hgweb: add --port-file flag

Summary:
This allows us to specify `-p 0 --port-file X` to get the port assigned in
an atomic way. So there won't be "server failed to start" caused by race
conditions in tests.

Reviewed By: DurhamG

Differential Revision: D6925397

fbshipit-source-id: 5bbb61b7eb2695f0a673afdb0730d2a61827f8b3

mercurial/commands.py

@@ -4681,6 +4681,8 @@ def root(ui, repo):
     ('', 'webdir-conf', '', _('name of the hgweb config file (DEPRECATED)'),
      _('FILE')),
     ('', 'pid-file', '', _('name of file to write process ID to'), _('FILE')),
+    ('', 'port-file', '',
+     _("name of file to write port to (useful with '-p 0')"), _('FILE')),
     ('', 'stdio', None, _('for remote clients (ADVANCED)')),
     ('', 'cmdserver', '', _('for remote clients (ADVANCED)'), _('MODE')),
     ('t', 'templates', '', _('web templates to use'), _('TEMPLATE')),

mercurial/hgweb/__init__.py

@@ -54,7 +54,11 @@ class httpservice(object):
         util.setsignalhandler()
         self.httpd = server.create_server(self.ui, self.app)
 
-        if self.opts['port'] and not self.ui.verbose:
+        portfile = self.opts.get('port_file')
+        if portfile:
+            util.writefile(portfile, '%s' % self.httpd.port)
+
+        if (self.opts['port'] or portfile) and not self.ui.verbose:
             return
 
         if self.httpd.prefix:
@@ -75,7 +79,7 @@ class httpservice(object):
         fqaddr = self.httpd.fqaddr
         if r':' in fqaddr:
             fqaddr = r'[%s]' % fqaddr
-        if self.opts['port']:
+        if self.opts['port'] or portfile:
             write = self.ui.status
         else:
             write = self.ui.write

mercurial/server.py

@@ -40,6 +40,9 @@ def runservice(opts, parentfn=None, initfn=None, runfn=None, logfile=None,
         # Signal child process startup with file removal
         lockfd, lockpath = tempfile.mkstemp(prefix='hg-service-')
         os.close(lockfd)
+        portpath = opts.get('port_file')
+        if portpath:
+            util.tryunlink(portpath)
         try:
             if not runargs:
                 runargs = util.hgcmd() + pycompat.sysargv[1:]
@@ -54,6 +57,8 @@ def runservice(opts, parentfn=None, initfn=None, runfn=None, logfile=None,
                     del runargs[i:i + 2]
                     break
             def condfn():
+                if portpath and not os.path.exists(portpath):
+                    return False
                 return not os.path.exists(lockpath)
             pid = util.rundetached(runargs, condfn)
             if pid < 0:

tests/test-completion.t

@@ -187,6 +187,7 @@ Show the options for the "serve" command
   --pager
   --pid-file
   --port
+  --port-file
   --prefix
   --profile
   --quiet
@@ -238,7 +239,7 @@ Show all commands + options
   pull: update, force, rev, bookmark, branch, ssh, remotecmd, insecure
   push: force, rev, bookmark, branch, new-branch, pushvars, ssh, remotecmd, insecure
   remove: after, force, subrepos, include, exclude
-  serve: accesslog, daemon, daemon-postexec, errorlog, port, address, prefix, name, web-conf, webdir-conf, pid-file, stdio, cmdserver, templates, style, ipv6, certificate, read-only, subrepos
+  serve: accesslog, daemon, daemon-postexec, errorlog, port, address, prefix, name, web-conf, webdir-conf, pid-file, port-file, stdio, cmdserver, templates, style, ipv6, certificate, read-only, subrepos
   status: all, modified, added, removed, deleted, clean, unknown, ignored, no-status, terse, copies, print0, rev, change, include, exclude, subrepos, template
   summary: remote
   update: clean, check, merge, date, rev, tool