The metadata.rb is the core file that gives extemely useful data about the cookbook. Also if you noticed when you uploaded the cookbook the version was [0.0.0].
root@chef-book:~# knife cookbook upload base
Uploading base [0.0.0]
Uploaded 1 cookbook.
root@chef-book:~#The metadata.rb controls the version number like above, and a lot other basic generic data. If you recall back to the knife.rb section where you created the cookbook, new_cookbook/metadata.rb was created. If you have blown it away, this is what it looks like:
name 'new_cookbook'
maintainer 'YOUR_COMPANY_NAME'
maintainer_email 'YOUR_EMAIL'
license 'All rights reserved'
description 'Installs/Configures new_cookbook'
long_description IO.read(File.join(File.dirname(__FILE__), 'README.md'))
version '0.1.0'Pretty straight forward eh? Now because we didn't have metadata.rb in your base cookbook, you couldn't control your version number. Lets do that now:
name 'base'
maintainer 'JJ Asghar'
maintainer_email '[email protected]'
license 'All rights reserved'
description 'Installs/Configures base'
long_description IO.read(File.join(File.dirname(__FILE__), 'README.md'))
version '0.1.0'As of chef 11.8, the name is required for converges to complete. I've searched high and low for the ticket that's associated with this; but here's the general release notes. Luckily the error is extremely obvious if you don't have have name, and the fix is to add it. ;)
And lets upload it:
root@chef-book:~/cookbooks/base# cd ..
root@chef-book:~/cookbooks# knife cookbook upload base
ERROR: Errno::ENOENT: No such file or directory - /root/cookbooks/base/README.md
root@chef-book:~/cookbooks#Do'h! It seem we need a README.md now, this is great habit to have. I'm lazy so I'll just touch the file:
root@chef-book:~/cookbooks# touch /root/cookbooks/base/README.md
root@chef-book:~/cookbooks# knife cookbook upload base
Uploading base [0.1.0]
Uploaded 1 cookbook.
root@chef-book:~/cookbooks#Now check out your cookbooks on your server and you should see [0.1.0].
Lets take a step back from chef and talk about versioning. The chef community has basiclly decided that Semantic Versioning is the defacto standard for cookbooks. There is A TON of data on that link, but to sum it up I explain it like this:
A patch change is "x.y.Z". Anything larger than a patch, example adding a test, is a "x.Y.z" change. Anything that adds new functionality for an internal cookbook is "X.y.z," if you are pulling public run cookbooks stick with the system they use.
It's not 100% accurate, but it's a great rule of thumb.
Ok, so why should I care about versioning, well it's good to track your changes right? It's also a great way "pin" versions for different environments, which I'll talk about next.