# Quick start - Demo

The quickest way to validate your build is to start with a demonstration HTTP setup, so you don't
need to configure credentials and certificates to use the app. This section will guide you through
it.

1. Install Docker

Instructions available [here](https://docs.docker.com/engine/install/).

2. Clone the repository:

```sh
git clone https://github.com/weiss-controls/weiss.git
```

3. Configure your environment.

First, create your `.env` file. You can start by just copying `.env.example` from the root folder:

```sh
cp .env.example .env
```

If you want to see PVs outside of localhost, adjust `DEFAULT_PROTOCOL` and `EPICS_XXX_ADDR_LIST`
accordingly.

:::{important}  
If running outside of your localhost, make sure to set `APP_HOSTNAME` to your server's IP address or
DNS name. This is used by nginx to accept requests for the right hostname and by the API's CORS
policy to allow requests from the frontend - all other origins are blocked.  
:::

The whole behaviour of the app is configured via environment variables. For this tutorial, most of
the times you don't need to change anything unless you want to. Take a look at the other variables
to get familiarized with the options.

4. Build and start the system. From the root of the repo, run:

```sh
docker compose up -d
```

Once built, three services should be running (plus an internal `storage` volume container):

- `weiss-epicsws`: the EPICS communication layer.
- `weiss-api`: the backend API for file and git interaction.
- `weiss`: WEISS front-end application - accessible at http://localhost (or your server address, if
  applicable).

:::{hint}  
If you do not have an IOC available for testing, you can run the
[demonstration IOCs](https://github.com/weiss-controls/weiss-demo-iocs). A set of OPIs using the
appropriate PVs for these can be imported from
[weiss-demo-opis](https://github.com/weiss-controls/weiss-demo-opis) using WEISS file browser.  
:::

You should now be able to import public repositories and explore the tool. For a production-grade
setup (HTTPS, enabling git write and login credentials), see `Production setup` section, starting
with [Environment variables](../production/env_variables.md).