Templates vs. cookbook files in Chef

Once of the questions I ask myself when writing Chef code is, “Should I use a template resource here, or a cookbook file?”

My first thought was to use the resource like it was intended. If I needed to modify the file’s contents, I’d use a template. If the contents where static, I’d use a cookbook file. So anything in the /etc/rsyslog.d/ folder was a template, while the /etc/rsyslog.conf file itself was a cookbook file.

This worked for a little while, like three months and ten cookbooks. Six months and 40 cookbooks later, things started getting out of hand. I found I was having to convert cookbook files over to templates as I found new parts that needed customizing. Plus, it got hard to remember if a particular default setting was in a cookbook file or a template.

For now, I’ve settled on a simple rule of thumb. If it’s ASCII, it’s a template. If it’s binary, it’s a cookbook file. This keeps everything text together where I can reference it, and simplifies making changes when that need arrises.