Create a new empty symfony project

php composer.phar create-project symfony/framework-standard-edition demo/ 2.4.1cd demo

Generate a new bundle

(for example src/Company/DemoBundle)

php app/console generate:bundlecd src/Company/DemoBundle/

Init your github repository in src/Company/DemoBundle

git inittouch README.mdgit add .git commit -m "initial commit"git remote add origin https://github.com/YourAccount/DemoBundle.gitgit push -u origin master

Add a composer.json file

src/Company/DemoBundle/composer.json:

{    "name" : "company/demobundle",    "description" : "A demo bundle",    "type" : "symfony-bundle",    "authors" : [{        "name" : "demo",        "email" : "demo@company.com"    }],    "keywords" : [        "demo bundle"    ],    "license" : [        "MIT"    ],    "require" : {    },    "autoload" : {        "psr-0" : {            "Company\\DemoBundle" : ""        }    },    "target-dir" : "Company/DemoBundle",    "repositories" : [{    }],    "extra" : {    "branch-alias" : {            "dev-master" : "some_version-dev"        }    }}

Now you have the base structure of your bundle

Use it in another project

composer.json:

    [...]    "require" : {        [...]        "company/demobundle" : "dev-master"    },    "repositories" : [{        "type" : "vcs",        "url" : "https://github.com/Company/DemoBundle.git"    }],    [...]

Do:

curl -sS https://getcomposer.org/installer | phpphp composer.phar update company/demobundle

app/AppKernel:

new Company\DemoBundle\CompanyDemoBundle(),

Work on it

• You can clone your DemoBundle in the src/Company folder, then manually install it
• You can use symlink

Conclusion

You can develop and test your bundle in your first project and use it with github and composer in your second project.

An important point to know is that you can commit into your repo from the /vendor. Indeed, composer creates a second remote called "composer" for each bundle (or package) that references the repo of the package, in order you can work on it in a working context.So the good practice is to register your package in your composer.json for all your projects and commit from your /vendor/MyCompany/MyBundle, from any project.

As a proof, just run git remote -v from any bundle in your vendor.

The bad practice would be to consider your bundle as a separate project and have symlinks with it. The main reason why this is the bad practice is that you won't be able to declare dependancies with your bundle. Moreover you'll have some difficulties with the deployment of your projects.

In Symfony4, generate:bundle command is no longer available. Instead, you may follow this tutorial.

First create a project with:

composer create-project symfony/website-skeleton my-project

Then, create a my-project/lib/AcmeFooBundle/src directory. Here will live your bundle. The namespace for this directory will be Acme\AcmeFooBundle, so if you create a service class at lib/AcmeFooBundle/src/Service/Foo.php, its namespace would be Acme\AcmeFooBundle\Service.

Now we need to tell composer autoloader to look for new classes at that new directory, so we need to edit composer.json autoload section:

"autoload": {    "psr-4": {        "Acme\\AcmeFooBundle\\": "lib/AcmeFooBundle/src/",    }}, 

and run composer dump-autoload.

Now you only need to add your bundle class to config/bundles.php:

return [    ...    Acme\AcmeFooBundle\AcmeFooBundle::class => ['all' => true],];

and dependency injection to load configuration from your bundle.

If you want to check your services before adding dependency injection, you can just autowire them at config/services.yml:

services:    ...    Acme\AcmeFooBundle\Services\Foo: ~

That's all. Follow best practices and go on coding.

PS: I've published a post with a few tips for developing Symfony reusable bundles.