diff options
Diffstat (limited to 'docs/tutorial/index.md')
| -rw-r--r-- | docs/tutorial/index.md | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/docs/tutorial/index.md b/docs/tutorial/index.md new file mode 100644 index 0000000..863ba6d --- /dev/null +++ b/docs/tutorial/index.md @@ -0,0 +1,72 @@ +--- +next_page: app.md +--- + +## The command you just ran + +Congratulations! You have started the container for this tutorial! +Let's first explain the command that you just ran. In case you forgot, +here's the command: + +```cli +docker run -d -p 80:80 docker/getting-started +``` + +You'll notice a few flags being used. Here's some more info on them: + +- `-d` - run the container in detached mode (in the background) +- `-p 80:80` - map port 80 of the host to port 80 in the container +- `docker/getting-started` - the image to use + +!!! info "Pro tip" + You can combine single character flags to shorten the full command. + As an example, the command above could be written as: + ``` + docker run -dp 80:80 docker/getting-started + ``` + +## The Docker Dashboard + +Before going too far, we want to highlight the Docker Dashboard, which gives +you a quick view of the containers running on your machine. It gives you quick +access to container logs, lets you get a shell inside the container, and lets you +easily manage container lifecycle (stop, remove, etc.). + +To access the dashboard, follow the instructions in the +[Docker Desktop manual](https://docs.docker.com/desktop/). If you open the dashboard +now, you will see this tutorial running! The container name (`jolly_bouman` below) is a +randomly created name. So, you'll most likely have a different name. + + + + +## What is a container? + +Now that you've run a container, what _is_ a container? Simply put, a container is +simply another process on your machine that has been isolated from all other processes +on the host machine. That isolation leverages [kernel namespaces and cgroups](https://medium.com/@saschagrunert/demystifying-containers-part-i-kernel-space-2c53d6979504), features that have been +in Linux for a long time. Docker has worked to make these capabilities approachable and easy to use. + +!!! info "Creating Containers from Scratch" + If you'd like to see how containers are built from scratch, Liz Rice from Aqua Security + has a fantastic talk in which she creates a container from scratch in Go. While she makes + a simple container, this talk doesn't go into networking, using images for the filesystem, + and more. But, it gives a _fantastic_ deep dive into how things are working. + + <iframe width="560" height="315" src="https://www.youtube-nocookie.com/embed/8fi7uSYlOdc" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe> + +## What is a container image? + +When running a container, it uses an isolated filesystem. This custom filesystem is provided +by a **container image**. Since the image contains the container's filesystem, it must contain everything +needed to run an application - all dependencies, configuration, scripts, binaries, etc. The +image also contains other configuration for the container, such as environment variables, +a default command to run, and other metadata. + +We'll dive deeper into images later on, covering topics such as layering, best practices, and more. + +!!! info + If you're familiar with `chroot`, think of a container as an extended version of `chroot`. The + filesystem is simply coming from the image. But, a container adds additional isolation not + available when simply using chroot. + |