builder: wire up new gc types for buildkit prune functionality

This wires up the new gc types that buildkit exposes in version 0.17.
The previous flag, `KeepBytes`, was renamed to `ReservedBytes` and two
new options, `MaxUsed` and `MinFree` were added.

`MaxUsed` corresponds to the maximum amount of space that buildkit will
use for the build cache and `MinFree` amount of free disk space for the
system to prevent the cache from using that space. This allows greater
configuration of the cache storage usage when used in situations where
docker is not the only service on the system using disk space.

Signed-off-by: Jonathan A. Sternberg <jonathan.sternberg@docker.com>

api/server/router/build/build_routes.go

@@ -177,19 +177,55 @@ func (br *buildRouter) postPrune(ctx context.Context, w http.ResponseWriter, r *
 	if err != nil {
 		return err
 	}
-	ksfv := r.FormValue("keep-storage")
-	if ksfv == "" {
-		ksfv = "0"
-	}
-	ks, err := strconv.Atoi(ksfv)
-	if err != nil {
-		return invalidParam{errors.Wrapf(err, "keep-storage is in bytes and expects an integer, got %v", ksfv)}
-	}
 
 	opts := types.BuildCachePruneOptions{
-		All:         httputils.BoolValue(r, "all"),
-		Filters:     fltrs,
-		KeepStorage: int64(ks),
+		All:     httputils.BoolValue(r, "all"),
+		Filters: fltrs,
+	}
+
+	parseBytesFromFormValue := func(name string) (int64, error) {
+		if fv := r.FormValue(name); fv != "" {
+			bs, err := strconv.Atoi(fv)
+			if err != nil {
+				return 0, invalidParam{errors.Wrapf(err, "%s is in bytes and expects an integer, got %v", name, fv)}
+			}
+			return int64(bs), nil
+		}
+		return 0, nil
+	}
+
+	version := httputils.VersionFromContext(ctx)
+	if versions.GreaterThanOrEqualTo(version, "1.48") {
+		bs, err := parseBytesFromFormValue("reserved-space")
+		if err != nil {
+			return err
+		} else if bs == 0 {
+			// Deprecated parameter. Only checked if reserved-space is not used.
+			bs, err = parseBytesFromFormValue("keep-storage")
+			if err != nil {
+				return err
+			}
+		}
+		opts.ReservedSpace = bs
+
+		if bs, err := parseBytesFromFormValue("max-used-space"); err != nil {
+			return err
+		} else {
+			opts.MaxUsedSpace = bs
+		}
+
+		if bs, err := parseBytesFromFormValue("min-free-space"); err != nil {
+			return err
+		} else {
+			opts.MinFreeSpace = bs
+		}
+	} else {
+		// Only keep-storage was valid in pre-1.48 versions.
+		bs, err := parseBytesFromFormValue("keep-storage")
+		if err != nil {
+			return err
+		}
+		opts.ReservedSpace = bs
 	}
 
 	report, err := br.backend.PruneCache(ctx, opts)

api/swagger.yaml

@@ -8994,10 +8994,29 @@ paths:
       operationId: "BuildPrune"
       parameters:
         - name: "keep-storage"
+          in: "query"
+          description: |
+            Amount of disk space in bytes to keep for cache
+
+            > **Deprecated**: This parameter is deprecated and has been renamed to "reserved-space".
+            > It is kept for backward compatibility and will be removed in API v1.49.
+          type: "integer"
+          format: "int64"
+        - name: "reserved-space"
           in: "query"
           description: "Amount of disk space in bytes to keep for cache"
           type: "integer"
           format: "int64"
+        - name: "max-used-space"
+          in: "query"
+          description: "Maximum amount of disk space allowed to keep for cache"
+          type: "integer"
+          format: "int64"
+        - name: "min-free-space"
+          in: "query"
+          description: "Target amount of free disk space after pruning"
+          type: "integer"
+          format: "int64"
         - name: "all"
           in: "query"
           type: "boolean"

api/types/types.go

@@ -169,9 +169,11 @@ type BuildCache struct {
 
 // BuildCachePruneOptions hold parameters to prune the build cache
 type BuildCachePruneOptions struct {
-	All         bool
-	KeepStorage int64
-	Filters     filters.Args
+	All           bool
+	ReservedSpace int64
+	MaxUsedSpace  int64
+	MinFreeSpace  int64
+	Filters       filters.Args
 
