NAME
App::MechaCPAN - Mechanize the installation of CPAN things.
SYNOPSIS
# Install 5.24 into local/perl/
user@host:~$ mechacpan perl 5.24
# Install Catalyst into local/
user@host:~$ mechacpan install Catalyst
# Install everything from the cpanfile into local/
# If cpanfile.snapshot exists, it will be consulted first
user@host:~$ mechacpan install
# Install perl and everything from the cpanfile into local/
# If cpanfile.snapshot exists, it will be consulted exclusivly
user@host:~$ mechacpan deploy
user@host:~$ zhuli do the thingDESCRIPTION
App::MechaCPAN Mechanizes the installation of perl and CPAN modules. It is designed to be small and focuses more on installing things in a self-contained manner. That means that everything is installed into a local/ directory.
MechaCPAN was created because installation of a self-contained deployment required at least 4 tools:
- plenv/Perl-Build or perlbrew to manage perl installations
- cpanm to install packages
- local::lib to use locally installed modules
- carton to manage and deploy exact package versions
In development these tools are invaluable, but when deploying a package, installing at least 4 packages from github, CPAN and the web just for a small portion of each tool is more than needed. App::MechaCPAN aims to be a single tool that can be used for deploying packages in a automated fashion.
App::MechaCPAN focuses on the aspects of these tools needed for deploying packages to a system. For instance, it will read and use carton's cpanfile.snapshot files, but cannot create them. To create cpanfile.snapshot files, you must use carton.
Should I use App::MechaCPAN instead of <tool>
Probably not, no. It can be used in place of some tools, but it's focus is not on the features a developer needs. If your needs are very simple and you don't need many options, you might be able to get away with only using App::MechaCPAN. However be prepared to run into limitations quickly.
USING FOR DEPLOYMENTS
COMMANDS
user@host:~/project/$ ls -la
drwxr-xr-x 6 user users 20480 Jan 18 13:00 .
drwxr-xr-x 25 user users 4096 Jan 18 13:00 ..
drwxr-xr-x 8 user users 4096 Jan 18 13:05 .git
-rw-r--r-- 1 user users 7 Jan 18 13:06 .perl-version
-rw-r--r-- 1 user users 109 Jan 18 13:06 cpanfile
drwxr-xr-x 3 user users 4096 Jan 18 13:10 lib
user@host:~/project/$ mechacpan deployThat command will do 2 things:
- Install perl
-
It will install perl into the directory local/perl. It will use the version in
.perl-versionto decide what version will be installed. - Install modules
-
Then it will use the installed perl to install all the module dependencies that are listed in the cpanfile.
COMMANDS
Perl
user@host:~$ mechacpan perl 5.24The perl command is used to install perl into local/. This removes the packages dependency on the operating system perl. By default, it tries to be helpful and include lib/ and local/ into @INC automatically, but this feature can be disabled. See App::MechaCPAN::Perl for more details.
Install
user@host:~$ mechacpan install CatalystThe install command is used for installing specific modules. All modules are installed into the local/ directory. See See App::MechaCPAN::Install for more details.
Deploy
user@host:~$ mechacpan deployThe deploy command is used for automating a deployment. It will install both perl and all the modules specified from the cpanfile. If there is a cpanfile.snapshot that was created by Carton, deploy will treat the modules lised in the snapshot file as the only modules available to install. See App::MechaCPAN::Deploy for more details.
SCRIPT RESTART WARNING
This module WILL restart the running script IF it's used as a module (e.g. with use) and the perl that is running is not the version installed in local/. It does this at two points: First right before run-time and Second right after a perl is installed into local/.
The scripts and modules that come with App::MechaCPAN are prepared to handle this. If you use App::MechaCPAN as a module, you should to be prepared to handle it as well.
This means that any END and DESTROY blocks WILL NOT RUN. Anything created with File::Temp will be cleaned up, however.
AUTHOR
Jon Gentle <cpan@atrodo.org>
COPYRIGHT
Copyright 2017- Jon Gentle
LICENSE
This is free software. You may redistribute copies of it under the terms of the Artistic License 2 as published by The Perl Foundation.