About LEAP command line interface
=================================

This gem installs an executable 'leap' that allows you to manage servers using the leap platform.

Installation
=================================

Prerequisites:

    sudo apt-get install ruby ruby-dev rsync openssh-client

To install leap command system-wide:

    sudo gem install leap_cli

To install without root privileges:

    gem install leap_cli --user-install

To run from a clone of the git repo, see "Development", below.

Usage
=================================

Run `leap help` for a usage instructions.

Here is an example usage:

    leap new-provider provider
    cd provider
    edit configuration files (see below)
    leap compile

Directories and Files
=================================

The general structure of leap project looks like this:

    my_leap_project/                 # your project directory
      leap_platform/                 # a clone of the leap_platform puppet recipes
      provider/                      # your provider-specific configurations

The "leap" command should be run from within the "provider" directory.

Within the "provider" directory:

    nodes/               # one configuration file per node (i.e. server)
    services/            # nodes inherit from these files if specified in node config.
    tags/                # nodes inherit from these files if specified in node config.
    files/               # text and binary files needed for services and nodes, including keypairs
    users/               # crypto key material for sysadmins
    common.yaml          # all nodes inherit these options
    provider.yaml        # global service provider definition

Configuration Files
=================================

All configuration files are in JSON format. For example

    {
      "key1": "value1",
      "key2": "value2"
    }

Keys should match /[a-z0-9_]/

Unlike traditional JSON, comments are allowed. If the first non-whitespace character is '#' the line is treated as a comment.

    # this is a comment
    {
      # this is a comment
      "key": "value"  # this is an error
    }

Options in the configuration files might be nested. For example:

    {
      "openvpn": {
        "ip_address": "1.1.1.1"
      }
    }

If the value string is prefixed with an '=' character, the value is evaluated as ruby. For example

    {
      "domain": {
        "public": "domain.org"
      }
      "api_domain": "= 'api.' + domain.public"
    }

In this case, "api_domain" will be set to "api.domain.org".

The following methods are available to the evaluated ruby:

* nodes -- A list of all nodes. This list can be filtered.

* global.services -- A list of all services.

* global.tags -- A list of all tags.

* file(file_path) -- Inserts the full contents of the file. If the file is an erb
  template, it is rendered. The file is searched for by first checking platform
  and then provider/files,

* variable -- Any variable inherited by a particular node is available
  by just referencing it using either hash notation or object notation
  (i.e. self['domain']['public'] or domain.public). Circular
  references are not allowed, but otherwise it is ok to nest
  evaluated values in other evaluated values.


Node Configuration
=================================

The name of the file will be the hostname of the node.

An example configuration "nodes/dns-europe.json"

    {
       "services": "dns",
       "tags": ["production", "europe"],
       "ip_address": "1.1.1.1"
    }

This node will have hostname "dns-europe" and it will inherit from the following files (in this order):

    common.json
    services/dns.json
    tags/europe.json
    tags/production.json

Development
=================================

How to set up your environment for developing the ``leap`` command.

Prerequisites
---------------------------------

Debian Squeeze

    sudo apt-get install git ruby ruby-dev rubygems
    sudo gem install bundler rake
    export PATH=$PATH:/var/lib/gems/1.8/bin

Debian Wheezy

    sudo apt-get install git ruby ruby-dev bundler

Ubuntu

    sudo apt-get install git ruby ruby-dev
    sudo gem install bundler

Install from git
--------------------------------------

Download the source:

    git clone git://leap.se/leap_cli      # clone leap_cli code
    cd leap_cli

Running as a gem
--------------------------------------

To install ``leap`` as a gem, do this:

    cd leap_cli
    rake build
    rake install

And then make sure your PATH is set to include where leap is installed.
It should warn you if this is not the case.

Running from the source directory
--------------------------------------

To run the ``leap`` command directly from the source tree, you need to install
the required gems using ``bundle`` and symlink ``bin/leap`` into your path:

    cd leap_cli
    bundle                        # install required gems
    ln -s `pwd`/bin/leap ~/bin    # link executable somewhere in your bin path
    which leap                    # make sure you will run leap_cli/bin/leap
    leap help

If you get an error, make sure to check ``which leap``. Some versions of ``bundle`` will
incorrectly install a broken ``leap`` command in the gem bin directory when you do ``bundle``.

Why not use ``bundle exec leap`` to run the command? This works, so long as your current
working directory is under leap_cli. Because the point is to be able to run ``leap`` in
other places, it is easier to create the symlink. If you run ``leap`` directly, and not via
the command launcher that rubygems installs, leap will run in a mode that simulates
``bundle exec leap`` (i.e. only gems included in Gemfile are allow to be loaded).