Name

App::Sqitch - Sane database change management

Synopsis

use App::Sqitch;
exit App::Sqitch->go;

Description

This module provides the implementation for sqitch. You probably want to read its documentation, or the tutorial. Unless you want to hack on Sqitch itself, or provide support for a new engine or command. In which case, you will find this API documentation useful.

Interface

Class Methods

go

App::Sqitch->go;

Called from sqitch, this class method parses command-line options and arguments in @ARGV, parses the configuration file, constructs an App::Sqitch object, constructs a command object, and runs it.

Constructor

new

my $sqitch = App::Sqitch->new(\%params);

Constructs and returns a new Sqitch object. The supported parameters include:

options
user_name
user_email
editor
verbosity

Accessors

user_name

user_email

editor

options

my $options = $sqitch->options;

Returns a hashref of the core command-line options.

config

my $config = $sqitch->config;

Returns the full configuration, combined from the project, user, and system configuration files.

verbosity

Instance Methods

run

$sqitch->run('echo', '-n', 'hello');

Runs a system command and waits for it to finish. Throws an exception on error. Does not use the shell, so arguments must be passed as a list. Use shell to run a command and its arguments as a single string.

engine

my $engine = $sqitch->engine(@params);

Creates and returns an engine of the appropriate subclass. Pass in additional parameters to be passed through to the engine constructor.

config_for_target

my $config = $sqitch->config_for_target($target);

Returns a hash reference representing the configuration for the specified target name or URI. The supported keys in the hash reference are:

target

The name of the target, as passed.

uri

A database URI object, to be used to connect to the target database.

registry

The name of the Sqitch registry in the target database.

If the $target argument looks like a database URI, it will simply returned in the hash reference. If the $target argument corresponds to a target configuration key, the target configuration will be returned, with the uri value a upgraded to a URI object. Otherwise returns undef.

engine_key

my $key = $sqitch->engine_key;
my $key = $sqitch->engine_key($uri);

Returns the key name of the engine. If --engine was specified, its value will be used. If the $uri argument is passed and is a URI::db object, the key will be derived from its database driver. Otherwise, the value specified for the core.engine variable will be used.

config_for_target_strict

my $config = $sqitch->config_for_target_strict($target);

Like config_for_target, but throws an exception if $target is not a URL, does not correspond to a target configuration section, or does not include a uri key. Otherwise returns the target configuration.

engine_for_target

my $engine = $sqitch->engine_for($target);

Like config_for_target_strict, but returns an App::Sqitch::Engine object. If $target is not defined or is empty, an engine will be returned for the default target.

shell

$sqitch->shell('echo -n hello');

Shells out a system command and waits for it to finish. Throws an exception on error. Always uses the shell, so a single string must be passed encapsulating the entire command and its arguments. Use quote_shell to assemble strings into a single shell command. Use run to execute a list without a shell.

quote_shell

my $cmd = $sqitch->quote_shell('echo', '-n', 'hello');

Assemble a list into a single string quoted for execution by shell. Useful for combining a specified command, such as editor(), which might include the options in the string, for example:

$sqitch->shell( $sqitch->editor, $sqitch->quote_shell($file) );

capture

my @files = $sqitch->capture(qw(ls -lah));

Runs a system command and captures its output to STDOUT. Returns the output lines in list context and the concatenation of the lines in scalar context. Throws an exception on error.

probe

my $git_version = $sqitch->capture(qw(git --version));

Like capture, but returns just the chomped first line of output.

spool

$sqitch->spool($sql_file_handle, 'sqlite3', 'my.db');
$sqitch->spool(\@file_handles, 'sqlite3', 'my.db');

Like run, but spools the contents of one or ore file handle to the standard input the system command. Returns true on success and throws an exception on failure.

trace

trace_literal

$sqitch->trace_literal('About to fuzzle the wuzzle.');
$sqitch->trace('Done.');

Send trace information to STDOUT if the verbosity level is 3 or higher. Trace messages will have trace: prefixed to every line. If it's lower than 3, nothing will be output. trace appends a newline to the end of the message while trace_literal does not.

debug

debug_literal

$sqitch->debug('Found snuggle in the crib.');
$sqitch->debug_literal('ITYM "snuggie".');

Send debug information to STDOUT if the verbosity level is 2 or higher. Debug messages will have debug: prefixed to every line. If it's lower than 2, nothing will be output. debug appends a newline to the end of the message while debug_literal does not.

info

info_literal

$sqitch->info('Nothing to deploy (up-to-date)');
$sqitch->info_literal('Going to frobble the shiznet.');

Send informational message to STDOUT if the verbosity level is 1 or higher, which, by default, it is. Should be used for normal messages the user would normally want to see. If verbosity is lower than 1, nothing will be output. info appends a newline to the end of the message while info_literal does not.

comment

comment_literal

$sqitch->comment('On database flipr_test');
$sqitch->comment_literal('Uh-oh...');

Send comments to STDOUT if the verbosity level is 1 or higher, which, by default, it is. Comments have # prefixed to every line. If verbosity is lower than 1, nothing will be output. comment appends a newline to the end of the message while comment_literal does not.

emit

emit_literal

$sqitch->emit('core.editor=emacs');
$sqitch->emit_literal('Getting ready...');

Send a message to STDOUT, without regard to the verbosity. Should be used only if the user explicitly asks for output, such as for sqitch config --get core.editor. emit appends a newline to the end of the message while emit_literal does not.

vent

vent_literal

$sqitch->vent('That was a misage.');
$sqitch->vent_literal('This is going to be bad...');

Send a message to STDERR, without regard to the verbosity. Should be used only for error messages to be printed before exiting with an error, such as when reverting failed changes. vent appends a newline to the end of the message while vent_literal does not.

page

page_literal

$sqitch->page('Search results:');
$sqitch->page("Here we go\n");

Like emit(), but sends the output to a pager handle rather than STDOUT. Unless there is no TTY (such as when output is being piped elsewhere), in which case it is sent to STDOUT. page appends a newline to the end of the message while page_literal does not. Meant to be used to send a lot of data to the user at once, such as when display the results of searching the event log:

$iter = $sqitch->engine->search_events;
while ( my $change = $iter->() ) {
    $sqitch->page(join ' - ', @{ $change }{ qw(change_id event change) });
}

warn

warn_literal

$sqitch->warn('Could not find nerble; using nobble instead.');
$sqitch->warn_literal("Cannot read file: $!\n");

Send a warning messages to STDERR. Warnings will have warning: prefixed to every line. Use if something unexpected happened but you can recover from it. warn appends a newline to the end of the message while warn_literal does not.

prompt

my $ans = $sqitch->('Why would you want to do this?', 'because');

Prompts the user for input and returns that input. Pass in an optional default value for the user to accept or to be used if Sqitch is running unattended. An exception will be thrown if there is no prompt message or if Sqitch is unattended and there is no default value.

ask_y_n

if ( $sqitch->ask_y_no('Are you sure?', 'y') ) { # do it! }

Prompts the user with a "yes" or "no" question. Returns true for "yes" and false for "no". Any answer that begins with case-insensitive "y" or "n" will be accepted as valid. If the user inputs an invalid value three times, an exception will be thrown. An exception will also be thrown if there is no message or if the optional default value does not begin with "y" or "n". As with prompt() an exception will be thrown if Sqitch is running unattended and there is no default.

Author

David E. Wheeler <david@justatheory.com>

License

Copyright (c) 2012-2018 iovation Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.