Adding extra_hosts to the compose file stubs for automatic host.docker.internal mapping

[vs0uz4]

Fantastic implementation of xdebug 3.0 by Nick Haynes in PR [#209], I think it's very pertinent to have the option of a step debugger built into the container.

However, in the PR description, which has even been approved and merged, Nick Haynes cites the issue that host.docker.internal is not available in containers running in linux environments, and the fact that users of this OS have to update the environment variable in their projects using the command below:

docker inspect -f {{range.NetworkSettings.Networks}}{{.Gateway}}{{end}} <container-name>

However, I would like to make a small contribution, which I believe is valid, as it will bring greater compatibility between Windows, Mac and Linux environments, so that we do not need extra commands to detect the IP of the Host machine.

The version used in the template (docker-compose.stub) of sail already supports the addition of hostname mappings, with this we were able to solve the host.docker.internal issue no longer needing the use of extra commands to detect the IP address of the host machine. For this we can add the option extra_hosts to the service where we create the application container, so we will be adding a mapping for host.docker.internal pointing to the host machine.

extra_hosts:
    - 'host.docker.internal:host-gateway'

More information about the extra_hosts option can be found in the documentation at compose-file#extra_hosts

A small change that would have value. The laravel.test service would look like this:

laravel.test:
    build:
        context: ./vendor/laravel/sail/runtimes/8.0
        dockerfile: Dockerfile
        args:
            WWWGROUP: '${WWWGROUP}'
    image: sail-8.0/app
    extra_hosts:
        - 'host.docker.internal:host-gateway'
    networks:
        - sail
    ports:
        - '${APP_PORT:-80}:80'
    environment:
        WWWUSER: '${WWWUSER}'
        LARAVEL_SAIL: 1
        XDEBUG_MODE: '${SAIL_XDEBUG_MODE:-off}'
        XDEBUG_CONFIG: '${SAIL_XDEBUG_CONFIG:-client_host=host.docker.internal}'
    volumes:
        - '.:/var/www/html'
    depends_on:
        - mysql
        - redis

With this, every time we create/start the application container the host.docker.internal mapping will be created and will point to the host machine. Inside the container in your /etc/hosts file, the appropriate appointment records will be created, as shown in the example below:

127.0.0.1       localhost
::1             localhost ip6-localhost ip6-loopback
fe00::0         ip6-localnet
ff00::0         ip6-mcastprefix
ff02::1         ip6-allnodes
ff02::2         ip6-allrouters
172.17.0.1      host.docker.internal

[vs0uz4]

This small change helps not only in the xdebug issue, but also for any need to make a connection from the container to the host machine. Like for example spatie's "ray".