Add BlockAttrs

plugins/shared/hclspec/dec.go

@@ -56,6 +56,9 @@ func decodeSpecBlock(spec *Spec, impliedName string) (hcldec.Spec, hcl.Diagnosti
 	case *Spec_BlockValue:
 		return decodeBlockSpec(spec.GetBlockValue(), impliedName)
 
+	case *Spec_BlockAttrs:
+		return decodeBlockAttrsSpec(spec.GetBlockAttrs(), impliedName)
+
 	case *Spec_BlockList:
 		return decodeBlockListSpec(spec.GetBlockList(), impliedName)
 
@@ -156,6 +159,38 @@ func decodeBlockSpec(block *Block, impliedName string) (hcldec.Spec, hcl.Diagnos
 	return spec, diags
 }
 
+func decodeBlockAttrsSpec(block *BlockAttrs, impliedName string) (hcldec.Spec, hcl.Diagnostics) {
+	// Convert the string type to an hcl.Expression
+	typeExpr, diags := hclsyntax.ParseExpression([]byte(block.GetType()), "proto", emptyPos)
+	if diags.HasErrors() {
+		return nil, diags
+	}
+
+	spec := &hcldec.BlockAttrsSpec{
+		TypeName: impliedName,
+		Required: block.GetRequired(),
+	}
+
+	if n := block.GetName(); n != "" {
+		spec.TypeName = n
+	}
+
+	var typeDiags hcl.Diagnostics
+	spec.ElementType, typeDiags = evalTypeExpr(typeExpr)
+	diags = append(diags, typeDiags...)
+
+	if spec.TypeName == "" {
+		diags = append(diags, &hcl.Diagnostic{
+			Severity: hcl.DiagError,
+			Summary:  "Missing name in block_attrs spec",
+			Detail:   "The name attribute is required, to specify the block attr name that is expected in an input HCL file.",
+		})
+		return nil, diags
+	}
+
+	return spec, diags
+}
+
 func decodeBlockListSpec(block *BlockList, impliedName string) (hcldec.Spec, hcl.Diagnostics) {
 	spec := &hcldec.BlockListSpec{
 		TypeName: impliedName,

plugins/shared/hclspec/dec_test.go

@@ -281,6 +281,44 @@ func TestDec_Convert_Block(t *testing.T) {
 	testSpecConversions(t, tests)
 }
 
+func TestDec_Convert_BlockAttrs(t *testing.T) {
+	t.Parallel()
+
+	tests := []testConversions{
+		{
+			Name: "block attr",
+			Input: &Spec{
+				Block: &Spec_BlockAttrs{
+					BlockAttrs: &BlockAttrs{
+						Name:     "test",
+						Type:     "string",
+						Required: true,
+					},
+				},
+			},
+			Expected: &hcldec.BlockAttrsSpec{
+				TypeName:    "test",
+				ElementType: cty.String,
+				Required:    true,
+			},
+		},
+		{
+			Name: "block list no name",
+			Input: &Spec{
+				Block: &Spec_BlockAttrs{
+					BlockAttrs: &BlockAttrs{
+						Type:     "string",
+						Required: true,
+					},
+				},
+			},
+			ExpectedError: "Missing name in block_attrs spec",
+		},
+	}
+
+	testSpecConversions(t, tests)
+}
+
 func TestDec_Convert_BlockList(t *testing.T) {
 	t.Parallel()
 

plugins/shared/hclspec/hcl_spec.pb.go

@@ -1,5 +1,5 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
-// source: github.com/hashicorp/nomad/plugins/shared/hclspec/hcl_spec.proto
+// source: hcl_spec.proto
 
 package hclspec
 
@@ -78,6 +78,7 @@ type Spec struct {
 	//	*Spec_Array
 	//	*Spec_Attr
 	//	*Spec_BlockValue
+	//	*Spec_BlockAttrs
 	//	*Spec_BlockList
 	//	*Spec_BlockSet
 	//	*Spec_BlockMap
@@ -93,7 +94,7 @@ func (m *Spec) Reset()         { *m = Spec{} }
 func (m *Spec) String() string { return proto.CompactTextString(m) }
 func (*Spec) ProtoMessage()    {}
 func (*Spec) Descriptor() ([]byte, []int) {
-	return fileDescriptor_hcl_spec_2b7d8262531848bd, []int{0}
+	return fileDescriptor_hcl_spec_b17a3e0d58741859, []int{0}
 }
 func (m *Spec) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Spec.Unmarshal(m, b)
@@ -133,24 +134,28 @@ type Spec_BlockValue struct {
 	BlockValue *Block `protobuf:"bytes,4,opt,name=block_value,json=blockValue,proto3,oneof"`
 }
 
