nixos/tests/ceph-single-node: add ceph dashboard test coverage

  # For other ways to deploy a ceph cluster, look at the documentation at

  # https://docs.ceph.com/docs/master/

  testScript = ''

    import json

    start_all()

    monA.wait_for_unit("network.target")

    monA.wait_for_open_port(8080)

    monA.wait_until_succeeds("curl -q --fail http://localhost:8080")

    monA.wait_until_succeeds("ceph -s | grep 'HEALTH_OK'")

    # Initialize dashboard creds

    monA.succeed(

        "echo 'foo bar baz qux' > /tmp/dashboard_pw",

        "ceph dashboard ac-user-create admin -i /tmp/dashboard_pw administrator",

    )

    # Get dashboard auth token

    auth_payload = json.dumps({"username": "admin", "password": "foo bar baz qux"})

    auth_response = json.loads(monA.succeed(

        f"curl --fail -s -X POST -H 'Accept: application/vnd.ceph.api.v1.0+json' -H 'Content-Type: application/json' -d '{auth_payload}' http://localhost:8080/api/auth",

    ))

    token = auth_response["token"]

    # Check cluster health via dashboard API

    health = json.loads(monA.succeed(

        f"curl --fail -s -H 'Accept: application/vnd.ceph.api.v1.0+json' -H 'Authorization: Bearer {token}' http://localhost:8080/api/health/minimal",

    ))

    assert health["health"]["status"] == "HEALTH_OK"

  '';

in

{