Added Daemon Api definition

docs/protocol/daemon-api.md

@@ -0,0 +1,99 @@
+# Daemon Api
+
+The Daemon Api is the api that provides the communication between the Server and a Daemon.
+All interactions are instantiated from the Server.
+<br>
+This api is used to provide the frontend cabability to instantiate game processes.
+
+## Structure
+
+The Daemon Api is something like a Rest Api on the Daemon witch is accessed from the Server.
+<br>
+Every enpoint follows the following schema: `<endpoint-collection>/<endpoint>`
+
+| Name | Description |
+|------|-------------|
+| Endpoint Collection | As the name says, a endpoint collection is a collection of endpoints. All endpoints from a collection are from the same daemon. The pupuse of a endpoint collection is to group certan enpoints. (e.g. `network` contains all endpoints related to networks) |
+| Endpoint | A endpoint is like a funtion on a daemon witch can be executed by the frontend. Mostly it changes database stated or sends notifications to other users. |
+
+## Security
+
+In normal cases all daemons are not public accessable. (e.g. secured by a firewall or Docker Networks)
+<br>
+Altrough all request must contain an api token. The api token can be configured with an environment variable on the server and dameon side.
+It is recommended to change the api token is requrlary time spans.
+
+## Request
+
+### Header
+
+The server sends the following headers:
+
+```http
+Content-Type: application/json; charset=utf-8
+Accept: application/json
+Accept-Charset: utf-8
+Authorization: <api token>
+```
+
+### Body
+
+The server sends the following parameters:
+
+```json
+{
+  "user_id": "<uuid>" // the id of the user who executed the endpoint
+  // ... - endpoint specific parameters
+}
+```
+
+## Response
+
+### Header
+
+The daemon must respond with the following headers:
+
+```http
+Content-Type: application/json; charset=utf-8
+```
+
+The status code is also pased to the frontend.
+
+### Body
+
+
+The daemon must respond with the following body:
+
+```json
+{
+  "error": "message" // optional error message
+  // ... - endpoint specific data
+}
+```
+
+## Endpoint Discovery
+
+When a server boots, it discovers all existing endpoints. Therefor it executes the discorvery endpoint for every dameon type.
+This is needed to filter out request for non-existing endpoints and to route reponses to the daemon according to the endpoint.
+<br>
+<br>
+The reponse looks like this:
+
+```json
+[
+  {
+    "id": "<endpoint collection id>",
+    "description": "<endpoint collection description>",
+    "disabled": false,
+    "endpoints": [
+      {
+        "id": "<endpoint id>",
+        "description": "<endpoint description>",
+        "disabled": false
+      }
+    ]
+  }
+]
+```
+
+__The description is currently not used.__