@@ -104,7 +104,10 @@ func getMemoryResources(config containertypes.Resources) *specs.LinuxMemory {

 		memory.KernelTCP = &config.KernelMemoryTCP

 	}

-	return &memory

+	if memory != (specs.LinuxMemory{}) {

+		return &memory

+	}

+	return nil

 }

 func getPidsLimit(config containertypes.Resources) *specs.LinuxPids {

@@ -126,7 +129,7 @@ func getCPUResources(config containertypes.Resources) (*specs.LinuxCPU, error) {

 	if config.CPUShares < 0 {

 		return nil, fmt.Errorf("shares: invalid argument")

 	}

-	if config.CPUShares >= 0 {

+	if config.CPUShares > 0 {

 		shares := uint64(config.CPUShares)

 		cpu.Shares = &shares

 	}

@@ -167,7 +170,10 @@ func getCPUResources(config containertypes.Resources) (*specs.LinuxCPU, error) {

 		cpu.RealtimeRuntime = &c

 	}

-	return &cpu, nil

+	if cpu != (specs.LinuxCPU{}) {

+		return &cpu, nil

+	}

+	return nil, nil

 }

 func getBlkioWeightDevices(config containertypes.Resources) ([]specs.LinuxWeightDevice, error) {

@@ -973,13 +973,11 @@ func WithResources(c *container.Container) coci.SpecOpts {

 		if err != nil {

 			return err

 		}

-		blkioWeight := r.BlkioWeight

 		specResources := &specs.LinuxResources{

 			Memory: memoryRes,

 			CPU:    cpuRes,

 			BlockIO: &specs.LinuxBlockIO{

-				Weight:                  &blkioWeight,

 				WeightDevice:            weightDevices,

 				ThrottleReadBpsDevice:   readBpsDevice,

 				ThrottleWriteBpsDevice:  writeBpsDevice,

@@ -988,6 +986,10 @@ func WithResources(c *container.Container) coci.SpecOpts {

 			},

 			Pids: getPidsLimit(r),

 		}

+		if r.BlkioWeight != 0 {

+			w := r.BlkioWeight

+			specResources.BlockIO.Weight = &w

+		}

 		if s.Linux.Resources != nil && len(s.Linux.Resources.Devices) > 0 {

 			specResources.Devices = s.Linux.Resources.Devices

@@ -11,6 +11,8 @@ import (

 	"github.com/docker/docker/daemon/config"

 	"github.com/docker/docker/daemon/network"

 	"github.com/docker/docker/libnetwork"

+	"github.com/google/go-cmp/cmp/cmpopts"

+	"github.com/opencontainers/runtime-spec/specs-go"

 	"golang.org/x/sys/unix"

 	"gotest.tools/v3/assert"

 	is "gotest.tools/v3/assert/cmp"

@@ -212,3 +214,38 @@ func TestGetSourceMount(t *testing.T) {

 	_, _, err = getSourceMount(cwd)

 	assert.NilError(t, err)

 }

+

+func TestDefaultResources(t *testing.T) {

+	skip.If(t, os.Getuid() != 0, "skipping test that requires root") // TODO: is this actually true? I'm guilty of following the cargo cult here.

+

+	c := &container.Container{

+		HostConfig: &containertypes.HostConfig{

+			IpcMode: containertypes.IPCModeNone,

+		},

+	}

+	d := setupFakeDaemon(t, c)

+

+	s, err := d.createSpec(context.Background(), &configStore{}, c)

+	assert.NilError(t, err)

+	checkResourcesAreUnset(t, s.Linux.Resources)

+}

+

+func checkResourcesAreUnset(t *testing.T, r *specs.LinuxResources) {

+	t.Helper()

+

+	if r != nil {

+		if r.Memory != nil {

+			assert.Check(t, is.DeepEqual(r.Memory, &specs.LinuxMemory{}))

+		}

+		if r.CPU != nil {

+			assert.Check(t, is.DeepEqual(r.CPU, &specs.LinuxCPU{}))

+		}

+		assert.Check(t, is.Nil(r.Pids))