+type Spec_BlockAttrs struct {
+	BlockAttrs *BlockAttrs `protobuf:"bytes,5,opt,name=block_attrs,json=blockAttrs,proto3,oneof"`
+}
+
 type Spec_BlockList struct {
-	BlockList *BlockList `protobuf:"bytes,5,opt,name=block_list,json=blockList,proto3,oneof"`
+	BlockList *BlockList `protobuf:"bytes,6,opt,name=block_list,json=blockList,proto3,oneof"`
 }
 
 type Spec_BlockSet struct {
-	BlockSet *BlockSet `protobuf:"bytes,6,opt,name=block_set,json=blockSet,proto3,oneof"`
+	BlockSet *BlockSet `protobuf:"bytes,7,opt,name=block_set,json=blockSet,proto3,oneof"`
 }
 
 type Spec_BlockMap struct {
-	BlockMap *BlockMap `protobuf:"bytes,7,opt,name=block_map,json=blockMap,proto3,oneof"`
+	BlockMap *BlockMap `protobuf:"bytes,8,opt,name=block_map,json=blockMap,proto3,oneof"`
 }
 
 type Spec_Default struct {
-	Default *Default `protobuf:"bytes,8,opt,name=default,proto3,oneof"`
+	Default *Default `protobuf:"bytes,9,opt,name=default,proto3,oneof"`
 }
 
 type Spec_Literal struct {
-	Literal *Literal `protobuf:"bytes,9,opt,name=literal,proto3,oneof"`
+	Literal *Literal `protobuf:"bytes,10,opt,name=literal,proto3,oneof"`
 }
 
 func (*Spec_Object) isSpec_Block() {}
@@ -161,6 +166,8 @@ func (*Spec_Attr) isSpec_Block() {}
 
 func (*Spec_BlockValue) isSpec_Block() {}
 
+func (*Spec_BlockAttrs) isSpec_Block() {}
+
 func (*Spec_BlockList) isSpec_Block() {}
 
 func (*Spec_BlockSet) isSpec_Block() {}
@@ -206,6 +213,13 @@ func (m *Spec) GetBlockValue() *Block {
 	return nil
 }
 
