Saturday, July 21, 2007

Capistrano 2.0

Posted by jamis

Capistrano 2.0 is real. (What is Capistrano?)

Install it thus:

gem install capistrano

It’s been through four preview releases, and has seen significant changes since 1.4.1. If you’re currently using 1.4.1, be sure to check out the upgrade documentation at If you’re altogether new to Capistrano, you might like to read about getting started.

Since the last preview release (number four, version 1.99.3), the changes are primarily bug fixes, but the following featureish modifications snuck in, too:

  • The uploader has added a tiny bit of sleep to prevent the CPU from going bonkers during uploads.
  • You can specify the $CAPISTRANO:HOST$ placeholder in the filenames that you give to “put”, and it will be replaced with the actual host that the file is being uploaded to.

Also, some people reported SFTP uploads were hanging for them. If this happens to you, try adding the following line to the top of your recipe file:

set :synchronous_connect, true

That will cause connections to the servers to be established serially, rather than in parallel, so if you’ve got a lot of servers that you are connecting to, it might make things a bit time-consuming. However, this appeared to work around the hanging SFTP issue.

You can read the complete changelog here. If you are using Capistrano at all, please also consider joining the mailing list, it’s a great place to share tips and report issues.


Yes, there are a few of these. Two are of immediate significance:

  1. If you try to use the ‘put’ command to upload a file to two or more hosts via a gateway, you run a good chance of encountering “corrupted mac” errors. This is due to design flaws in Net::SSH and Net::SFTP, and (to my knowledge) cannot be worked around. The current best practice is to upload to a single host, and then use scp or rsync from the remote hosts to pull the file.
  2. A very few people have reported commands hanging inexplicably and infrequently. I suspect this is also due to flaws in Net::SSH, but I’m not certain yet.