# OpenAPI

There are several utilities to handle OpenAPI.

# FastAPI in Containers - Docker

When deploying FastAPI applications a common approach is to build a **Linux container image**. It's normally done using <a href="https://www.docker.com/" class="external-link" target="_blank">**Docker**</a>. You can then deploy that container image in one of a few possible ways.

Using Linux containers has several advantages including **security**, **replicability**, **simplicity**, and others.

/// tip

    initializeData(out);

    data = baos.toByteArray();
  }

  private void initializeData(DataOutputStream out) throws IOException {
    /* Write out various test values NORMALLY */
    out.write(new byte[] {-100, 100});
    out.writeBoolean(true);
    out.writeBoolean(false);
    out.writeByte(100);
    out.writeByte(-100);
    out.writeByte((byte) 200);
    out.writeChar('a');

    initializeData(out);

    data = baos.toByteArray();
  }

  private void initializeData(DataOutputStream out) throws IOException {
    /* Write out various test values NORMALLY */
    out.write(new byte[] {-100, 100});
    out.writeBoolean(true);
    out.writeBoolean(false);
    out.writeByte(100);
    out.writeByte(-100);
    out.writeByte((byte) 200);
    out.writeChar('a');

"vendor/golang.org/x/crypto/cryptobyte". When a package with the
same path is imported from a package outside std or cmd, it will
be resolved normally. Consequently, a binary may be built with two
copies of a package at different versions if the package is
imported normally and vendored by the standard library.

Vendored packages are internally renamed with a "vendor/" prefix

## Security - HTTPS

In the [previous chapter about HTTPS](https.md){.internal-link target=_blank} we learned about how HTTPS provides encryption for your API.

We also saw that HTTPS is normally provided by a component **external** to your application server, a **TLS Termination Proxy**.

under the License.
-->

<!--
 | This is the toolchains file for Maven. It can be specified at two levels:
 |
 |  1. User Level. This toolchains.xml file provides configuration for a single user,
 |                 and is normally provided in ${user.home}/.m2/toolchains.xml.
 |
 |                 NOTE: This location can be overridden with the CLI option:
 |
 |                 -t /path/to/user/toolchains.xml
 |
 |  2. Installation Level.

///

## About "Form Fields"

The way HTML forms (`<form></form>`) sends the data to the server normally uses a "special" encoding for that data, it's different from JSON.

**FastAPI** will make sure to read that data from the right place instead of JSON.

/// note | "Technical Details"

Data from forms is normally encoded using the "media type" `application/x-www-form-urlencoded`.

			return svc.Name
		}
		for _, addr := range svc.Addresses {
			if addr == wl.Waypoint.Destination {
				return svc.Name
			}
		}
	}

	return "NA" // Shouldn't normally reach here
}

func serviceWaypointName(svc *ZtunnelService, services []*ZtunnelService) string {
	if svc.Waypoint == nil {
		return "None"
	}

	for _, service := range services {

# WebSockets

When defining WebSockets, you normally declare a parameter of type `WebSocket` and with it you can read data from the client and send data to it.

It is provided directly by Starlette, but you can import it from `fastapi`:

```python
from fastapi import WebSocket
```

/// tip