+func (m *Spec) GetBlockAttrs() *BlockAttrs {
+	if x, ok := m.GetBlock().(*Spec_BlockAttrs); ok {
+		return x.BlockAttrs
+	}
+	return nil
+}
+
 func (m *Spec) GetBlockList() *BlockList {
 	if x, ok := m.GetBlock().(*Spec_BlockList); ok {
 		return x.BlockList
@@ -248,6 +262,7 @@ func (*Spec) XXX_OneofFuncs() (func(msg proto.Message, b *proto.Buffer) error, f
 		(*Spec_Array)(nil),
 		(*Spec_Attr)(nil),
 		(*Spec_BlockValue)(nil),
+		(*Spec_BlockAttrs)(nil),
 		(*Spec_BlockList)(nil),
 		(*Spec_BlockSet)(nil),
 		(*Spec_BlockMap)(nil),
@@ -280,28 +295,33 @@ func _Spec_OneofMarshaler(msg proto.Message, b *proto.Buffer) error {
 		if err := b.EncodeMessage(x.BlockValue); err != nil {
 			return err
 		}
-	case *Spec_BlockList:
+	case *Spec_BlockAttrs:
 		b.EncodeVarint(5<<3 | proto.WireBytes)
+		if err := b.EncodeMessage(x.BlockAttrs); err != nil {
+			return err
+		}
+	case *Spec_BlockList:
+		b.EncodeVarint(6<<3 | proto.WireBytes)
 		if err := b.EncodeMessage(x.BlockList); err != nil {
 			return err
 		}
 	case *Spec_BlockSet:
-		b.EncodeVarint(6<<3 | proto.WireBytes)
+		b.EncodeVarint(7<<3 | proto.WireBytes)
 		if err := b.EncodeMessage(x.BlockSet); err != nil {
 			return err
 		}
 	case *Spec_BlockMap:
-		b.EncodeVarint(7<<3 | proto.WireBytes)
+		b.EncodeVarint(8<<3 | proto.WireBytes)
 		if err := b.EncodeMessage(x.BlockMap); err != nil {
 			return err
 		}
 	case *Spec_Default:
-		b.EncodeVarint(8<<3 | proto.WireBytes)
+		b.EncodeVarint(9<<3 | proto.WireBytes)
 		if err := b.EncodeMessage(x.Default); err != nil {
 			return err
 		}
 	case *Spec_Literal:
-		b.EncodeVarint(9<<3 | proto.WireBytes)
+		b.EncodeVarint(10<<3 | proto.WireBytes)
 		if err := b.EncodeMessage(x.Literal); err != nil {
 			return err
 		}
@@ -347,7 +367,15 @@ func _Spec_OneofUnmarshaler(msg proto.Message, tag, wire int, b *proto.Buffer) (
 		err := b.DecodeMessage(msg)
 		m.Block = &Spec_BlockValue{msg}
 		return true, err
-	case 5: // block.block_list
+	case 5: // block.block_attrs
+		if wire != proto.WireBytes {
+			return true, proto.ErrInternalBadWireType
+		}
+		msg := new(BlockAttrs)
+		err := b.DecodeMessage(msg)
+		m.Block = &Spec_BlockAttrs{msg}
+		return true, err
+	case 6: // block.block_list
 		if wire != proto.WireBytes {
 			return true, proto.ErrInternalBadWireType
 		}
@@ -355,7 +383,7 @@ func _Spec_OneofUnmarshaler(msg proto.Message, tag, wire int, b *proto.Buffer) (
 		err := b.DecodeMessage(msg)
 		m.Block = &Spec_BlockList{msg}
 		return true, err
-	case 6: // block.block_set
+	case 7: // block.block_set
 		if wire != proto.WireBytes {
 			return true, proto.ErrInternalBadWireType
 		}
@@ -363,7 +391,7 @@ func _Spec_OneofUnmarshaler(msg proto.Message, tag, wire int, b *proto.Buffer) (
 		err := b.DecodeMessage(msg)
 		m.Block = &Spec_BlockSet{msg}
 		return true, err
-	case 7: // block.block_map
+	case 8: // block.block_map
 		if wire != proto.WireBytes {
 			return true, proto.ErrInternalBadWireType
 		}
@@ -371,7 +399,7 @@ func _Spec_OneofUnmarshaler(msg proto.Message, tag, wire int, b *proto.Buffer) (
 		err := b.DecodeMessage(msg)
 		m.Block = &Spec_BlockMap{msg}
 		return true, err
-	case 8: // block.default
+	case 9: // block.default
 		if wire != proto.WireBytes {
 			return true, proto.ErrInternalBadWireType
 		}
@@ -379,7 +407,7 @@ func _Spec_OneofUnmarshaler(msg proto.Message, tag, wire int, b *proto.Buffer) (
 		err := b.DecodeMessage(msg)
 		m.Block = &Spec_Default{msg}
 		return true, err
-	case 9: // block.literal
+	case 10: // block.literal
 		if wire != proto.WireBytes {
 			return true, proto.ErrInternalBadWireType
 		}
@@ -416,6 +444,11 @@ func _Spec_OneofSizer(msg proto.Message) (n int) {
 		n += 1 // tag and wire
 		n += proto.SizeVarint(uint64(s))
 		n += s
+	case *Spec_BlockAttrs:
+		s := proto.Size(x.BlockAttrs)
+		n += 1 // tag and wire
+		n += proto.SizeVarint(uint64(s))
+		n += s
 	case *Spec_BlockList:
 		s := proto.Size(x.BlockList)
 		n += 1 // tag and wire
@@ -489,7 +522,7 @@ func (m *Attr) Reset()         { *m = Attr{} }
 func (m *Attr) String() string { return proto.CompactTextString(m) }
 func (*Attr) ProtoMessage()    {}
 func (*Attr) Descriptor() ([]byte, []int) {
-	return fileDescriptor_hcl_spec_2b7d8262531848bd, []int{1}
+	return fileDescriptor_hcl_spec_b17a3e0d58741859, []int{1}
 }
 func (m *Attr) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Attr.Unmarshal(m, b)
@@ -578,7 +611,7 @@ func (m *Block) Reset()         { *m = Block{} }
 func (m *Block) String() string { return proto.CompactTextString(m) }
 func (*Block) ProtoMessage()    {}
 func (*Block) Descriptor() ([]byte, []int) {
-	return fileDescriptor_hcl_spec_2b7d8262531848bd, []int{2}
+	return fileDescriptor_hcl_spec_b17a3e0d58741859, []int{2}
 }
 func (m *Block) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Block.Unmarshal(m, b)
@@ -619,6 +652,92 @@ func (m *Block) GetNested() *Spec {
 	return nil
 }
 
