Even if they are all in `localhost`, they use different protocols or ports, so, they are different "origins".

## Steps

So, let's say you have a frontend running in your browser at `http://localhost:8080`, and its JavaScript is trying to communicate with a backend running at `http://localhost` (because we don't specify a port, the browser will assume the default port `80`).

Pydantic's `orm_mode` will tell the Pydantic *model* to read the data even if it is not a `dict`, but an ORM model (or any other arbitrary object with attributes).

This way, instead of only trying to get the `id` value from a `dict`, as in:

```Python
id = data["id"]
```

it will also try to get it from an attribute, as in:

```Python
id = data.id
```

So, if your application consumes a lot of memory (for example with machine learning models), and your server has a lot of CPU cores **but little memory**, then your container could end up trying to use more memory than what is available, and degrading performance a lot (or even crashing). 🚨

### Create a `Dockerfile`

Here's how you would create a `Dockerfile` based on this image:

```Dockerfile