Composer Monorepo Plugin
Note: this project is still experimental. Please provide feedback!
This plugin adds support for Monorepos when using Composer package manager. It
introduces a maintainable approach to managing dependencies for multiple
packages in a single repository, without losing the benefits of having explicit
dependencies for each separate package., (*1)
Repositories managed with this plugin contain two kinds of packages:, (*2)
- Composer packages defined by a single global
composer.json with all external dependencies at the root of the repository.
- Many monorepo packages in sub-folders of the project, each with its own
monorepo.json, a simplified composer.json file.
Dependencies in monorepos can be either a third party Composer package that
is listed in the composer.json or a monorepo package contained in the project., (*3)
This plugins build step generates autoloaders with vendor/autoload.php files for
each package with access to the explicitly specified dependencies only., (*4)
The following steps are performed by this plugin when building the autoloads:, (*5)
- It detects
monorepo.json files in subdirectories excluding vendor/ and marks
them as roots of packages.
- It then fetches all composer packages from the locally installed packages.
- Finally for each package with
monorepo.json it generates a
vendor/autoload.php file using all the dependencies defined in that
package from either other monorepo packages or regular Composer packages.
This plugin draws inspiration from Google Blaze/Bazel and
Facebook Buck implementing a single
monolithic repository for whole projects/company. It's the missing piece for
the monolithic repository workflow using PHP and Composer., (*6)
More details about reasoning on Gregory Szorc's blog:, (*7)
Backwards Incompatible Changes in v0.12
In v0.12 we removed the fiddler script and the possibility to build a PHAR archive.
This project is now a first-class composer plugin only and requires Composer v1.1+
for the composer monorepo: commands to be available., (*8)
The fiddler.json files must be renamed to monorepo.json., (*9)
Use v0.11.6 or lower if you don't want to break this in your project yet., (*10)
Installation
Add the composer monorepo plugin to your root composer.json with:, (*11)
$ composer require beberlei/composer-monorepo-plugin
It will be automatically added as a Composer plugin., (*12)
Usage
Whenever Composer generates autoload files (during install, update or
dump-autoload) it will find all sub-directories with monorepo.json files and
generate sub-package autoloaders for them., (*13)
You can execute the autoload generation step for just the subpackages by
calling:, (*14)
$ composer monorepo:build
You create a composer.json file in the root of your project and use
this single source of vendor libraries across all of your own packages., (*15)
This sounds counter-intuitive to the Composer approach at first, but
it simplifies dependency management for a big project massively. Usually
if you are using a composer.json per package, you have mass update sprees
where you upate some basic library like "symfony/dependency-injection" in
10-20 packages or worse, have massively out of date packages and
many different versions everywhere., (*16)
Then, each of your own package contains a monorepo.json using almost
the same syntax as Composer:, (*17)
{
"deps": [
"components/Foo",
"vendor/symfony/symfony"
],
"autoload": {
"psr-0": {"Foo\\": "src/"}
}
}
You can then run composer dump-autoload in the root directory next to
composer.json and this plugin will detect all packages, generate a custom
autoloader for each one by simulating composer dump-autoload as if a
composer.json were present in the subdirectory., (*18)
This plugin will resolve all dependencies (without version constraints, because it
is assumed the code is present in the correct versions in a monolithic
repository)., (*19)
Package names in deps are the relative directory names from the project root,
not Composer package names., (*20)
You can just require "vendor/autoload.php; in every package as if you were using Composer.
Only autoloads from the monorepo.json are included, which means all dependencies must be explicitly
specified., (*21)
Configuration Schema monorepo.json
For each package in your monolithic repository you have to add monorepo.json
that borrows from composer.json format. The following keys are usable:, (*22)
-
autoload - configures the autoload settings for the current package classes and files.
-
autoload-dev - configures dev autoload requirements. Currently always evalauted.
-
deps - configures the required dependencies in an array (no key-value pairs with versions)
using the relative path to the project root directory as a package name.
-
deps-dev - configures the required dev dependencies
Git Integration for Builds
In a monorepo, for every git commit range you want to know which components changed.
You can test with the git-changed? command:, (*23)
composer monorepo:git-changed? components/foo $TRAVIS_COMMIT_RANGE
if [ $? -eq 0 ]; then ant build fi
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