Simplify state reconciliation and support changing Softnet settings (#364)

* Simplify state reconciliation and support changing Softnet settings

* Remove unused "updateFunc" parameter from syncOnDiskVMs()

* Don't take an address of a loop variable

* ensure → ensures

* updateVMState(): don't forget to update VMState

* Introduce TestSpecUpdateSoftnet integration test

* Update OpenAPI specification to include generation/observedGeneration

pkg/client/vms.go

@@ -3,11 +3,12 @@ package client
 import (
 	"context"
 	"fmt"
-	"github.com/cirruslabs/orchard/pkg/resource/v1"
 	"net"
 	"net/http"
 	"net/url"
 	"strconv"
+
+	"github.com/cirruslabs/orchard/pkg/resource/v1"
 )
 
 type VMsService struct {
@@ -78,6 +79,17 @@ func (service *VMsService) Update(ctx context.Context, vm v1.VM) (*v1.VM, error)
 	return &updatedVM, nil
 }
 
+func (service *VMsService) UpdateState(ctx context.Context, vm v1.VM) (*v1.VM, error) {
+	var updatedVM v1.VM
+	err := service.client.request(ctx, http.MethodPut, fmt.Sprintf("vms/%s/state", url.PathEscape(vm.Name)),
+		vm, &updatedVM, nil)
+	if err != nil {
+		return &updatedVM, err
+	}
+
+	return &updatedVM, nil
+}
+
 func (service *VMsService) Delete(ctx context.Context, name string) error {
 	err := service.client.request(ctx, http.MethodDelete, fmt.Sprintf("vms/%s", url.PathEscape(name)),
 		nil, nil, nil)

pkg/resource/v1/cmp_test.go

@@ -0,0 +1,14 @@
+package v1_test
+
+import (
+	"testing"
+
+	v1 "github.com/cirruslabs/orchard/pkg/resource/v1"
+	"github.com/google/go-cmp/cmp"
+)
+
+// TestVM ensures that v1.VM and its embedded structs can be compared
+// using github.com/google/go-cmp/cmp without causing panics.
+func TestVM(t *testing.T) {
+	cmp.Equal(v1.VM{}, v1.VM{})
+}

pkg/resource/v1/v1.go

@@ -22,18 +22,17 @@ type Meta struct {
 }
 
 type VM struct {
-	Image                string          `json:"image,omitempty"`
-	ImagePullPolicy      ImagePullPolicy `json:"imagePullPolicy,omitempty"`
-	CPU                  uint64          `json:"cpu,omitempty"`
-	Memory               uint64          `json:"memory,omitempty"`
-	DiskSize             uint64          `json:"diskSize,omitempty"`
-	NetSoftnetDeprecated bool            `json:"net-softnet,omitempty"`
-	NetSoftnet           bool            `json:"netSoftnet,omitempty"`
-	NetSoftnetAllow      []string        `json:"netSoftnetAllow,omitempty"`
-	NetSoftnetBlock      []string        `json:"netSoftnetBlock,omitempty"`
-	NetBridged           string          `json:"net-bridged,omitempty"`
-	Headless             bool            `json:"headless,omitempty"`
-	Nested               bool            `json:"nested,omitempty"`
+	Image           string          `json:"image,omitempty"`
+	ImagePullPolicy ImagePullPolicy `json:"imagePullPolicy,omitempty"`
+	CPU             uint64          `json:"cpu,omitempty"`
+	Memory          uint64          `json:"memory,omitempty"`
+	DiskSize        uint64          `json:"diskSize,omitempty"`
+	NetBridged      string          `json:"net-bridged,omitempty"`
+	Headless        bool            `json:"headless,omitempty"`
+	Nested          bool            `json:"nested,omitempty"`
+
+	VMSpec
+	VMState
 
 	// Status field is used to track the lifecycle of the VM associated with this resource.
 	Status        VMStatus `json:"status,omitempty"`
@@ -88,9 +87,29 @@ type VM struct {
 	ScheduledAt time.Time `json:"scheduled_at,omitempty"`
 	StartedAt   time.Time `json:"started_at,omitempty"`
 
+	// Generation is incremented by the controller each time
+	// the resource's specification is changed.
+	//
+	// At some point we'll move Generation field to the Metadata
+	// structure as it can be useful for other resources too.
+	Generation uint64 `json:"generation"`
+
 	Meta
 }
 
+type VMSpec struct {
+	NetSoftnetDeprecated bool     `json:"net-softnet,omitempty"`
+	NetSoftnet           bool     `json:"netSoftnet,omitempty"`
+	NetSoftnetAllow      []string `json:"netSoftnetAllow,omitempty"`
+	NetSoftnetBlock      []string `json:"netSoftnetBlock,omitempty"`
+}
+
+type VMState struct {
+	// ObservedGeneration corresponds to the Generation of VM specification
+	// on which the worker had acted upon.
+	ObservedGeneration uint64 `json:"observedGeneration"`
+}
+
 type Event struct {
 	Kind      EventKind `json:"kind,omitempty"`
 	Timestamp int64     `json:"timestamp,omitempty"`
@@ -134,8 +153,9 @@ const (
 type ControllerCapability string
 
 const (
-	ControllerCapabilityRPCV1 ControllerCapability = "rpc-v1"
-	ControllerCapabilityRPCV2 ControllerCapability = "rpc-v2"
+	ControllerCapabilityRPCV1           ControllerCapability = "rpc-v1"
+	ControllerCapabilityRPCV2           ControllerCapability = "rpc-v2"
+	ControllerCapabilityVMStateEndpoint ControllerCapability = "vm-state-endpoint"
 )
 
 type ControllerCapabilities []ControllerCapability