[Docker](https://docs.docker.com/get-docker/) and[Coder](../install/index.md)

installed on it.

- When setting up your computer or computing instance, make sure to install Docker first, then Coder. Otherwise, you'll need to add the`coder` user to the`docker` group.

- The URL for your Coder instance. If you're running Coder locally, the default

URL is[http://127.0.0.1:3000](http://127.0.0.1:3000).

- A text editor. For this tour, we use[GNU nano](https://nano-editor.org/).

The main part of a Coder template is a[Terraform](https://terraform.io)`tf`

server essentially runs a`terraform apply` every time a workspace is created,

started, or stopped.

Here's a simplified diagram that shows the main parts of the template we'll

create.

`Dockerfile`.

mkdir template-tour

cd template-tour

mkdir build

nano build/Dockerfile

mkdir -p template-tour/build&&cd$_

nano Dockerfile

You'll enter a simple`Dockerfile` that starts with the

&& chmod 0440 /etc/sudoers.d/${USER}

USER ${USER}

WORKDIR /home/${USER}

Notice how`Dockerfile` adds a few things to the parent`ubuntu` image, which

Now you can editthe Terraform file, which provisions the workspace's resources.

Editthe Terraform file to provision the workspace's resources:

nano main.tf

Notice that the`provider` blocks for`coder` and`docker` are empty. In a more

data source provides details about the state of a workspace, such as its name,

owner, and so on. The data source also lets us know when a workspace is being

started or stopped. We'll take advantage of this information in later steps to

do these things:

started or stopped. We'll take advantage of this information in later steps to:

- Set some environment variables based on the workspace owner.

- Manage ephemeral and persistent storage.

needs`curl` access to the Coder server. Remember that we installed`curl` in

`Dockerfile`, earlier.

Thissnippetcreates the agent:

Add thissnippetbelow the last closing`}` in`main.tf` to create the agent:

Because Docker is running locally in the Coder server, there is no need to

authenticate`coder_agent`. But if your`coder_agent`were running on a remote

authenticate`coder_agent`. But if your`coder_agent`is running on a remote

host, your template would need

[authentication credentials](../admin/external-auth.md).

[web IDEs](../user-guides/workspace-access/web-ides.md) such as

[code-server](https://coder.com/docs/code-server), RStudio, and JupyterLab.

To installandcode-server in the workspace, remember that we installed it in

To install code-server in the workspace, remember that we installed it in

the`startup_script` argument in`coder_agent`. We make it available from a

workspace with a`coder_app` resource. See

[web IDEs](../user-guides/workspace-access/web-ides.md) for more examples.

You can also use a`coder_app` resource to link to external apps, such as links

to wikis or cloud consoles.

to wikis or cloud consoles:

For details, see

To set up our Docker container, our template has a`docker_image` resource that

uses`build/Dockerfile`, which we created earlier.

uses`build/Dockerfile`, which we created earlier:

Our`docker_container` resource uses`coder_workspace``start_count` to start