encoding/jsonschema: CRDs always define resources

The top level schema in a Kubernetes CRD is by definition
a resource, so should allow the usual metadata fields.

For #3907

Signed-off-by: Roger Peppe <[email protected]>
Change-Id: I8fac511d74f7008da751a9864ed9155780311ee1
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1214626
TryBot-Result: CUEcueckoo <[email protected]>
Reviewed-by: Daniel Martí <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>

Author: rogpeppe

encoding/jsonschema/decode.go

@@ -182,7 +182,11 @@ func (d *decoder) decode(v cue.Value) *ast.File {
 			// containing a field for each definition.
 			constraintAddDefinitions("schemas", defsRoot, root)
 		} else {
-			expr, state := root.schemaState(v, allTypes, nil)
+			expr, state := root.schemaState(v, allTypes, func(s *state) {
+				// We want the top level state to be treated as root even
+				// though it's some levels below the actual document top level.
+				s.isRoot = true
+			})
 			if state.allowedTypes == 0 {
 				root.errf(v, "constraints are not possible to satisfy")
 				return nil
@@ -887,6 +891,18 @@ func (s0 *state) schemaState(n cue.Value, types cue.Kind, init func(*state)) (ex
 			}
 			c.fn(key, value, s)
 		})
+		if s.schemaVersion == VersionKubernetesCRD && s.isRoot {
+			// The root of a CRD is always a resource, so treat it as if it contained
+			// the x-kubernetes-embedded-resource keyword
+			c := constraintMap["x-kubernetes-embedded-resource"]
+			if c.phase != pass {
+				continue
+			}
+			// Note: there is no field value for the embedded-resource keyword,
+			// but it's not actually used except for its position so passing
+			// the parent object should work fine.
+			c.fn("x-kubernetes-embedded-resource", n, s)
+		}
 	}
 	if s.id != nil {
 		// If there's an ID, it can be referred to.

encoding/jsonschema/testdata/txtar/crd_embeddedresource.txtar

@@ -55,6 +55,7 @@
     }
 }
 -- out/decode/extract --
+_embeddedResource
 apiVersion?: string
 kind?:       string
 metadata?: {}

encoding/jsonschema/testdata/txtar/crd_intorstring.txtar

@@ -29,4 +29,13 @@ spec:
             x-kubernetes-int-or-string: true
 
 -- out/decode/extract --
+_embeddedResource
 spec?: int | string
+
+_embeddedResource: {
+	apiVersion!: string
+	kind!:       string
+	metadata!: {
+		...
+	}
+}

encoding/jsonschema/testdata/txtar/crd_intorstring_with_anyof.txtar

@@ -35,4 +35,13 @@ spec:
               - type: string
 
 -- out/decode/extract --
+_embeddedResource
 spec?: matchN(>=1, [int, string]) & (int | string)
+
+_embeddedResource: {
+	apiVersion!: string
+	kind!:       string
+	metadata!: {
+		...
+	}
+}

encoding/jsonschema/testdata/txtar/crd_preserve_unknown.txtar

@@ -76,6 +76,7 @@
 }
 
 -- out/decode/extract --
+_embeddedResource
 alpha?: string
 beta?:  number
 preserving?: {
@@ -92,4 +93,12 @@ pruning?: {
 	}
 	pruning?: {}
 }
+
+_embeddedResource: {
+	apiVersion!: string
+	kind!:       string
+	metadata!: {
+		...
+	}
+}
 ...

encoding/jsonschema/testdata/txtar/crd_simple.txtar

@@ -30,6 +30,15 @@ spec:
             x-kubernetes-preserve-unknown-fields: true
 
 -- out/decode/extract --
+_embeddedResource
 spec?: {
 	...
 }
+
+_embeddedResource: {
+	apiVersion!: string
+	kind!:       string
+	metadata!: {
+		...
+	}
+}