A small set of command to maintain a mirror of git repositories and create a local satis repository for composer.

0.6 2014-05-16 19:17 UTC


Medusa is a command line tool that works together with Satis to create a local git mirror for your composer projects.

What the hell???

What is Medusa, what is it good for?

If you have a very slow connection, fetching your project's dependencies through composer can be a pain. My projects were taking more than half a day to update or install on my local machines because of slow networks.

Medusa will create a mirror of all these things on your local machine and let you fetch everything from there rather than fetching the whole source from Github. Each dependency is entirely mirrored, meaning you'll have all versions, tags, and branches on your local machine.


It will only work with github hosted projects for now.

It has very poor documentation.

It is a very early release, there might be bugs, and the API to use it is definitely confusing.

How to use

For now, you can do the following:

  • Download the .phar archive from the downloads section
  • Download the .phar archive for SATIS
  • Put them both in a folder on your machine
  • Inside of that folder, create a web/ and a web/repositories/ folder
  • Create a medusa.json file that looks like this:
        // vcs repositories not in packagist
        "repositories": [
                // pseudo package name; used for repo directory structure
                "name": "myvendor/package",
                "url": "git@othervcs:myvendor/package.git"
        "require": [
            //... List all the packages you want here, there dependencies can be
            // auto downloaded as well
        "repodir": "web/repositories",
        // Optional URL to satis (if not hosted locally)
        "satisurl": "",
        // Target path for generated satis configuration
        "satisconfig": "satis.json"
  • Create a satis config file skeleton like this:
        "name": "My Repository",
        "homepage": "",
        "repositories": [
            // Optionally list repositories not updateable by medusa
        "require-all": true // if you want to also mirror the dependencies from each package
  • run ./medusa.phar mirror medusa.json
  • wait a long time

During this time, medusa will first find all the dependencies you need. Then it runs git clone --mirror for each of them to create a mirror inside of the specified repodir. Finally, it updates your satis.json file with your new config.

  • Run the satis build command: ./satis.phar build satis.json web/
  • Once a day run:
    ./medusa.phar update medusa.json
    ./satis.phar build satis.json web/

To update all repos and rebuild the satis config.

Other available commands:

add [--with-deps] package [config-file]

  • --with-deps if you want to also mirror the new package's dependencies
  • package is the package name you want to mirror (eg: symfony/symfony)
  • config-file is the medusa.json config file; the specified satis.json config file will be updated

Make composer use it

Point a webserver to the web/ directory.

In your composer global config file add:

        "repositories": [
                "type": "composer",
                "url": "http://my.satis.url"