chore: add api docs server to control-plane-dev

Adds an API docs server to the `control-plane-dev` configuration. You'll
be able to access the API documentation at `http://localhost:8999` when
you run `make dev-watch`.

Being able to view the API docs in this format makes it easier to review
some parts of the generated OpenAPI spec, such as request and response
examples.

PLAT-86

Author: jason-lynch

docker/control-plane-dev/docker-compose.yaml

@@ -44,3 +44,11 @@ services:
       - PGEDGE_HTTP__PORT=3002
       - PGEDGE_EMBEDDED_ETCD__PEER_PORT=2580
       - PGEDGE_EMBEDDED_ETCD__CLIENT_PORT=2579
+  api-docs:
+    image: redocly/redoc
+    ports:
+      - 8999:80
+    volumes:
+      - ../../api/v1/gen/http:/usr/share/nginx/html/specs
+    environment:
+      - SPEC_URL=specs/openapi3.yaml

docs/running-locally-docker.md

@@ -14,6 +14,7 @@ Control Plane cluster that runs in Docker via Docker Compose.
   - [Development workflow](#development-workflow)
     - [Rebuilding the `control-plane` binary](#rebuilding-the-control-plane-binary)
     - [Debugging](#debugging)
+  - [API documentation](#api-documentation)
 
 ## Prerequisites
 
@@ -183,3 +184,14 @@ This is an example remote debugging configuration for VSCode:
 ```
 
 After attaching the debugger, the server will start normally.
+
+## API documentation
+
+The `docker-compose.yaml` file for this configuration includes an API
+documentation server. You can access the documentation in your browser at
+http://localhost:8999.
+
+This uses the OpenAPI spec from the `api/v1/gen` directory and generates the
+documentation on the client side. When you regenerate the OpenAPI spec, for
+example by running `make -C api generate`, you only need to refresh the page to
+see the updates.