api: add BuildCache.Parents for API >= v1.42

This field was added to replace the deprecated "Parent" field.

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

api/server/router/system/system_routes.go

@@ -174,6 +174,8 @@ func (s *systemRouter) getDiskUsage(ctx context.Context, w http.ResponseWriter,
 	if versions.LessThan(version, "1.42") {
 		for _, b := range buildCache {
 			builderSize += b.Size
+			// Parents field was added in API 1.42 to replace the Parent field.
+			b.Parents = nil
 		}
 	}
 	if versions.GreaterThanOrEqualTo(version, "1.42") {

api/swagger.yaml

@@ -2263,6 +2263,14 @@ definitions:
         type: "string"
         x-nullable: true
         example: ""
+      Parents:
+        description: |
+          List of parent build cache record IDs.
+        type: "array"
+        items:
+          type: "string"
+        x-nullable: true
+        example: ["hw53o5aio51xtltp5xjp8v7fx"]
       Type:
         type: "string"
         description: |
@@ -9068,6 +9076,7 @@ paths:
               BuildCache:
                 -
                   ID: "hw53o5aio51xtltp5xjp8v7fx"
+                  Parents: []
                   Type: "regular"
                   Description: "pulled from docker.io/library/debian@sha256:234cb88d3020898631af0ccbbcca9a66ae7306ecd30c9720690858c1b007d2a0"
                   InUse: false
@@ -9078,6 +9087,7 @@ paths:
                   UsageCount: 26
                 -
                   ID: "ndlpt0hhvkqcdfkputsk4cq9c"
+                  Parents: ["ndlpt0hhvkqcdfkputsk4cq9c"]
                   Type: "regular"
                   Description: "mount / from exec /bin/sh -c echo 'Binary::apt::APT::Keep-Downloaded-Packages \"true\";' > /etc/apt/apt.conf.d/keep-cache"
                   InUse: false

api/types/types.go

@@ -778,8 +778,10 @@ type BuildCache struct {
 	ID string
 	// Parent is the ID of the parent build cache record.
 	//
-	// Deprecated: deprecated in API v1.42 and up, as it was deprecated in BuildKit.
+	// Deprecated: deprecated in API v1.42 and up, as it was deprecated in BuildKit; use Parents instead.
 	Parent string `json:"Parent,omitempty"`
+	// Parents is the list of parent build cache record IDs.
+	Parents []string `json:" Parents,omitempty"`
 	// Type is the cache record type.
 	Type string
 	// Description is a description of the build-step that produced the build cache.

builder/builder-next/builder.go

@@ -130,6 +130,7 @@ func (b *Builder) DiskUsage(ctx context.Context) ([]*types.BuildCache, error) {
 		items = append(items, &types.BuildCache{
 			ID:          r.ID,
 			Parent:      r.Parent, //nolint:staticcheck // ignore SA1019 (Parent field is deprecated)
+			Parents:     r.Parents,
 			Type:        r.RecordType,
 			Description: r.Description,
 			InUse:       r.InUse,

docs/api/version-history.md

@@ -89,6 +89,8 @@ keywords: "API, Docker, rcli, REST, documentation"
   with information about the created volume.
 * The `BuildCache.Parent` field, as returned by `GET /system/df` is deprecated
   and is now omitted. API versions before v1.42 continue to include this field.
+* `GET /system/df` now includes a new `Parents` field, for "build-cache" records,
+  which contains a list of parent IDs for the build-cache record.
 * Volume information returned by `GET /volumes/{name}`, `GET /volumes` and
   `GET /system/df` can now contain a `ClusterVolume` if the volume is a cluster
   volume (requires the daemon to be a Swarm manager).