-	// FIXME(thaJeztah): add new options; see https://github.com/moby/moby/issues/48639
+	KeepStorage int64 // Deprecated: deprecated in API 1.48.
 }

builder/builder-next/builder.go

@@ -185,8 +185,6 @@ func (b *Builder) DiskUsage(ctx context.Context) ([]*types.BuildCache, error) {
 }
 
 // Prune clears all reclaimable build cache.
-//
-// FIXME(thaJeztah): wire up new options https://github.com/moby/moby/issues/48639
 func (b *Builder) Prune(ctx context.Context, opts types.BuildCachePruneOptions) (int64, []string, error) {
 	ch := make(chan *controlapi.UsageRecord)
 
@@ -215,6 +213,8 @@ func (b *Builder) Prune(ctx context.Context, opts types.BuildCachePruneOptions)
 			All:           pi.All,
 			KeepDuration:  int64(pi.KeepDuration),
 			ReservedSpace: pi.ReservedSpace,
+			MaxUsedSpace:  pi.MaxUsedSpace,
+			MinFreeSpace:  pi.MinFreeSpace,
 			Filter:        pi.Filter,
 		}, &pruneProxy{
 			streamProxy: streamProxy{ctx: ctx},
@@ -638,7 +638,6 @@ func toBuildkitUlimits(inp []*container.Ulimit) (string, error) {
 	return strings.Join(ulimits, ","), nil
 }
 
-// FIXME(thaJeztah): wire-up new fields; see https://github.com/moby/moby/issues/48639
 func toBuildkitPruneInfo(opts types.BuildCachePruneOptions) (client.PruneInfo, error) {
 	var until time.Duration
 	untilValues := opts.Filters.Get("until")          // canonical
@@ -693,10 +692,17 @@ func toBuildkitPruneInfo(opts types.BuildCachePruneOptions) (client.PruneInfo, e
 			}
 		}
 	}
+
+	if opts.ReservedSpace == 0 && opts.KeepStorage != 0 {
+		opts.ReservedSpace = opts.KeepStorage
+	}
+
 	return client.PruneInfo{
 		All:           opts.All,
 		KeepDuration:  until,
-		ReservedSpace: opts.KeepStorage,
+		ReservedSpace: opts.ReservedSpace,
+		MaxUsedSpace:  opts.MaxUsedSpace,
+		MinFreeSpace:  opts.MinFreeSpace,
 		Filter:        []string{strings.Join(bkFilter, ",")},
 	}, nil
 }

builder/builder-next/controller.go

@@ -2,10 +2,12 @@ package buildkit
 
 import (
 	"context"
+	"fmt"
 	"net/http"
 	"os"
 	"path/filepath"
 	"runtime"
+	"strings"
 	"time"
 
 	ctd "github.com/containerd/containerd/v2/client"
@@ -430,37 +432,29 @@ func getGCPolicy(conf config.BuilderConfig, root string) ([]client.PruneInfo, er
 	var gcPolicy []client.PruneInfo
 	if conf.GC.Enabled {
 		if conf.GC.Policy == nil {
-			var defaultKeepStorage int64
-			if conf.GC.DefaultKeepStorage != "" {
-				b, err := units.RAMInBytes(conf.GC.DefaultKeepStorage)
-				if err != nil {
-					return nil, errors.Wrapf(err, "failed to parse defaultKeepStorage")
-				}
-				defaultKeepStorage = b
+			reservedSpace, maxUsedSpace, minFreeSpace, err := parseGCPolicy(config.BuilderGCRule{
+				ReservedSpace: conf.GC.DefaultReservedSpace,
+				MaxUsedSpace:  conf.GC.DefaultMaxUsedSpace,
+				MinFreeSpace:  conf.GC.DefaultMinFreeSpace,
+			}, "default")
+			if err != nil {
+				return nil, err
 			}
-			gcPolicy = mobyworker.DefaultGCPolicy(root, defaultKeepStorage)
+			gcPolicy = mobyworker.DefaultGCPolicy(root, reservedSpace, maxUsedSpace, minFreeSpace)
 		} else {
 			gcPolicy = make([]client.PruneInfo, len(conf.GC.Policy))
 			for i, p := range conf.GC.Policy {
-				var keepStorage int64
-				if p.KeepStorage != "" {
-					b, err := units.RAMInBytes(p.KeepStorage)
-					if err != nil {
-						return nil, errors.Wrapf(err, "failed to parse keepStorage")
-					}
-					// don't set a default here, zero is a valid value when
-					// specified by the user, as the gc-policy may be determined
-					// through other filters;
-					// https://github.com/moby/moby/pull/49062#issuecomment-2554981829
-					keepStorage = b
+				reservedSpace, maxUsedSpace, minFreeSpace, err := parseGCPolicy(p, "")
+				if err != nil {
+					return nil, err
 				}
 
