Sunzi
=====

```
"The supreme art of war is to subdue the enemy without fighting." - Sunzi
```

Sunzi is the easiest [server provisioning](http://en.wikipedia.org/wiki/Provisioning#Server_provisioning) utility designed for mere mortals. If Chef or Puppet is driving you nuts, try Sunzi!

Sunzi assumes that modern Linux distributions have (mostly) sane defaults and great package managers.

Its design goals are:

* **It's just shell script.** No clunky Ruby DSL involved. Most of the information about server configuration on the web is written in shell commands. Just copy-paste them, rather than translate it into an arbitrary DSL. Also, Bash is the greatest common denominator on minimum Linux installs.
* **Focus on diff from default.** No big-bang overwriting. Append or replace the smallest possible piece of data in a config file. Loads of custom configurations make it difficult to understand what you are really doing.
* **Always use the root user.** Think twice before blindly assuming you need a regular user - it doesn't add any security benefit for server provisioning, it just adds extra verbosity for nothing. However, it doesn't mean that you shouldn't create regular users with Sunzi - feel free to write your own recipes.
* **Minimum dependencies.** No configuration server required. You don't even need a Ruby runtime on the remote server.

### What's new:

Please see the [CHANGELOG](https://github.com/kenn/sunzi/blob/master/CHANGELOG.md).

Quickstart
----------

Install:

```bash
$ [sudo] gem install sunzi
```

Go into your project directory (if it's a Rails project, `config` would be a good place to start with), then:

```bash
$ sunzi create
```

It generates a `sunzi` folder along with subdirectories and templates. Inside `sunzi`, there are `sunzi.yml` and `install.sh`. Those two are the most important files that you mainly work on.

Go into the `sunzi` directory, then run `sunzi deploy`:

```bash
$ cd sunzi
$ sunzi deploy example.com
```

Now, what it actually does is:

1. Compile `sunzi.yml` to generate variables and retrieve remote recipes, then copy files into the `compiled` directory
1. SSH to `example.com` and login as `root`
1. Transfer the content of the `compiled` directory to the remote server and extract in `$HOME/sunzi`
1. Run `install.sh` on the remote server

As you can see, all you need to do is edit `install.sh` and add some shell commands. That's it.

A Sunzi project without any recipes or roles is totally fine, so that you can start small, go big as you get along.

Commands
--------

```bash
$ sunzi                                           # Show command help
$ sunzi create                                    # Create a new Sunzi project
$ sunzi deploy [user@host:port] [role] [--sudo]   # Deploy Sunzi project
```

Directory structure
-------------------

Here's the directory structure that `sunzi create` automatically generates:

```bash
sunzi/
  install.sh      # main script
  sunzi.yml       # add custom variables and remote recipes here

  recipes/        # put commonly used scripts here, referred from install.sh
    sunzi.sh
  roles/          # when role is specified, scripts here will be concatenated
    db.sh         # to install.sh in the compile phase
    web.sh
  files/          # put any files to be transferred

  compiled/       # everything under this folder will be transferred to the
                  # remote server (do not edit directly)
```

How do you pass dynamic values?
-------------------------------

In the compile phase, variables defined in `sunzi.yml` are accessible from any files in the form of `<%= @vars.ruby_version %>`

For instance, given the following `install.sh`:

```bash
echo "Goodbye <%= @vars.goodbye %>, Hello <%= @vars.hello %>!"
```

With `sunzi.yml`:

```yaml
vars:
  goodbye: Chef
  hello: Sunzi
```

Now, you get the following result.

```
Goodbye Chef, Hello Sunzi!
```

Remote Recipes
--------------

Recipes can be retrieved remotely via HTTP. Put a URL in the recipes section of `sunzi.yml`, and Sunzi will automatically load the content and put it into the `compiled/recipes` folder in the compile phase.

For instance, if you have the following line in `sunzi.yml`,

```yaml
recipes:
  rvm: https://raw.github.com/kenn/sunzi-recipes/master/ruby/rvm.sh
```

`rvm.sh` will be available and you can refer to that recipe by `source recipes/rvm.sh`.

You may find sample recipes in this repository useful: https://github.com/kenn/sunzi-recipes

Role-based configuration
------------------------

You probably have different configurations between **web servers** and **database servers**.

No problem - how Sunzi handles role-based configuration is refreshingly simple.

Shell scripts under the `roles` directory, such as `web.sh` or `db.sh`, are automatically recognized as a role. The role script will be appended to `install.sh` at deploy, so you should put common configurations in `install.sh` and role specific procedures in the role script.

For instance, when you set up a new web server, deploy with a role name:

```bash
sunzi deploy example.com web
```

It is equivalent to running `install.sh`, followed by `web.sh`.

Vagrant
-------

If you're using Sunzi with [Vagrant](http://vagrantup.com/), make sure that you have a root access via SSH.

An easy way is to edit `Vagrantfile`:

```ruby
Vagrant.configure("2") do |config|
  config.vm.provision "shell",
    inline: "sudo echo 'root:vagrant' | /usr/sbin/chpasswd"
  end
end
```

and now run `vagrant up`, it will change the root password to `vagrant`.

Also keep in mind that you need to specify the port number 2222.

```bash
$ sunzi deploy localhost:2222
```

Demonstration Videos
-------

You can watch video on how to deploy a Rails 4.1 app with Sunzi and Capistrano 3 at http://youtu.be/3mwupXqtkmg