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Recently I helped a friend debug a problem when deploying with Webistrano/Capistrano.

He was using a git repository and used SSH keys for authentication. Every time he tried to deploy he got this error:

 executing locally: "git ls-remote ssh://repo.example.com/git/myproject.git HEAD"
*** Could not save revision: Unable to resolve revision for 'HEAD' on repository 'ssh://repo.example.com/git/myproject.git'.

When running this command manually as the Webistrano user, everything worked fine.

We checked the usual suspects: the SSH key, the permissions on the SSH dirs/files, user, firewall & co. Everything seemed correct and worked when we ran the command by hand.

After a bit of tinkering I had the Eureka moment: the git command was not in $PATH when running under Passenger!

Git was installed and worked when we logged in as the Webistrano user. But when Passenger runs Webistrano it doesn't load all your shell config files. So if git is not in a standard location like /usr/bin or /bin Capistrano (which by this time will be called from Webistrano to do the actual deployment) will not find it.

I our case git was installed in /usr/local/bin and thus not in the default path. We ended up symlinking it to /usr/bin and everything worked like a charm.

I just committed a fix to Capistrano to make debugging such errors in the future easier. Capistrano will now check every local command it executes and see if it is in path. So with the latest version on github the error message would have looked like this:

 executing locally: "git ls-remote ssh://repo.example.com/git/myproject.git HEAD"
*** executable 'git' not present or not in $PATH on the local system!
*** Could not save revision: Unable to resolve revision for 'HEAD' on repository 'ssh://repo.example.com/git/myproject.git'.

So if you are running any shell commands under Passenger remember that it doesn't use a full login-shell.

I'm proud to announce Webistrano 1.3!

Webistrano is a Web UI for managing Capistrano deployments. It lets you manage projects and their stages like test, production, and staging with different settings. Those stages can then be deployed with Capistrano through Webistrano.

The 1.3 adds several new shiny features to Webistrano that make deployment easier:

• Better Git support through Capistrano 2.2
• Support for Phusion Passenger / mod_rails
• Ability to temporary disable hosts for a deployment
• A command-line interface with script/deploy
• A simple permission system

The complete changelog is available through the Webistrano project site.

One very often demanded feature is the ability to temporary disable a host for a deployment. This is helpful when you want to deploy a stage without changing the stage configuration even if one or more hosts are down:

Another scenario is when you want to execute a task only on a limited set of servers.

The script/deploy command is a nice little gem, especially useful if you want to script Webistrano:

$ ruby script/deploy 
Usage: deploy [options] project stage
    -h, --help                       This message
    -e, --environment=ENV            RAILS_ENV for Webistrano (default: production)
    -u, --username=NAME              Webistrano username to use (default: admin)
    -t, --task=NAME                  Capistrano task to invoke (default: deploy)
    -d, --description=TEXT           Deployment comment for Webistrano records

Further, Webistrano now offers built-in tasks for managing mod_rails deployments. It will override the default deploy tasks and ask for the necessary configuration entries so that using mod_rails becomes even easier.

Upgrading from previous releases is very easy, see the Upgrading wiki page.

Webistrano 1.3 can be downloaded here. Webistrano is BSD-licensed and the project site is open for everybody. Please see the project page for more documentation and screenshots. There are even some screencasts.