-				// FIXME(thaJeztah): wire up new options https://github.com/moby/moby/issues/48639
-				var err error
 				gcPolicy[i], err = toBuildkitPruneInfo(types.BuildCachePruneOptions{
-					All:         p.All,
-					KeepStorage: keepStorage,
-					Filters:     filters.Args(p.Filter),
+					All:           p.All,
+					ReservedSpace: reservedSpace,
+					MaxUsedSpace:  maxUsedSpace,
+					MinFreeSpace:  minFreeSpace,
+					Filters:       filters.Args(p.Filter),
 				})
 				if err != nil {
 					return nil, err
@@ -471,6 +465,41 @@ func getGCPolicy(conf config.BuilderConfig, root string) ([]client.PruneInfo, er
 	return gcPolicy, nil
 }
 
+func parseGCPolicy(p config.BuilderGCRule, prefix string) (reservedSpace, maxUsedSpace, minFreeSpace int64, err error) {
+	errorString := func(key string) string {
+		if prefix != "" {
+			key = prefix + strings.ToTitle(key)
+		}
+		return fmt.Sprintf("failed to parse %s", key)
+	}
+
+	if p.ReservedSpace != "" {
+		b, err := units.RAMInBytes(p.ReservedSpace)
+		if err != nil {
+			return 0, 0, 0, errors.Wrap(err, errorString("reservedSpace"))
+		}
+		reservedSpace = b
+	}
+
+	if p.MaxUsedSpace != "" {
+		b, err := units.RAMInBytes(p.MaxUsedSpace)
+		if err != nil {
+			return 0, 0, 0, errors.Wrap(err, errorString("maxUsedSpace"))
+		}
+		maxUsedSpace = b
+	}
+
+	if p.MinFreeSpace != "" {
+		b, err := units.RAMInBytes(p.MinFreeSpace)
+		if err != nil {
+			return 0, 0, 0, errors.Wrap(err, errorString("minFreeSpace"))
+		}
+		minFreeSpace = b
+	}
+
+	return reservedSpace, maxUsedSpace, minFreeSpace, nil
+}
+
 func getEntitlements(conf config.BuilderConfig) []string {
 	var ents []string
 	// Incase of no config settings, NetworkHost should be enabled & SecurityInsecure must be disabled.

builder/builder-next/worker/gc.go

@@ -5,9 +5,15 @@ import (
 	"time"
 
 	"github.com/moby/buildkit/client"
+	"github.com/moby/buildkit/util/disk"
 )
 
-const defaultCap int64 = 2e9 // 2GB
+const (
+	defaultReservedSpaceBytes      int64 = 2e9 // 2GB
+	defaultReservedSpacePercentage int64 = 10
+	defaultMaxUsedPercentage       int64 = 80
+	defaultMinFreePercentage       int64 = 20
+)
 
 // tempCachePercent represents the percentage ratio of the cache size in bytes to temporarily keep for a short period of time (couple of days)
 // over the total cache size in bytes. Because there is no perfect value, a mathematically pleasing one was chosen.
@@ -15,39 +21,57 @@ const defaultCap int64 = 2e9 // 2GB
 const tempCachePercent = math.E * math.Pi * math.Phi
 
 // DefaultGCPolicy returns a default builder GC policy
-func DefaultGCPolicy(p string, defaultKeepBytes int64) []client.PruneInfo {
-	keep := defaultKeepBytes
-	if defaultKeepBytes == 0 {
-		keep = detectDefaultGCCap(p)
+func DefaultGCPolicy(p string, reservedSpace, maxUsedSpace, minFreeSpace int64) []client.PruneInfo {
+	if reservedSpace == 0 && maxUsedSpace == 0 && minFreeSpace == 0 {
+		// Only check the disk if we need to fill in an inferred value.
+		if dstat, err := disk.GetDiskStat(p); err == nil {
+			// Fill in default values only if we can read the disk.
+			reservedSpace = diskPercentage(dstat, defaultReservedSpacePercentage)
+			maxUsedSpace = diskPercentage(dstat, defaultMaxUsedPercentage)
+			minFreeSpace = diskPercentage(dstat, defaultMinFreePercentage)
+		} else {
+			// Fill in only reserved space if we cannot read the disk.
+			reservedSpace = defaultReservedSpaceBytes
+		}
 	}
 