+//
+// The BlockAttrs spec type is similar to an Attr spec block of a map type,
+// but it produces a map from the attributes of a block rather than from an
+// attribute's expression.
+//
+// ```hcl
+// BlockAttrs {
+// name     = "variables"
+// type     = string
+// required = false
+// }
+// ```
+//
+// This allows a map with user-defined keys to be produced within block syntax,
+// but due to the constraints of that syntax it also means that the user will
+// be unable to dynamically-generate either individual key names using key
+// expressions or the entire map value using a `for` expression.
+//
+// `BlockAttrs` spec blocks accept the following arguments:
+//
+// `name` (required) - The block type name to expect within the HCL
+// input file. This may be omitted when a default name selector is created
+// by a parent `object` spec, if the input block type name should match the
+// output JSON object property name.
+//
+// `type` (required) - The value type to require for each of the
+// attributes within a matched block. The resulting value will be a JSON
+// object whose property values are of this type.
+//
+// `required` (optional) - If `true`, an error will be produced if a block
+// of the given type is not present. If `false` -- the default -- an absent
+// block will be indicated by producing `null`.
+type BlockAttrs struct {
+	Name                 string   `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
+	Type                 string   `protobuf:"bytes,2,opt,name=type,proto3" json:"type,omitempty"`
+	Required             bool     `protobuf:"varint,3,opt,name=required,proto3" json:"required,omitempty"`
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *BlockAttrs) Reset()         { *m = BlockAttrs{} }
+func (m *BlockAttrs) String() string { return proto.CompactTextString(m) }
+func (*BlockAttrs) ProtoMessage()    {}
+func (*BlockAttrs) Descriptor() ([]byte, []int) {
+	return fileDescriptor_hcl_spec_b17a3e0d58741859, []int{3}
+}
+func (m *BlockAttrs) XXX_Unmarshal(b []byte) error {
+	return xxx_messageInfo_BlockAttrs.Unmarshal(m, b)
+}
+func (m *BlockAttrs) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	return xxx_messageInfo_BlockAttrs.Marshal(b, m, deterministic)
+}
+func (dst *BlockAttrs) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_BlockAttrs.Merge(dst, src)
+}
+func (m *BlockAttrs) XXX_Size() int {
+	return xxx_messageInfo_BlockAttrs.Size(m)
+}
+func (m *BlockAttrs) XXX_DiscardUnknown() {
+	xxx_messageInfo_BlockAttrs.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_BlockAttrs proto.InternalMessageInfo
+
+func (m *BlockAttrs) GetName() string {
+	if m != nil {
+		return m.Name
+	}
+	return ""
+}
+
+func (m *BlockAttrs) GetType() string {
+	if m != nil {
+		return m.Type
+	}
+	return ""
+}
+
+func (m *BlockAttrs) GetRequired() bool {
+	if m != nil {
+		return m.Required
+	}
+	return false
+}
+
 // BlockList spec type is similar to `Block`, but it accepts zero or
 // more blocks of a specified type rather than requiring zero or one. The
 // result is a JSON array with one entry per block of the given type.
@@ -673,7 +792,7 @@ func (m *BlockList) Reset()         { *m = BlockList{} }
 func (m *BlockList) String() string { return proto.CompactTextString(m) }
 func (*BlockList) ProtoMessage()    {}
 func (*BlockList) Descriptor() ([]byte, []int) {
-	return fileDescriptor_hcl_spec_2b7d8262531848bd, []int{3}
+	return fileDescriptor_hcl_spec_b17a3e0d58741859, []int{4}
 }
 func (m *BlockList) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_BlockList.Unmarshal(m, b)
