fd_paths = [os.readlink(os.path.join(fd_dir, fd))
-                for fd in os.listdir(fd_dir)]
+    try:
+        fd_paths = [os.readlink(os.path.join(fd_dir, fd))
+                    for fd in os.listdir(fd_dir)]
+    except OSError:
+        raise RuntimeError("Unable to find file descriptors in /proc")
+        
 
     # identify socket fds
     socket_matches = [re.match('socket:\\[([0-9]+)\\]', p) for p in fd_paths]
@@ -108,9 +126,24 @@
         for line in tcp_file:
             match = listening_regexp.match(line)
             if match is not None:
-                port = int(match.group(1), 16)
+                port = str(int(match.group(1), 16))
                 break
     if port is None:
         raise RuntimeError("Unable to find listening port")
 
-    return str(port)
+    return port
+
+
+
+import platform
+os_name = platform.system()
+try:
+    process_is_couchdb = {
+        "Linux":process_is_couchdb__linux
+        } [os_name]
+
+    find_port = {
+        "Linux":find_port__linux
+        } [os_name]
+except KeyError:
+    raise NotImplementedError("os %r is not yet supported" % (os_name,))

=== modified file 'desktopcouch/records/tests/test_field_registry.py'
--- desktopcouch/records/tests/test_field_registry.py	2009-07-08 17:48:11 +0000
+++ desktopcouch/records/tests/test_field_registry.py	2009-08-13 16:06:20 +0000
@@ -18,7 +18,7 @@
 """Test cases for field mapping"""
 
 import copy
-from twisted.trial.unittest import TestCase as TwistedTestCase
+from testtools import TestCase
 from desktopcouch.records.field_registry import (
     SimpleFieldMapping, MergeableListFieldMapping, Transformer)
 from desktopcouch.records.record import Record
@@ -53,7 +53,7 @@
         super(AppTransformer, self).__init__('Test App', field_registry)
 
 
-class TestFieldMapping(TwistedTestCase):
+class TestFieldMapping(TestCase):
     """Test Case for FieldMapping objects."""
 
     def setUp(self):
@@ -85,7 +85,7 @@
         self.assertEqual(None, mapping.getValue(record))
 
 
-class TestTransformer(TwistedTestCase):
+class TestTransformer(TestCase):
     """Test application specific transformer classes"""
 
     def setUp(self):

=== modified file 'desktopcouch/records/tests/test_record.py'
--- desktopcouch/records/tests/test_record.py	2009-07-08 17:48:11 +0000
+++ desktopcouch/records/tests/test_record.py	2009-08-13 16:06:20 +0000
@@ -18,7 +18,7 @@
 
 """Tests for the RecordDict object on which the Contacts API is built."""
 
-from twisted.trial.unittest import TestCase as TwistedTestCase
+from testtools import TestCase
 
 # pylint does not like relative imports from containing packages
 # pylint: disable-msg=F0401
@@ -26,7 +26,7 @@
     record_factory, IllegalKeyException, validate)
 
 
-class TestRecords(TwistedTestCase):
+class TestRecords(TestCase):
     """Test the record functionality"""
 
     def setUp(self):
@@ -180,7 +180,7 @@
           self.record.record_type)
 
 
-class TestRecordFactory(TwistedTestCase):
+class TestRecordFactory(TestCase):
     """Test Record/Mergeable List factories."""
 
     def setUp(self):

=== modified file 'desktopcouch/records/tests/test_server.py'
--- desktopcouch/records/tests/test_server.py	2009-08-10 21:32:52 +0000
+++ desktopcouch/records/tests/test_server.py	2009-08-12 14:26:40 +0000
@@ -19,7 +19,8 @@
 """testing database/contact.py module"""
 
 import testtools
-
+import random
+from desktopcouch.stop_local_couchdb import stop_couchdb
 from desktopcouch.records.server import CouchDatabase
 from desktopcouch.records.record import Record
 
@@ -49,6 +50,9 @@
     def tearDown(self):
         """tear down each test"""
         del self.database._server[self.dbname]
+        if random.choice([1,2,3,4]) == 3:  # don't harass it unnecessarily
+            print u"\u2620",  # death
+            stop_couchdb()
 
     def test_get_records_by_record_type_save_view(self):
         """Test getting mutliple records by type"""

