![SDS decision flow](docs/sds-flow.svg)

### Default CA Flow through istio-agent

![CA Flow](docs/ca.svg)

A single SDS request from Envoy goes through a few different layers in istio-agent.

1. First, the request is handled by the SDS server. This is mostly just an intermediate translation layer exposing

	mt.Assert(ztunnelConnected.Name(), nil, monitortest.Exactly(1))

	// we should get the fd to dev null. note that we can't assert the fd number
	// as the kernel may have given us a different number that refers to the same file.
	assert.Equal(t, len(fds), 1)
	// in theory we should close the fd, but it's just a test..

	assert.Equal(t, m.Payload.(*zdsapi.WorkloadRequest_Add).Add.Uid, uid)

         alt="Istio logo" title="Istio" height="100" width="100" />
</a>

---

**FastAPI** 💪 🛠️ ⏮️ 🙆 <abbr title="Distributed database (Big Data), also 'Not Only SQL'">☁</abbr>.

📥 👥 🔜 👀 🖼 ⚙️ **<a href="https://www.couchbase.com/" class="external-link" target="_blank">🗄</a>**, <abbr title="Document here refers to a JSON object (a dict), with keys and values, and those values can also be other JSON objects, arrays (lists), numbers, strings, booleans, etc.">📄</abbr> 🧢 ☁ 💽.

👆 💪 🛠️ ⚫️ 🙆 🎏 ☁ 💽 💖:

* **✳**
* **👸**
* **✳**

Here we'll see an example using **<a href="https://www.couchbase.com/" class="external-link" target="_blank">Couchbase</a>**, a <abbr title="Document here refers to a JSON object (a dict), with keys and values, and those values can also be other JSON objects, arrays (lists), numbers, strings, booleans, etc.">document</abbr> based NoSQL database.

You can adapt it to any other NoSQL database like:

	// and positive values indicating number of read locks
	lockMap map[string]int64

	// Refresh returns lock not found if set to true
	lockNotFound bool

	// Set to true if you want peers servers to do not respond
	responseDelay int64
}

func (l *lockServer) setRefreshReply(refreshed bool) {
	l.mutex.Lock()
	defer l.mutex.Unlock()
	l.lockNotFound = !refreshed
}

    ```console
    $ hypercorn main:app --bind 0.0.0.0:80

    Running on 0.0.0.0:8080 over http (CTRL + C to quit)
    ```

    </div>

!!! note
    The command `uvicorn main:app` refers to:

    * `main`: the file `main.py` (the Python "module").
    * `app`: the object created inside of `main.py` with the line `app = FastAPI()`.

    It is equivalent to:

    ```Python

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="6"
    {!> ../../../docs_src/security/tutorial001.py!}
    ```

!!! tip
    Here `tokenUrl="token"` refers to a relative URL `token` that we haven't created yet. As it's a relative URL, it's equivalent to `./token`.