@@ -756,7 +875,7 @@ func (m *BlockSet) Reset()         { *m = BlockSet{} }
 func (m *BlockSet) String() string { return proto.CompactTextString(m) }
 func (*BlockSet) ProtoMessage()    {}
 func (*BlockSet) Descriptor() ([]byte, []int) {
-	return fileDescriptor_hcl_spec_2b7d8262531848bd, []int{4}
+	return fileDescriptor_hcl_spec_b17a3e0d58741859, []int{5}
 }
 func (m *BlockSet) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_BlockSet.Unmarshal(m, b)
@@ -855,7 +974,7 @@ func (m *BlockMap) Reset()         { *m = BlockMap{} }
 func (m *BlockMap) String() string { return proto.CompactTextString(m) }
 func (*BlockMap) ProtoMessage()    {}
 func (*BlockMap) Descriptor() ([]byte, []int) {
-	return fileDescriptor_hcl_spec_2b7d8262531848bd, []int{5}
+	return fileDescriptor_hcl_spec_b17a3e0d58741859, []int{6}
 }
 func (m *BlockMap) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_BlockMap.Unmarshal(m, b)
@@ -925,7 +1044,7 @@ func (m *Literal) Reset()         { *m = Literal{} }
 func (m *Literal) String() string { return proto.CompactTextString(m) }
 func (*Literal) ProtoMessage()    {}
 func (*Literal) Descriptor() ([]byte, []int) {
-	return fileDescriptor_hcl_spec_2b7d8262531848bd, []int{6}
+	return fileDescriptor_hcl_spec_b17a3e0d58741859, []int{7}
 }
 func (m *Literal) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Literal.Unmarshal(m, b)
@@ -989,7 +1108,7 @@ func (m *Default) Reset()         { *m = Default{} }
 func (m *Default) String() string { return proto.CompactTextString(m) }
 func (*Default) ProtoMessage()    {}
 func (*Default) Descriptor() ([]byte, []int) {
-	return fileDescriptor_hcl_spec_2b7d8262531848bd, []int{7}
+	return fileDescriptor_hcl_spec_b17a3e0d58741859, []int{8}
 }
 func (m *Default) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Default.Unmarshal(m, b)
@@ -1063,7 +1182,7 @@ func (m *Object) Reset()         { *m = Object{} }
 func (m *Object) String() string { return proto.CompactTextString(m) }
 func (*Object) ProtoMessage()    {}
 func (*Object) Descriptor() ([]byte, []int) {
-	return fileDescriptor_hcl_spec_2b7d8262531848bd, []int{8}
+	return fileDescriptor_hcl_spec_b17a3e0d58741859, []int{9}
 }
 func (m *Object) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Object.Unmarshal(m, b)
@@ -1119,7 +1238,7 @@ func (m *Array) Reset()         { *m = Array{} }
 func (m *Array) String() string { return proto.CompactTextString(m) }
 func (*Array) ProtoMessage()    {}
 func (*Array) Descriptor() ([]byte, []int) {
-	return fileDescriptor_hcl_spec_2b7d8262531848bd, []int{9}
+	return fileDescriptor_hcl_spec_b17a3e0d58741859, []int{10}
 }
 func (m *Array) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Array.Unmarshal(m, b)
@@ -1150,6 +1269,7 @@ func init() {
 	proto.RegisterType((*Spec)(nil), "hashicorp.nomad.plugins.shared.hclspec.Spec")
 	proto.RegisterType((*Attr)(nil), "hashicorp.nomad.plugins.shared.hclspec.Attr")
 	proto.RegisterType((*Block)(nil), "hashicorp.nomad.plugins.shared.hclspec.Block")
+	proto.RegisterType((*BlockAttrs)(nil), "hashicorp.nomad.plugins.shared.hclspec.BlockAttrs")
 	proto.RegisterType((*BlockList)(nil), "hashicorp.nomad.plugins.shared.hclspec.BlockList")
 	proto.RegisterType((*BlockSet)(nil), "hashicorp.nomad.plugins.shared.hclspec.BlockSet")
 	proto.RegisterType((*BlockMap)(nil), "hashicorp.nomad.plugins.shared.hclspec.BlockMap")
@@ -1160,49 +1280,47 @@ func init() {
 	proto.RegisterType((*Array)(nil), "hashicorp.nomad.plugins.shared.hclspec.Array")
 }
 