-	tempCacheKeepBytes := int64(math.Round(float64(keep) / 100. * float64(tempCachePercent)))
-	const minTempCacheKeepBytes = 512 * 1e6 // 512MB
-	if tempCacheKeepBytes < minTempCacheKeepBytes {
-		tempCacheKeepBytes = minTempCacheKeepBytes
+	tempCacheReservedSpace := int64(math.Round(float64(reservedSpace) / 100. * float64(tempCachePercent)))
+	const minTempCacheReservedSpace = 512 * 1e6 // 512MB
+	if tempCacheReservedSpace < minTempCacheReservedSpace {
+		tempCacheReservedSpace = minTempCacheReservedSpace
 	}
 
-	// FIXME(thaJeztah): wire up new options https://github.com/moby/moby/issues/48639
 	return []client.PruneInfo{
 		// if build cache uses more than 512MB delete the most easily reproducible data after it has not been used for 2 days
 		{
-			Filter:        []string{"type==source.local,type==exec.cachemount,type==source.git.checkout"},
-			KeepDuration:  48 * time.Hour,
-			ReservedSpace: tempCacheKeepBytes,
+			Filter:       []string{"type==source.local,type==exec.cachemount,type==source.git.checkout"},
+			KeepDuration: 48 * time.Hour,
+			MaxUsedSpace: tempCacheReservedSpace,
 		},
 		// remove any data not used for 60 days
 		{
 			KeepDuration:  60 * 24 * time.Hour,
-			ReservedSpace: keep,
+			ReservedSpace: reservedSpace,
+			MaxUsedSpace:  maxUsedSpace,
+			MinFreeSpace:  minFreeSpace,
 		},
 		// keep the unshared build cache under cap
 		{
-			ReservedSpace: keep,
+			ReservedSpace: reservedSpace,
+			MaxUsedSpace:  maxUsedSpace,
+			MinFreeSpace:  minFreeSpace,
 		},
 		// if previous policies were insufficient start deleting internal data to keep build cache under cap
 		{
 			All:           true,
-			ReservedSpace: keep,
+			ReservedSpace: reservedSpace,
+			MaxUsedSpace:  maxUsedSpace,
+			MinFreeSpace:  minFreeSpace,
 		},
 	}
 }
+
+func diskPercentage(dstat disk.DiskStat, percentage int64) int64 {
+	avail := dstat.Total / percentage
+	return (avail/(1<<30) + 1) * 1e9 // round up
+}

builder/builder-next/worker/gc_unix.go

@@ -1,17 +0,0 @@
-//go:build !windows
-
-package worker
-
-import (
-	"syscall"
-)
-
-func detectDefaultGCCap(root string) int64 {
-	var st syscall.Statfs_t
-	if err := syscall.Statfs(root, &st); err != nil {
-		return defaultCap
-	}
-	diskSize := int64(st.Bsize) * int64(st.Blocks) //nolint unconvert
-	avail := diskSize / 10
-	return (avail/(1<<30) + 1) * 1e9 // round up
-}

builder/builder-next/worker/gc_windows.go

@@ -1,7 +0,0 @@
-//go:build windows
-
-package worker
-
-func detectDefaultGCCap(root string) int64 {
-	return defaultCap
-}

client/build_prune.go

@@ -21,7 +21,19 @@ func (cli *Client) BuildCachePrune(ctx context.Context, opts types.BuildCachePru
 	if opts.All {
 		query.Set("all", "1")
 	}
-	query.Set("keep-storage", strconv.Itoa(int(opts.KeepStorage)))
+
+	if opts.KeepStorage != 0 {
+		query.Set("keep-storage", strconv.Itoa(int(opts.KeepStorage)))
+	}
+	if opts.ReservedSpace != 0 {
+		query.Set("reserved-space", strconv.Itoa(int(opts.ReservedSpace)))
+	}
+	if opts.MaxUsedSpace != 0 {
+		query.Set("max-used-space", strconv.Itoa(int(opts.MaxUsedSpace)))
+	}
+	if opts.MinFreeSpace != 0 {
+		query.Set("min-free-space", strconv.Itoa(int(opts.MinFreeSpace)))
+	}
 	f, err := filters.ToJSON(opts.Filters)
 	if err != nil {
 		return nil, errors.Wrap(err, "prune could not marshal filters option")

