For my game project, I want to have multiple [Docker](https://www.docker.com/) containers started up at once which are all linked together by easy-to-use hostnames (not terrible auto-generated Docker hashes).

The solution to this arrived to me pretty easily thanks to my friend [@will2bill](https://twitter.com/will2bill) on Twitter who pointed out that [Docker Compose](https://docs.docker.com/compose/) is a thing! By declaring a [YAML](https://yaml.org/) manifest file called `docker-compose.yml` and filling it appropriately you can have a series of linked containers come up easily with a single command, `sudo docker-compose up -d`. I've included an example `docker-compose.yml` file directly below:

```
version: '3'
services:
  gateway:
    build: ./gateway
    ports:
      - "2222:22"
  another:
    build: ./anyway
```

As you can see, we define the version of docker-compose manifest first, then we define the services/containers that we'll want. In this case, we're creating two containers, one called `gateway` and the other called `another`. They'll both be built individually and locally from `Dockerfile`s located in their relevant directories, however you can also specify an `image` property with a Docker `image:tag` rather than using the `build` keyword. You'll also notice the `ports` array, which in this case maps port 2222 on the host to 22 on the guest container called `gateway` and allows us to SSH in from our host to the guest. Once we're inside the guest, we can simply SSH to the other box with `ssh user@another`, making it super easy for us to get around.

This is exactly what I needed for the problem, however `docker-compose` has some different features from `docker` and so the next challenge will be getting multiple `docker-compose` orchestrated container groups loaded, one per each SSH connection from a user.