volume create: simplify cluster volume options

Extract construction of the cluster volume spec from runCreate, and use
struct literals for the individual cluster volume options.

Also simplify topology parsing by reusing ConvertKVStringsToMap, use
slices.SortFunc for deterministic secret ordering, and use max to clamp
negative capacity values to zero.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/command/volume/create.go

@@ -4,10 +4,11 @@
 package volume
 
 import (
+	"cmp"
 	"context"
 	"errors"
 	"fmt"
-	"sort"
+	"slices"
 	"strings"
 
 	"github.com/docker/cli/cli"
@@ -117,89 +118,13 @@ func hasClusterVolumeOptionSet(flags *pflag.FlagSet) bool {
 }
 
 func runCreate(ctx context.Context, dockerCli command.Cli, options createOptions) error {
-	volOpts := client.VolumeCreateOptions{
-		Driver:     options.driver,
-		DriverOpts: options.driverOpts.GetAll(),
-		Name:       options.name,
-		Labels:     opts.ConvertKVStringsToMap(options.labels.GetSlice()),
-	}
-	if options.cluster {
-		volOpts.ClusterVolumeSpec = &volume.ClusterVolumeSpec{
-			Group: options.group,
-			AccessMode: &volume.AccessMode{
-				Scope:   volume.Scope(options.scope),
-				Sharing: volume.SharingMode(options.sharing),
-			},
-			Availability: volume.Availability(options.availability),
-		}
-
-		switch options.accessType {
-		case "mount":
-			volOpts.ClusterVolumeSpec.AccessMode.MountVolume = &volume.TypeMount{}
-		case "block":
-			volOpts.ClusterVolumeSpec.AccessMode.BlockVolume = &volume.TypeBlock{}
-		}
-
-		vcr := &volume.CapacityRange{}
-		if r := options.requiredBytes.Value(); r >= 0 {
-			vcr.RequiredBytes = r
-		}
-
-		if l := options.limitBytes.Value(); l >= 0 {
-			vcr.LimitBytes = l
-		}
-		volOpts.ClusterVolumeSpec.CapacityRange = vcr
-
-		for key, secret := range options.secrets.GetAll() {
-			volOpts.ClusterVolumeSpec.Secrets = append(
-				volOpts.ClusterVolumeSpec.Secrets,
-				volume.Secret{
-					Key:    key,
-					Secret: secret,
-				},
-			)
-		}
-		sort.SliceStable(volOpts.ClusterVolumeSpec.Secrets, func(i, j int) bool {
-			return volOpts.ClusterVolumeSpec.Secrets[i].Key < volOpts.ClusterVolumeSpec.Secrets[j].Key
-		})
-
-		// TODO(dperny): ignore if no topology specified
-		topology := &volume.TopologyRequirement{}
-		for _, top := range options.requisiteTopology.GetSlice() {
-			// each topology takes the form segment=value,segment=value
-			// comma-separated list of equal separated maps
-			segments := map[string]string{}
-			for segment := range strings.SplitSeq(top, ",") {
-				// TODO(dperny): validate topology syntax
-				k, v, _ := strings.Cut(segment, "=")
-				segments[k] = v
-			}
-			topology.Requisite = append(
-				topology.Requisite,
-				volume.Topology{Segments: segments},
-			)
-		}
-
-		for _, top := range options.preferredTopology.GetSlice() {
-			// each topology takes the form segment=value,segment=value
-			// comma-separated list of equal separated maps
-			segments := map[string]string{}
-			for segment := range strings.SplitSeq(top, ",") {
-				// TODO(dperny): validate topology syntax
-				k, v, _ := strings.Cut(segment, "=")
-				segments[k] = v
-			}
-
-			topology.Preferred = append(
-				topology.Preferred,
-				volume.Topology{Segments: segments},
-			)
-		}
-
-		volOpts.ClusterVolumeSpec.AccessibilityRequirements = topology
-	}
-
-	res, err := dockerCli.Client().VolumeCreate(ctx, volOpts)
+	res, err := dockerCli.Client().VolumeCreate(ctx, client.VolumeCreateOptions{
+		Driver:            options.driver,
+		DriverOpts:        options.driverOpts.GetAll(),
+		Name:              options.name,
+		Labels:            opts.ConvertKVStringsToMap(options.labels.GetSlice()),
+		ClusterVolumeSpec: clusterVolumeSpec(options),
+	})
 	if err != nil {
 		return err
 	}
@@ -207,3 +132,54 @@ func runCreate(ctx context.Context, dockerCli command.Cli, options createOptions
 	_, _ = fmt.Fprintln(dockerCli.Out(), res.Volume.Name)
 	return nil
 }
+
+func clusterVolumeSpec(options createOptions) *volume.ClusterVolumeSpec {
+	if !options.cluster {
+		return nil
+	}
+
+	var secrets []volume.Secret
+	for key, secret := range options.secrets.GetAll() {
+		secrets = append(secrets, volume.Secret{Key: key, Secret: secret})
+	}
+	slices.SortFunc(secrets, func(a, b volume.Secret) int {
+		return cmp.Compare(a.Key, b.Key)
+	})
+
+	accessMode := &volume.AccessMode{
+		Scope:   volume.Scope(options.scope),
+		Sharing: volume.SharingMode(options.sharing),
+	}
+	switch options.accessType {
+	case "mount":
+		accessMode.MountVolume = &volume.TypeMount{}
+	case "block":
+		accessMode.BlockVolume = &volume.TypeBlock{}
+	}
+
+	return &volume.ClusterVolumeSpec{
+		Group:      options.group,
+		AccessMode: accessMode,
+		AccessibilityRequirements: &volume.TopologyRequirement{
+			Requisite: parseTopologies(options.requisiteTopology.GetSlice()),
+			Preferred: parseTopologies(options.preferredTopology.GetSlice()),
+		},
+		CapacityRange: &volume.CapacityRange{
+			RequiredBytes: max(options.requiredBytes.Value(), 0),
+			LimitBytes:    max(options.limitBytes.Value(), 0),
+		},
+		Secrets:      secrets,
+		Availability: volume.Availability(options.availability),
+	}
+}
+
+func parseTopologies(values []string) []volume.Topology {
+	topologies := make([]volume.Topology, 0, len(values))
+	for _, top := range values {
+		// TODO(dperny): validate topology syntax
+		topologies = append(topologies, volume.Topology{
+			Segments: opts.ConvertKVStringsToMap(strings.Split(top, ",")),
+		})
+	}
+	return topologies
+}