daemon/config/builder.go

@@ -11,9 +11,37 @@ import (
 
 // BuilderGCRule represents a GC rule for buildkit cache
 type BuilderGCRule struct {
-	All         bool            `json:",omitempty"`
-	Filter      BuilderGCFilter `json:",omitempty"`
-	KeepStorage string          `json:",omitempty"`
+	All           bool            `json:",omitempty"`
+	Filter        BuilderGCFilter `json:",omitempty"`
+	ReservedSpace string          `json:",omitempty"`
+	MaxUsedSpace  string          `json:",omitempty"`
+	MinFreeSpace  string          `json:",omitempty"`
+}
+
+func (x *BuilderGCRule) UnmarshalJSON(data []byte) error {
+	var xx struct {
+		All           bool            `json:",omitempty"`
+		Filter        BuilderGCFilter `json:",omitempty"`
+		ReservedSpace string          `json:",omitempty"`
+		MaxUsedSpace  string          `json:",omitempty"`
+		MinFreeSpace  string          `json:",omitempty"`
+
+		// Deprecated option is now equivalent to ReservedSpace.
+		KeepStorage string `json:",omitempty"`
+	}
+	if err := json.Unmarshal(data, &xx); err != nil {
+		return err
+	}
+
+	x.All = xx.All
+	x.Filter = xx.Filter
+	x.ReservedSpace = xx.ReservedSpace
+	x.MaxUsedSpace = xx.MaxUsedSpace
+	x.MinFreeSpace = xx.MinFreeSpace
+	if x.ReservedSpace == "" {
+		x.ReservedSpace = xx.KeepStorage
+	}
+	return nil
 }
 
 // BuilderGCFilter contains garbage-collection filter rules for a BuildKit builder
@@ -56,9 +84,38 @@ func (x *BuilderGCFilter) UnmarshalJSON(data []byte) error {
 
 // BuilderGCConfig contains GC config for a buildkit builder
 type BuilderGCConfig struct {
-	Enabled            bool            `json:",omitempty"`
-	Policy             []BuilderGCRule `json:",omitempty"`
-	DefaultKeepStorage string          `json:",omitempty"`
+	Enabled              bool            `json:",omitempty"`
+	Policy               []BuilderGCRule `json:",omitempty"`
+	DefaultReservedSpace string          `json:",omitempty"`
+	DefaultMaxUsedSpace  string          `json:",omitempty"`
+	DefaultMinFreeSpace  string          `json:",omitempty"`
+}
+
+func (x *BuilderGCConfig) UnmarshalJSON(data []byte) error {
+	var xx struct {
+		Enabled              bool            `json:",omitempty"`
+		Policy               []BuilderGCRule `json:",omitempty"`
+		DefaultReservedSpace string          `json:",omitempty"`
+		DefaultMaxUsedSpace  string          `json:",omitempty"`
+		DefaultMinFreeSpace  string          `json:",omitempty"`
+
+		// Deprecated option is now equivalent to DefaultReservedSpace.
+		DefaultKeepStorage string `json:",omitempty"`
+	}
+
+	if err := json.Unmarshal(data, &xx); err != nil {
+		return err
+	}
+
+	x.Enabled = xx.Enabled
+	x.Policy = xx.Policy
+	x.DefaultReservedSpace = xx.DefaultReservedSpace
+	x.DefaultMaxUsedSpace = xx.DefaultMaxUsedSpace
+	x.DefaultMinFreeSpace = xx.DefaultMinFreeSpace
+	if x.DefaultReservedSpace == "" {
+		x.DefaultReservedSpace = xx.DefaultKeepStorage
+	}
+	return nil
 }
 
