The build session state is managed by the `BuildSessionState` class.
An instance is created at the start of a Gradle invocation and discarded at the end of that invocation.

The build session state also includes "cross session" state that is shared with any "nested" sessions that need to be created.

### Create a callback `APIRouter`

First create a new `APIRouter` that will contain one or more callbacks.

```Python hl_lines="3  25"
{!../../../docs_src/openapi_callbacks/tutorial001.py!}
```

### Create the callback *path operation*

To create the callback *path operation* use the same `APIRouter` you created above.

    - `istio-cni-config` configmap with CNI plugin config to add to CNI plugin chained config
    - creates service-account `istio-cni` with `ClusterRoleBinding` to allow gets on pods' info and delete/modifications for recovery.

- `install-cni` container
    - copies `istio-cni` and `istio-iptables` to `/opt/cni/bin`
    - creates kubeconfig for the service account the pod runs under

    routePlanner.autoGeneratePlans = true
    routePlanner.defaultConnectionIdleAtNanos = expireTime
    val address = routePlanner.address
    val pool = routePlanner.pool

    // Connections are created as soon as a policy is set
    setPolicy(pool, address, ConnectionPool.AddressPolicy(2))
    assertThat(pool.connectionCount()).isEqualTo(2)

    // Connections are replaced if they idle out or are evicted from the pool

  private var http2Connection: Http2Connection? = null

  internal val lock: ReentrantLock = ReentrantLock()

  // These properties are guarded by [lock].

  /**
   * If true, no new exchanges can be created on this connection. It is necessary to set this to
   * true when removing a connection from the pool; otherwise a racing caller might get it from the

          if (isShutdown) return

          // If the stream ID is less than the last created ID, assume it's already closed.
          if (streamId <= lastGoodStreamId) return

          // If the stream ID is in the client's namespace, assume it's already closed.
          if (streamId % 2 == nextStreamId % 2) return

          // Create a stream.
          val headers = headerBlock.toHeaders()

                    (descriptor.containingDeclaration.source.getPsi() as? KtFunctionLiteral)?.let { parentLambda ->
                        analysisContext.analyze(parentLambda).get(BindingContext.AUTO_CREATED_IT, descriptor) != null
                    } == true
        }

    override val returnType: KtType
        get() = withValidityAssertion {

# You can define multiple automations in a .cm file, but each automation name should be unique
# within the file.  We keep each automation (or very closely related group of automations) in
# its own file.

on:
  - pr_created
  - commit
  - comment_added

automations:

  # Label changes by affected platforms (in blue)
  {% for platform in platforms %}
  platform_label_{{ platform.name }}:

But it's the simplest way to focus on the server-side of WebSockets and have a working example:

```Python hl_lines="2  6-38  41-43"
{!../../../docs_src/websockets/tutorial001.py!}
```

## Create a `websocket`

In your **FastAPI** application, create a `websocket`:

```Python hl_lines="1  46-47"
{!../../../docs_src/websockets/tutorial001.py!}
```

!!! note "Technical Details"

- All features currently used by your buckets will work as is without any changes
  - SSE (Server Side Encryption)
  - Replication (Server Side Replication)

## Prerequisites

- It is assumed you have users created and configured with relevant access policies, to start with
  use basic "readwrite" canned policy to test all the operations before you finalize on what level
  of restrictions are needed for a user.