Let's check back those deployment concepts from before:

* Security - HTTPS
* Running on startup
* Restarts
* **Replication (the number of processes running)**
* Memory
* Previous steps before starting

Up to this point, with all the tutorials in the docs, you have probably been running a **server program**, for example, using the `fastapi` command, that runs Uvicorn, running a **single process**.

            InputStream is3 = mockResource.openInputStream(1, 2, 3);

            // Then
            assertNotNull(is1, "Default input stream should not be null");
            assertNotNull(is2, "Input stream with sharing should not be null");
            assertNotNull(is3, "Input stream with full params should not be null");
            assertSame(mockInputStream, is1, "Should return expected input stream");

    @Override
    protected void startUp() {
      assertFalse(startUpCalled);
      assertFalse(runCalled);
      assertFalse(shutDownCalled);
      startUpCalled = true;
      assertEquals(State.STARTING, state());
    }

    @Override
    protected void run() {
      assertTrue(startUpCalled);
      assertFalse(runCalled);
      assertFalse(shutDownCalled);
      runCalled = true;

class="external-link" target="_blank">using the 'X-' prefix</a>.

But if you have custom headers that you want a client in a browser to be able to see, you need to add them to your CORS configurations (read more in [CORS (Cross-Origin Resource Sharing)](../tutorial/cors.md){.internal-link target=_blank}), using the parameter `expose_headers` documented in <a href="https://www.starlette.io/middleware/#corsmiddleware" class="external-link" target="_blank">Starlette's CORS docs</a>....

 * proportional to the highest valued character that has a replacement. For example a replacement
 * map containing the single character '{@literal \}u1000' will require approximately 16K of memory.
 * As such sharing this data structure between escaper instances is the primary goal of this class.
 *
 * @author David Beaumont
 * @since 15.0
 */
@GwtCompatible
public final class ArrayBasedEscaperMap {
  /**

## MinIO configuration YAML

MinIO now supports starting the server arguments and configuration via a YAML configuration file. This YAML configuration describes everything that can be configured in a MinIO setup, such as '--address', '--console-address' and command line arguments for the MinIO server.

	  # tags:
	  #   - key: "name"
	  #     value: "pick*" # match objects with tag 'name', with all values starting with 'pick'

	  ## NOTE: metadata filter not supported when "source" is non MinIO.
	  # metadata:
	  #   - key: "content-type"
	  #     value: "image/*" # match objects with 'content-type', with all values starting with 'image/'

	notify:
	  endpoint: "https://notify.endpoint" # notification endpoint to receive job status events

    validations:
      required: false
  - type: textarea
    id: what-did-you-do
    attributes:
      label: "What did you do?"
      description: "If possible, provide a recipe for reproducing the error. Starting with a Private/Incognito tab/window may help rule out problematic browser extensions."
    validations:
      required: true
  - type: textarea
    id: actual-behavior
    attributes:

### 🙅 📨

🙆 📨 ⏮️ `Origin` 🎚. 👉 💼 🛠️ 🔜 🚶‍♀️ 📨 🔘 😐, ✋️ 🔜 🔌 ☑ ⚜ 🎚 🔛 📨.

## 🌅 ℹ

🌖 ℹ 🔃 <abbr title="Cross-Origin Resource Sharing">⚜</abbr>, ✅ <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS" class="external-link" target="_blank">🦎 ⚜ 🧾</a>.

/// note | 📡 ℹ

👆 💪 ⚙️ `from starlette.middleware.cors import CORSMiddleware`.

Ви можете пізніше прочитати більше про інші middlewares в [Advanced User Guide: Advanced Middleware](../advanced/middleware.md){.internal-link target=_blank}.