Tiller is a tool that generates configuration files. It takes a set of templates, fills them in with values from a variety of sources (such as environment variables, Consul, YAML files, JSON from a webservice...), installs them in a specified location and then optionally spawns a child process.
You might find this particularly useful if you're using Docker, as you can ship a set of configuration files for different environments inside one container, and/or easily build "parameterized containers" which users can then configure at runtime.
However, its use is not just limited to Docker; you may also find it useful as a sort of "proxy" that can provide values to application configuration files from a data source that the application does not natively support.
It's available as a Ruby Gem, so installation should be a simple gem install tiller.
The main documentation has been updated and a searchable, easy to read version is now hosted on readthedocs.io. You can also read the raw markdown files by browsing the docs directory in this repository.
You may like to read the Quickstart guide if you want a very quick overview.
There is also a Gitter chatroom for you to ask any questions, suggest new features and talk to other users.
OK, real talk here. This project has more-or-less stalled. I hesitate to say "abandoned" because I still care about it, but I have to be honest with anyone who might be looking at using it. The thing is, my life has had a number of (positive!) changes recently such as becoming a Dad, which have led to my free project time being greatly reduced.
Also, due to job changes and the changing technology landscape I now find myself involved in, I haven't actually used Tiller for several years. On top of that, I have realised that there are several fundamental issues with Tiller that I should tackle: Things like a re-write in Golang to avoid having to drag in a full Ruby/Gem environment for the runtime, and I also now believe that the top-level construct should be the file, and not the template that generates it. This would mean, for example, that having multiple files generated from the same template would be a very simple operation. The problem with all that is again lack of time, and the fact that I really hate Go as a programming language.
So where does this leave the project ? Well, it does work and has been battle-tested over many years. Some of the extra plugins such as Consul have badly stagnated however, and no longer work with current versions of libraries/APIs. If it works for you, then great! If you're looking for updates and a fancy Tiller 2.0 then I'm afraid you're going to be kept waiting. I'm not going to say "never" because I do still have a lot of love for this project; it was the first real open-source project I made that attracted a bunch of users, contributions and a small community around it which I'll always be thankful for.
But I guess it's best for everyone if you consider it "done" and what you see is what you get. If anyone is interested in forking it and producing a "Tiller - The Next Generation" then by all means give me a shout and I'll update things with links and pointers to your project but I won't be transferring ownership/RubyGems.org ownership etc. in the interests of security.
Thanks again for everything, and stay safe out there.
-Mark Dastmalchi-Round, August 2020