=== modified file 'desktopcouch/start_local_couchdb.py' (properties changed: -x to +x)
--- desktopcouch/start_local_couchdb.py	2009-07-27 18:16:19 +0000
+++ desktopcouch/start_local_couchdb.py	2009-08-13 12:14:05 +0000
@@ -32,10 +32,12 @@
 """
 
 from __future__ import with_statement
-import os, subprocess, sys
+import os, sys
+import subprocess
 import desktopcouch
 from desktopcouch import local_files
 import xdg.BaseDirectory
+import errno
 import time
 
 def dump_ini(data, filename):
@@ -52,8 +54,6 @@
         fd.write("\n")
     fd.close()
 
-
-
 def create_ini_file():
     """Write CouchDB ini file if not already present"""
     # FIXME add update trigger folder
@@ -89,7 +89,16 @@
     """Actually start the CouchDB process"""
     local_exec = local_files.COUCH_EXEC_COMMAND + ['-b']
     try:
-        retcode = subprocess.call(local_exec, shell=False)
+        # subprocess is buggy.  Chad patched, but that takes time to propagate.
+        proc = subprocess.Popen(local_exec)
+        while True:
+            try:
+                retcode = proc.wait()
+                break
+            except OSError, e:
+                if e.errno == errno.EINTR:
+                    continue
+                raise
         if retcode < 0:
             print >> sys.stderr, "Child was terminated by signal", -retcode
         elif retcode > 0:
@@ -118,15 +127,30 @@
     html = fp.read()
     fp.close()
 
-    time.sleep(1)
-    pid = desktopcouch.find_pid()
-    port = desktopcouch.find_port(pid)
+    port = None
+    for retry in xrange(10000, 0, -1):
+        pid = desktopcouch.find_pid(start_if_not_running=False)
+        try:
+            port = desktopcouch.find_port(pid)
+            break
+        except RuntimeError, e:
+            if retry == 1:
+                raise
+            time.sleep(0.01)
+            continue
 
-    fp = open(bookmark_file, "w")
-    fp.write(html.replace("[[COUCHDB_PORT]]", port))
-    fp.close()
-    print "Browse your desktop CouchDB at file://%s" % \
-      os.path.realpath(bookmark_file)
+    if port is None:
+        print "We couldn't find desktop-CouchDB's network port.  Bookmark file not written."
+        try:
+            os.remove(bookmark_file)
+        except OSError:
+            pass
+    else:
+        fp = open(bookmark_file, "w")
+        fp.write(html.replace("[[COUCHDB_PORT]]", port))
+        fp.close()
+        print "Browse your desktop CouchDB at file://%s" % \
+          os.path.realpath(bookmark_file)
 
 def start_couchdb():
     """Execute each step to start a desktop CouchDB"""
@@ -135,6 +159,7 @@
     update_design_documents()
     write_bookmark_file()
 
+
 if __name__ == "__main__":
     start_couchdb()
     print "Desktop CouchDB started"

=== added file 'desktopcouch/stop_local_couchdb.py'
--- desktopcouch/stop_local_couchdb.py	1970-01-01 00:00:00 +0000
+++ desktopcouch/stop_local_couchdb.py	2009-08-12 14:26:14 +0000
@@ -0,0 +1,49 @@
+#!/usr/bin/python
+# Copyright 2009 Canonical Ltd.
+#
+# This file is part of desktopcouch.
+#
+#  desktopcouch is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License version 3
+# as published by the Free Software Foundation.
+#
+# desktopcouch is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with desktopcouch.  If not, see <http://www.gnu.org/licenses/>.
+#
+# Author: Chad Miller <[e-mail]>
+"""
+Stop local CouchDB server.
+"""
+
+import os
+import desktopcouch
+import time
+import signal
+import errno
+
+def stop_couchdb():
+    pid = desktopcouch.find_pid(start_if_not_running=False)
+    while pid is not None:
+        try:
+            os.kill(pid, signal.SIGTERM)
+        except OSError, e:
+            if e.errno == errno.ESRCH:
+                break
+            raise
+
+        for retry in xrange(300):
+            try:
+                os.kill(pid, 0)  # test existence. sig-zero is special.
+            except OSError:
+                break
+            time.sleep(0.01)
+
+        pid = desktopcouch.find_pid(start_if_not_running=False)
+
+if __name__ == "__main__":
+    stop_couchdb()