```Python hl_lines="9"
{!../../docs_src/behind_a_proxy/tutorial004.py!}
```

这样，就不会在 OpenAPI 概图中包含服务器了。

## 挂载子应用

如需挂载子应用（详见 [子应用 - 挂载](sub-applications.md){.internal-link target=_blank}），也要通过 `root_path` 使用代理，这与正常应用一样，别无二致。

OAuth2 with scopes is the mechanism used by many big authentication providers, like Facebook, Google, GitHub, Microsoft, Twitter, etc. They use it to provide specific permissions to users and applications.

Every time you "log in with" Facebook, Google, GitHub, Microsoft, Twitter, that application is using OAuth2 with scopes.

///

All the documentation is in Markdown format in the directory `./docs/en/`.

Many of the tutorials have blocks of code.

In most of the cases, these blocks of code are actual complete applications that can be run as is.

In fact, those blocks of code are not written inside the Markdown, they are Python files in the `./docs_src/` directory.

For active-active replication, automatic failover occurs on `GET/HEAD` operations if object or object version requested qualifies for replication and is missing on one site, but present on the other. This allows the applications to take full advantage of two-way replication even before the two sites get fully synced.

			// subsequent lifecycle policy applications
			objectInfos = append(objectInfos, obj)
			continue
		}

		// NoncurrentDays not passed yet.
		if time.Now().UTC().Before(lifecycle.ExpectedExpiryTime(obj.SuccessorModTime, event.NoncurrentDays)) {
			// add this version back to remaining versions for
			// subsequent lifecycle policy applications
			objectInfos = append(objectInfos, obj)
			continue

 * is satisfied. The limit is not strict: the cache may temporarily exceed it while waiting for
 * files to be deleted. The limit does not include filesystem overhead or the cache journal so
 * space-sensitive applications should set a conservative limit.
 *
 * Clients call [edit] to create or update the values of an entry. An entry may have only one editor
 * at one time; if a value is not available to be edited then [edit] will return null.
 *

### Create Database Tables on Startup

We will create the database tables when the application starts.

{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[32:37] hl[35:37] *}

Here we create the tables on an application startup event.

For production you would probably use a migration script that runs before you start your app. 🤓

/// tip

   *
   * <p>As long as there are applications that assume that all IP addresses are IPv4 addresses and
   * can therefore be converted safely to integers (for whatever purpose) this function can be used
   * to handle IPv6 addresses as well until the application is suitably fixed.
   *

// out of HTTP "chunked" format before returning it.
// The s3ChunkedReader returns io.EOF when the final 0-length chunk is read.
//
// NewChunkedReader is not needed by normal applications. The http package
// automatically decodes chunking when reading response bodies.
func newSignV4ChunkedReader(req *http.Request, trailer bool) (io.ReadCloser, APIErrorCode) {

COPY ./requirements.txt /app/requirements.txt

RUN pip install --no-cache-dir --upgrade -r /app/requirements.txt

COPY ./app /app
```

### 🦏 🈸

🚥 👆 ⏩ 📄 🔃 🏗 [🦏 🈸 ⏮️ 💗 📁](../tutorial/bigger-applications.md){.internal-link target=_blank}, 👆 `Dockerfile` 💪 ↩️ 👀 💖:

```Dockerfile hl_lines="7"
FROM tiangolo/uvicorn-gunicorn-fastapi:python3.9

COPY ./requirements.txt /app/requirements.txt