-func init() {
+func init() { proto.RegisterFile("hcl_spec.proto", fileDescriptor_hcl_spec_b17a3e0d58741859) }
-	proto.RegisterFile("github.com/hashicorp/nomad/plugins/shared/hclspec/hcl_spec.proto", fileDescriptor_hcl_spec_2b7d8262531848bd)
-}
 
-var fileDescriptor_hcl_spec_2b7d8262531848bd = []byte{
+var fileDescriptor_hcl_spec_b17a3e0d58741859 = []byte{
-	// 612 bytes of a gzipped FileDescriptorProto
+	// 617 bytes of a gzipped FileDescriptorProto
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+	0xd1, 0xda, 0x59, 0x88, 0x89, 0xbf, 0xd8, 0xdd, 0xa0, 0x46, 0x82, 0x07, 0xe1, 0x00, 0x3c, 0x15,
-	0xc3, 0x1b, 0xf0, 0x3e, 0xc8, 0x97, 0x4c, 0x0b, 0xea, 0x62, 0x32, 0xb0, 0x60, 0x35, 0x3e, 0x3e,
+	0xef, 0x83, 0xf6, 0xc3, 0x49, 0x41, 0x39, 0xc4, 0xa1, 0x07, 0x6e, 0x3b, 0x3b, 0xf9, 0xff, 0x3c,
-	0xfa, 0xbe, 0x39, 0xb1, 0x8f, 0x6d, 0x78, 0x7a, 0xc6, 0xc4, 0xa2, 0xcb, 0xe2, 0xbc, 0x2e, 0x93,
+	0xb3, 0x3b, 0xb3, 0x13, 0xb8, 0x36, 0xcd, 0x8a, 0x31, 0x6f, 0x68, 0x16, 0x37, 0xac, 0x16, 0x35,
-	0x05, 0x69, 0x17, 0x2c, 0xaf, 0x79, 0x93, 0x54, 0x75, 0x49, 0xe6, 0x49, 0x53, 0x74, 0x67, 0xac,
+	0xba, 0x3b, 0x25, 0x7c, 0x9a, 0x67, 0x35, 0x6b, 0xe2, 0xaa, 0x2e, 0xc9, 0x24, 0x6e, 0x8a, 0xf9,
-	0x6a, 0x93, 0x76, 0x41, 0x38, 0x9d, 0x27, 0x8b, 0xbc, 0x68, 0x1b, 0x9a, 0xcb, 0xdf, 0x99, 0x1c,
+	0x87, 0xbc, 0xe2, 0x31, 0x9f, 0x12, 0x46, 0x27, 0xf1, 0x34, 0x2b, 0xe4, 0xaf, 0xa3, 0xef, 0x2e,
-	0xc4, 0x0d, 0xaf, 0x45, 0x8d, 0xee, 0xac, 0xb0, 0x58, 0x61, 0xb1, 0xc1, 0x62, 0x8d, 0xc5, 0x06,
+	0xd8, 0xe7, 0x0d, 0xcd, 0x50, 0x02, 0x6e, 0x9d, 0x7e, 0xa4, 0x99, 0x08, 0xad, 0x3d, 0x6b, 0x7f,
-	0x8b, 0xbe, 0x3b, 0x60, 0x9f, 0x36, 0x34, 0x47, 0x29, 0xb8, 0x75, 0xf6, 0x9e, 0xe6, 0x22, 0xb4,
+	0xe7, 0x20, 0x8e, 0x37, 0x23, 0xc4, 0xa7, 0x4a, 0x95, 0xf4, 0xb0, 0xd1, 0xa3, 0x63, 0x70, 0x08,
-	0x76, 0xac, 0xdd, 0xad, 0xbd, 0x38, 0x5e, 0xcf, 0x10, 0x9f, 0x28, 0x2a, 0x1d, 0x61, 0xc3, 0xa3,
+	0x63, 0x64, 0x11, 0xf6, 0x15, 0xe8, 0xfe, 0xa6, 0xa0, 0x43, 0x29, 0x4a, 0x7a, 0x58, 0xab, 0xd1,
