test(grpc): e2e ForkVm boots a distinct child from a running parent

Author: markovejnovic

test/e2e/grpc_contract_test.exs

@@ -7,22 +7,35 @@ defmodule Hyper.E2e.GrpcContractTest do
   VM lifecycle are asserted over the real wire, catching proto/codec/server
   drift a BEAM-side client cannot produce (e.g. unrecognised enum integers).
 
+  Also carries one BEAM-side test of `ForkVm`: it needs a real booted parent
+  VM (Firecracker + device-mapper), which the TypeScript suite cannot boot,
+  so it drives `Hyper.Grpc.V0.Hyper.Stub` directly over the same server
+  instead.
+
   Runs only under `--only integration` on a provisioned host (CI: the
   `integration` job). Requires node/npm on PATH; installs the suite's npm
   deps on first run.
   """
   use ExUnit.Case, async: false
 
+  alias Hyper.Grpc.V0.{ForkVmRequest, ForkVmResponse, StopVmRequest}
+  alias Hyper.Grpc.V0.Hyper.Stub
+
   @moduletag :integration
   @moduletag timeout: :timer.minutes(25)
 
   @port 50_061
   @suite_dir Path.expand("../grpc", __DIR__)
 
+  # public.ecr.aws mirrors library images without Docker Hub's per-IP pull
+  # limits, which shared GHA egress IPs routinely exhaust.
+  @image System.get_env("HYPER_E2E_IMAGE", "public.ecr.aws/docker/library/alpine:3.19")
+
   setup_all do
     config = %Hyper.Cfg.Grpc{enabled: true, port: @port}
     start_supervised!({GRPC.Server.Supervisor, Hyper.Cfg.Grpc.server_options(config)})
-    :ok
+    {:ok, channel} = GRPC.Stub.connect("127.0.0.1:#{@port}", adapter: GRPC.Client.Adapters.Gun)
+    {:ok, channel: channel}
   end
 
   test "TypeScript contract suite passes against the live server" do
@@ -39,6 +52,24 @@ defmodule Hyper.E2e.GrpcContractTest do
     assert status == 0, "TypeScript gRPC contract suite failed (exit #{status}); see output above"
   end
 
+  test "ForkVm boots a distinct child from a running parent", %{channel: channel} do
+    assert {:ok, img_id} = Hyper.Img.OciLoader.load(@image)
+
+    assert {:ok, parent} = Hyper.create_vm(%Hyper.Vm.Spec{img_id: img_id, type: :micro})
+    on_exit(fn -> Hyper.Node.stop_image_vm(parent) end)
+
+    parent_id = Hyper.id(parent)
+    assert parent_id, "Hyper.id/1 returned nil for a freshly-created VM"
+
+    assert {:ok, %ForkVmResponse{vm_id: child_id, node: child_node}} =
+             Stub.fork_vm(channel, %ForkVmRequest{vm_id: parent_id})
+
+    assert is_binary(child_id) and child_id != parent_id
+    assert child_node != ""
+
+    on_exit(fn -> Stub.stop_vm(channel, %StopVmRequest{vm_id: child_id}) end)
+  end
+
   defp ensure_node_deps! do
     if not File.dir?(Path.join(@suite_dir, "node_modules")) do
       {out, status} = System.cmd("npm", ["ci"], cd: @suite_dir, stderr_to_stdout: true)