Changeset 1408 for branches/locker-dev/locker/deploy/bin

Timestamp:

Jan 7, 2010, 12:32:45 AM (15 years ago)

Author:

mitchb

Message:

Make Rails autoinstalls pick up code changes automatically
Ordinarily, a Rails app in production mode running as an fcgi
will continue to use old code, necessitating being killed on
all of our servers that have an instance of it hanging around.
This patch causes the fcgi to notice application changes and
reload itself automatically, providing functionality similar
to the enhancement we made for Django in r1278.  However, unlike
Django, the Rails fcgi is able to reload without needing to be
killed with fire in order to avoid fcgi renegotiation issues.

This code was developed and contributed by Greg Brockman <gdb@mit.edu>.
I've just tested and incorporated it into the scripts autoinstaller.

File:

• branches/locker-dev/locker/deploy/bin/rails (modified) (1 diff)

branches/locker-dev/locker/deploy/bin/rails

@@ -114 +114 @@
 untie @railswelcome;
 
+tie my @railsfcgi, 'Tie::File', 'public/dispatch.fcgi';
+for (@railsfcgi) {
+    s/^[^#]*RailsFCGIHandler/## Commented out by scripts.mit.edu autoinstaller\n## RailsFCGIHandler/;
+}
+untie @railsfcgi;
+open RAILSFCGI, ">>public/dispatch.fcgi";
+print RAILSFCGI <<EOF;
+
+## Added by scripts.mit.edu autoinstaller to reload when app code changes
+Thread.abort_on_exception = true
+
+t1 = Thread.new do
+   RailsFCGIHandler.process!
+end
+
+t2 = Thread.new do
+   # List of directories to watch for changes before reload
+   Thread.current[:watched_dirs] = ['app', 'config', 'db', 'lib', 'public']
+   # Sample filter: /(\.rb|\.erb)\$/.  Default filter: watch all files
+   Thread.current[:watched_extensions] = //
+
+   def modified(file)
+     mtime = File.stat(file).mtime
+     Thread.current[:modifications][file] ||= mtime
+     Thread.current[:modifications][file] != mtime
+   end
+
+   # Don't symlink yourself into a loop.  Please.
+   def modified_dir(dir)
+     Dir.new(dir).each do |file|
+       absfile = File.join(dir, file)
+       if FileTest.directory? absfile
+         next if file == '.' or file == '..'
+         return true if modified_dir(absfile)
+       else
+         return true if Thread.current[:watched_extensions] =~ absfile &&
+           modified(absfile)
+       end
+     end
+     false
+   end
+
+   def reload
+     Thread.current[:modifications] = {}
+     RailsFCGIHandler.reload!
+   end
+
+   Thread.current[:modifications] = {}
+   # Wait until the modify time changes, then reload.
+   while true
+     reload if Thread.current[:watched_dirs].inject(false) {|z, dir| z ||
+       modified_dir(File.join(File.dirname(__FILE__), '..', dir))}
+     sleep 1
+   end
+end
+
+t1.join
+t2.join
+## End of scripts.mit.edu autoinstaller additions
+EOF
+
 print "Your application is located in:\n";
 print "  /mit/$USER/web_scripts/$addrend/\n";