+		if r.BlockIO != nil {

+			assert.Check(t, is.DeepEqual(r.BlockIO, &specs.LinuxBlockIO{}, cmpopts.EquateEmpty()))

+		}

+		if r.Network != nil {

+			assert.Check(t, is.DeepEqual(r.Network, &specs.LinuxNetwork{}, cmpopts.EquateEmpty()))

+		}

+	}

+}

@@ -11,15 +11,19 @@ import (

 func toContainerdResources(resources container.Resources) *libcontainerdtypes.Resources {

 	var r libcontainerdtypes.Resources

-	r.BlockIO = &specs.LinuxBlockIO{

-		Weight: &resources.BlkioWeight,

+	if resources.BlkioWeight != 0 {

+		r.BlockIO = &specs.LinuxBlockIO{

+			Weight: &resources.BlkioWeight,

+		}

 	}

-	shares := uint64(resources.CPUShares)

-	r.CPU = &specs.LinuxCPU{

-		Shares: &shares,

-		Cpus:   resources.CpusetCpus,

-		Mems:   resources.CpusetMems,

+	cpu := specs.LinuxCPU{

+		Cpus: resources.CpusetCpus,

+		Mems: resources.CpusetMems,

+	}

+	if resources.CPUShares != 0 {

+		shares := uint64(resources.CPUShares)

+		cpu.Shares = &shares

 	}

 	var (

@@ -37,17 +41,33 @@ func toContainerdResources(resources container.Resources) *libcontainerdtypes.Re

 		period = uint64(resources.CPUPeriod)

 	}

-	r.CPU.Period = &period

-	r.CPU.Quota = &quota

+	if period != 0 {

+		cpu.Period = &period

+	}

+	if quota != 0 {

+		cpu.Quota = &quota

+	}

-	r.Memory = &specs.LinuxMemory{

-		Limit:       &resources.Memory,

-		Reservation: &resources.MemoryReservation,

-		Kernel:      &resources.KernelMemory,

+	if cpu != (specs.LinuxCPU{}) {

+		r.CPU = &cpu

 	}

+	var memory specs.LinuxMemory

+	if resources.Memory != 0 {

+		memory.Limit = &resources.Memory

+	}

+	if resources.MemoryReservation != 0 {

+		memory.Reservation = &resources.MemoryReservation

+	}

+	if resources.KernelMemory != 0 {

+		memory.Kernel = &resources.KernelMemory

+	}

 	if resources.MemorySwap > 0 {

-		r.Memory.Swap = &resources.MemorySwap

+		memory.Swap = &resources.MemorySwap

+	}

+

+	if memory != (specs.LinuxMemory{}) {

+		r.Memory = &memory

 	}

 	r.Pids = getPidsLimit(resources)

new file mode 100644

@@ -0,0 +1,11 @@

+package daemon // import "github.com/docker/docker/daemon"

+

+import (

+	"testing"

+

+	"github.com/docker/docker/api/types/container"

+)

+

+func TestToContainerdResources_Defaults(t *testing.T) {

+	checkResourcesAreUnset(t, toContainerdResources(container.Resources{}))

+}

@@ -21,9 +21,7 @@ func summaryFromInterface(i interface{}) (*libcontainerdtypes.Summary, error) {

 }

 func (t *task) UpdateResources(ctx context.Context, resources *libcontainerdtypes.Resources) error {

-	// go doesn't like the alias in 1.8, this means this need to be

-	// platform specific

-	return t.Update(ctx, containerd.WithResources((*specs.LinuxResources)(resources)))

+	return t.Update(ctx, containerd.WithResources(resources))

 }

 func hostIDFromMap(id uint32, mp []specs.LinuxIDMapping) int {

@@ -27,7 +27,7 @@ func InterfaceToStats(read time.Time, v interface{}) *Stats {

 }

 // Resources defines updatable container resource values. TODO: it must match containerd upcoming API

-type Resources specs.LinuxResources

+type Resources = specs.LinuxResources

 // Checkpoints contains the details of a checkpoint

 type Checkpoints struct{}