Add support for issuing a container update to gcs

internal/cow/cow.go

@@ -80,4 +80,6 @@ type Container interface {
 	// container to be terminated by some error condition (including calling
 	// Close).
 	Wait() error
+	// Modify sends a request to modify container resources
+	Modify(ctx context.Context, config interface{}) error
 }

internal/gcs/guestconnection.go

@@ -190,6 +190,25 @@ func (gc *GuestConnection) DeleteContainerState(ctx context.Context, cid string)
 	return gc.brdg.RPC(ctx, rpcDeleteContainerState, &req, &resp, false)
 }
 
+func (gc *GuestConnection) UpdateContainer(ctx context.Context, cid string, resources interface{}) (err error) {
+	ctx, span := trace.StartSpan(ctx, "gcs::GuestConnection::UpdateContainer")
+	defer span.End()
+	defer func() { oc.SetSpanStatus(span, err) }()
+	span.AddAttributes(trace.StringAttribute("cid", cid))
+
+	resourcesJSON, err := json.Marshal(resources)
+	if err != nil {
+		return err
+	}
+
+	req := updateContainerRequest{
+		requestBase: makeRequest(ctx, cid),
+		Resources:   string(resourcesJSON),
+	}
+	var resp responseBase
+	return gc.brdg.RPC(ctx, rpcUpdateContainer, &req, &resp, false)
+}
+
 // Close terminates the guest connection. It is undefined to call any other
 // methods on the connection after this is called.
 func (gc *GuestConnection) Close() error {

internal/gcs/protocol.go

@@ -58,6 +58,7 @@ const (
 	rpcNegotiateProtocol
 	rpcDumpStacks
 	rpcDeleteContainerState
+	rpcUpdateContainer
 	rpcLifecycleNotification
 )
 
@@ -118,6 +119,8 @@ func (typ msgType) String() string {
 		s += "DumpStacks"
 	case rpcDeleteContainerState:
 		s += "DeleteContainerState"
+	case rpcUpdateContainer:
+		s += "UpdateContainer"
 	case rpcLifecycleNotification:
 		s += "LifecycleNotification"
 	default:
@@ -358,3 +361,8 @@ type containerGetPropertiesResponseV2 struct {
 	responseBase
 	Properties containerPropertiesV2
 }
+
+type updateContainerRequest struct {
+	requestBase
+	Resources string
+}

internal/gcs/resourcepaths.go

@@ -0,0 +1,10 @@
+package gcs
+
+const (
+	// silo container resources paths
+	siloDeviceResourcePath          string = "Container/Devices/Generic"
+	siloMappedDirectoryResourcePath string = "Container/MappedDirectories"
+	siloMappedPipeResourcePath      string = "Container/MappedPipes"
+	siloMemoryResourcePath          string = "Container/Memory/SizeInMB"
+	siloRegistryFlushStatePath      string = "Container/RegistryFlushState"
+)

internal/schema1/schema1.go

@@ -218,6 +218,7 @@ type GuestDefinedCapabilities struct {
 	SignalProcessSupported        bool `json:",omitempty"`
 	DumpStacksSupported           bool `json:",omitempty"`
 	DeleteContainerStateSupported bool `json:",omitempty"`
+	UpdateContainerSupported      bool `json:",omitempty"`
 }
 
 // GuestConnectionInfo is the structure of an iterm return by a GuestConnection call on a utility VM

internal/uvm/update.go

@@ -0,0 +1,12 @@
+package uvm
+
+import (
+	"context"
+)
+
+func (uvm *UtilityVM) UpdateContainer(ctx context.Context, cid string, resources interface{}) error {
+	if uvm.gc == nil || !uvm.guestCaps.UpdateContainerSupported {
+		return nil
+	}
+	return uvm.gc.UpdateContainer(ctx, cid, resources)
+}