Allow creating VMs with implicit CPU and memory (#243)

* Allow creating VMs with implicit CPU and memory

* Clarify why cpu/memory can be 0 a bit better

* Controller(API): don't forget to update DefaultCPU and DefaultMemory

* Add an integration test for implicit CPU and memory

internal/tests/implicit_cpu_memory_test.go

@@ -0,0 +1,64 @@
+package tests_test
+
+import (
+	"context"
+	"github.com/cirruslabs/orchard/internal/tests/devcontroller"
+	"github.com/cirruslabs/orchard/internal/tests/wait"
+	v1 "github.com/cirruslabs/orchard/pkg/resource/v1"
+	"github.com/stretchr/testify/require"
+	"testing"
+	"time"
+)
+
+func TestImplicitCPUMemory(t *testing.T) {
+	ctx := context.Background()
+
+	// Create a development environment
+	devClient, _, _ := devcontroller.StartIntegrationTestEnvironmentWithAdditionalOpts(t,
+		false, nil,
+		true, nil,
+	)
+
+	// Create a worker with default CPU and memory values
+	const workerName = "worker"
+
+	_, err := devClient.Workers().Create(ctx, v1.Worker{
+		Meta: v1.Meta{
+			Name: workerName,
+		},
+		Resources: map[string]uint64{
+			v1.ResourceTartVMs: 2,
+		},
+		DefaultCPU:    12,
+		DefaultMemory: 3456,
+	})
+	require.NoError(t, err)
+
+	// Create a VM with implicit CPU and memory
+	vmName := "test-vm"
+
+	require.NoError(t, devClient.VMs().Create(ctx, &v1.VM{
+		Meta: v1.Meta{
+			Name: vmName,
+		},
+		Image:  "example.com/doesnt/matter:latest",
+		Status: v1.VMStatusPending,
+	}))
+
+	// Wait for the VM to be assigned
+	require.True(t, wait.Wait(2*time.Minute, func() bool {
+		vm, err := devClient.VMs().Get(context.Background(), vmName)
+		require.NoError(t, err)
+
+		t.Logf("Waiting for the VM %s to be assigned to a worker", vmName)
+
+		return vm.Worker == workerName
+	}), "VM was %s expected to be assigned to the worker %q, but was assigned to the worker %q",
+		vmName, workerName)
+
+	// Ensure that the VM is using default CPU and memory values from the worker
+	vm, err := devClient.VMs().Get(context.Background(), vmName)
+	require.NoError(t, err)
+	require.EqualValues(t, 12, vm.AssignedCPU)
+	require.EqualValues(t, 3456, vm.AssignedMemory)
+}