Class: RailsInstaller

An installer for Rails applications.

The Rails Application Installer is designed to make it easy for end-users to install open-source Rails apps with a minimum amount of effort. When built properly, all the user needs to do is run:

   $ gem install my_app
   $ my_app install /some/path

To use this installer, you’ll need to create a small driver program (the ‘my_app’ program from above). Here’s a minimal example:

   #!/usr/bin/env ruby

   require 'rubygems'
   require 'rails-installer'

   class AppInstaller < RailsInstaller
     application_name 'my_shiny_metal_app'
     support_location 'our shiny website'
     rails_version '1.1.4'
   end

   # Installer program
   directory = ARGV[1]

   app = AppInstaller.new(directory)
   app.message_proc = Proc.new do |msg|
     STDERR.puts " #{msg}"
   end
   app.execute_command(*ARGV)

Place this in your application’s gem/ directory, and then add it to your .gem using the ‘executables’ gemspec option. See the examples/ directory for more complex examples.

Methods

app_name application_name backup_config_file backup_database config_file copy_files copy_gem copy_one_file create_default_config_files create_default_database_yml create_directories create_initial_database display_help execute_command expand_template_files find_source_directory fix_permissions freeze_rails get_schema_version hash_diff install install_post_hook install_pre_hook install_sequence message migrate new pre_migrate_database rails_version read_yml restore_database run_rails_tests save set_initial_port_number sha1_hash_directory_tree start stop support_location system_silently write_yml

Classes and Modules

Class RailsInstaller::Command
Class RailsInstaller::Database
Class RailsInstaller::InstallFailed
Class RailsInstaller::WebServer

Attributes

 config
 install_directory
 message_proc
 source_directory

Public Class methods

application_name(name)

The application name. Set this in your derived class.

new(install_directory)

rails_version(svn_tag)

Which Rails version this app needs. This version of Rails will be frozen into vendor/rails/

support_location(location)

The support location. This is displayed to the user at the end of the install process.

Public Instance methods

app_name()

The application name, as set by application_name.

backup_config_file()

The path to the config file that comes with the GEM

backup_database()

Backup the database

config_file()

The path to the installed config file

copy_files()

Copy files from the source directory to the target directory.

copy_gem(spec, destination)

Copy a specific gem’s contents.

copy_one_file(filename)

Copy one file from source_directory to install_directory, creating directories as needed.

create_default_config_files()

Create all default config files

create_default_database_yml()

Create the default database.yml

create_directories()

Create required directories, like tmp

create_initial_database()

Create the initial SQLite database

display_help(error=nil)

Display help.

execute_command(*args)

Execute a command-line command

expand_template_files()

Expand configuration template files.

find_source_directory(gem_name, version)

Locate the source directory for a specific Version

fix_permissions()

Clean up file and directory permissions.

freeze_rails()

Freeze to a specific version of Rails gems.

get_schema_version()

Get the current schema version

hash_diff(a, b)

Compute the different between two hashes. Returns four hashes, one contains the keys that are in ‘b’ but not in ‘a’ (added entries), the next contains keys that are in ‘a’ and ‘b’, but have different values (changed). The third contains keys that are in ‘b’ but not ‘a’ (added). The final hash contains items that are the same in each.

install(version=nil)

Install Application

install_post_hook()

Another install hook; install_post_hook runs after the final migration.

install_pre_hook()

The easy way to add steps to the installation process. install_pre_hook runs right after the DB is backed up and right before the first migration attempt.

install_sequence()

The default install sequence. Override this if you need to add extra steps to the installer.

message(string)

Display a status message

migrate()

Migrate the database

pre_migrate_database()

Pre-migrate the database. This checks to see if we’re downgrading to an earlier version of our app, and runs ‘rake migrate VERSION=…’ to downgrade the database.

read_yml(filename)

Load a yaml file

restore_database(filename)

Restore the database

run_rails_tests()

Run Rails tests. This helps verify that we have a clean install with all dependencies. This cuts down on a lot of bug reports.

save()

Save config settings

set_initial_port_number()

Pick a default port number

sha1_hash_directory_tree(directory, prefix='', hash={})

Find all files in a directory tree and return a Hash containing sha1 hashes of all files.