 // BuilderHistoryConfig contains history config for a buildkit builder

daemon/config/builder_test.go

@@ -12,6 +12,40 @@ import (
 
 func TestBuilderGC(t *testing.T) {
 	tempFile := fs.NewFile(t, "config", fs.WithContent(`{
+  "builder": {
+    "gc": {
+      "enabled": true,
+      "policy": [
+        {"reservedSpace": "10GB", "filter": ["unused-for=2200h"]},
+        {"reservedSpace": "50GB", "filter": {"unused-for": {"3300h": true}}},
+        {"reservedSpace": "100GB", "minFreeSpace": "10GB", "maxUsedSpace": "200GB", "all": true}
+      ]
+    }
+  }
+}`))
+	defer tempFile.Remove()
+	configFile := tempFile.Path()
+
+	cfg, err := MergeDaemonConfigurations(&Config{}, nil, configFile)
+	assert.NilError(t, err)
+	assert.Assert(t, cfg.Builder.GC.Enabled)
+	f1 := filters.NewArgs()
+	f1.Add("unused-for", "2200h")
+	f2 := filters.NewArgs()
+	f2.Add("unused-for", "3300h")
+	expectedPolicy := []BuilderGCRule{
+		{ReservedSpace: "10GB", Filter: BuilderGCFilter(f1)},
+		{ReservedSpace: "50GB", Filter: BuilderGCFilter(f2)}, /* parsed from deprecated form */
+		{ReservedSpace: "100GB", MinFreeSpace: "10GB", MaxUsedSpace: "200GB", All: true},
+	}
+	assert.DeepEqual(t, cfg.Builder.GC.Policy, expectedPolicy, cmp.AllowUnexported(BuilderGCFilter{}))
+	// double check to please the skeptics
+	assert.Assert(t, filters.Args(cfg.Builder.GC.Policy[0].Filter).UniqueExactMatch("unused-for", "2200h"))
+	assert.Assert(t, filters.Args(cfg.Builder.GC.Policy[1].Filter).UniqueExactMatch("unused-for", "3300h"))
+}
+
+func TestBuilderGC_DeprecatedKeepStorage(t *testing.T) {
+	tempFile := fs.NewFile(t, "config", fs.WithContent(`{
   "builder": {
     "gc": {
       "enabled": true,
@@ -34,9 +68,9 @@ func TestBuilderGC(t *testing.T) {
 	f2 := filters.NewArgs()
 	f2.Add("unused-for", "3300h")
 	expectedPolicy := []BuilderGCRule{
-		{KeepStorage: "10GB", Filter: BuilderGCFilter(f1)},
-		{KeepStorage: "50GB", Filter: BuilderGCFilter(f2)}, /* parsed from deprecated form */
-		{KeepStorage: "100GB", All: true},
+		{ReservedSpace: "10GB", Filter: BuilderGCFilter(f1)},
+		{ReservedSpace: "50GB", Filter: BuilderGCFilter(f2)}, /* parsed from deprecated form */
+		{ReservedSpace: "100GB", All: true},
 	}
 	assert.DeepEqual(t, cfg.Builder.GC.Policy, expectedPolicy, cmp.AllowUnexported(BuilderGCFilter{}))
 	// double check to please the skeptics
@@ -49,10 +83,10 @@ func TestBuilderGC(t *testing.T) {
 // missing a "=" separator). resulted in a panic during unmarshal.
 func TestBuilderGCFilterUnmarshal(t *testing.T) {
 	var cfg BuilderGCConfig
-	err := json.Unmarshal([]byte(`{"poliCy": [{"keepStorage": "10GB", "filter": ["unused-for2200h"]}]}`), &cfg)
+	err := json.Unmarshal([]byte(`{"poliCy": [{"reservedSpace": "10GB", "filter": ["unused-for2200h"]}]}`), &cfg)
 	assert.Check(t, err)
 	expectedPolicy := []BuilderGCRule{{
-		KeepStorage: "10GB", Filter: BuilderGCFilter(filters.NewArgs(filters.Arg("unused-for2200h", ""))),
+		ReservedSpace: "10GB", Filter: BuilderGCFilter(filters.NewArgs(filters.Arg("unused-for2200h", ""))),
 	}}
 	assert.DeepEqual(t, cfg.Policy, expectedPolicy, cmp.AllowUnexported(BuilderGCFilter{}))
 }

docs/api/version-history.md

@@ -71,6 +71,8 @@ keywords: "API, Docker, rcli, REST, documentation"
   `GET /debug/pprof/profile`, `GET /debug/pprof/symbol`, `GET /debug/pprof/trace`,
   `GET /debug/pprof/{name}`) are now also accessible through the versioned-API
   paths (`/v<API-version>/<endpoint>`).
+* `POST /build/prune` renames `keep-bytes` to `reserved-space` and now supports
+  additional prune parameters `max-used-space` and `min-free-space`.
 
 ## v1.47 API changes