-	0x43, 0x70, 0x08, 0xe7, 0x64, 0x19, 0x8e, 0x95, 0xe8, 0xde, 0xba, 0xa2, 0x7d, 0x09, 0xa5, 0x23,
+	0x10, 0xec, 0x43, 0x21, 0x58, 0x38, 0x50, 0x94, 0x7b, 0x1b, 0x53, 0x84, 0x60, 0x49, 0x0f, 0x2b,
-	0xac, 0x69, 0x34, 0x05, 0x7b, 0x5f, 0x08, 0x1e, 0x4e, 0x94, 0xe5, 0xee, 0xda, 0x16, 0x21, 0x78,
+	0x2d, 0x3a, 0x83, 0x9d, 0xb4, 0xa8, 0xb3, 0xd9, 0xf8, 0x33, 0x29, 0xe6, 0x34, 0xb4, 0xbb, 0x05,
-	0x3a, 0xc2, 0x8a, 0x45, 0xaf, 0x60, 0x2b, 0x2b, 0xea, 0xfc, 0x7c, 0xf6, 0x91, 0x14, 0x1d, 0x0d,
+	0x34, 0x94, 0xd2, 0xa4, 0x87, 0x41, 0x31, 0xde, 0x48, 0x04, 0x7a, 0xdd, 0x12, 0x89, 0x10, 0x8c,
-	0xed, 0x61, 0x05, 0x4d, 0x25, 0x9a, 0x8e, 0x30, 0x28, 0xc7, 0x6b, 0xa9, 0x40, 0x18, 0x74, 0x34,
+	0x87, 0x8e, 0x22, 0x1e, 0x74, 0x22, 0xca, 0xc8, 0xf8, 0x12, 0xab, 0x2c, 0x84, 0x41, 0x5b, 0xe3,
-	0x2b, 0x58, 0x2b, 0x42, 0x47, 0x09, 0x1f, 0x0c, 0x12, 0x1e, 0xb1, 0x56, 0xae, 0x56, 0x90, 0xf5,
+	0x22, 0xe7, 0x22, 0x74, 0x15, 0xf5, 0x51, 0x27, 0xea, 0x49, 0xce, 0xe5, 0x25, 0x04, 0x69, 0x6b,
-	0x01, 0x3a, 0x01, 0x1d, 0xcc, 0x5a, 0x2a, 0x42, 0x57, 0x29, 0xef, 0x0f, 0x52, 0x9e, 0x52, 0x69,
+	0xa0, 0x53, 0xd0, 0xc6, 0x98, 0x53, 0x11, 0x7a, 0x0a, 0xf9, 0xb0, 0x13, 0xf2, 0x9c, 0x4a, 0xa2,
-	0xf4, 0x33, 0x33, 0xbe, 0x14, 0x96, 0xa4, 0x09, 0xbd, 0x0d, 0x84, 0xc7, 0xa4, 0x59, 0x09, 0x8f,
+	0x9f, 0x9a, 0xf5, 0x0a, 0x58, 0x92, 0x26, 0xf4, 0xb7, 0x00, 0x8e, 0x48, 0xb3, 0x04, 0x8e, 0x48,
-	0x49, 0x83, 0x5e, 0x82, 0x37, 0xa7, 0xef, 0x48, 0x57, 0x88, 0xd0, 0x57, 0xba, 0x64, 0x5d, 0xdd,
+	0x83, 0x5e, 0x81, 0x37, 0xa1, 0xef, 0xc9, 0xbc, 0x10, 0x61, 0xa0, 0x70, 0x0f, 0x36, 0xc5, 0x1d,
-	0x81, 0xc6, 0xd2, 0x11, 0xee, 0x0d, 0x52, 0x56, 0x30, 0x41, 0x39, 0x29, 0xc2, 0x60, 0x98, 0xec,
+	0x69, 0x59, 0xd2, 0xc3, 0x2d, 0x41, 0xc2, 0x8a, 0x5c, 0x50, 0x46, 0x8a, 0x10, 0xba, 0xc1, 0x4e,
-	0x48, 0x63, 0x52, 0x66, 0x0c, 0x53, 0x0f, 0x1c, 0x55, 0x65, 0xf4, 0x42, 0xb7, 0x0b, 0x42, 0x60,
+	0xb4, 0x4c, 0xc2, 0x0c, 0x61, 0xe8, 0x81, 0xa3, 0xa2, 0x8c, 0x5e, 0xea, 0x2a, 0x44, 0x08, 0xec,
-	0x57, 0xa4, 0xa4, 0xaa, 0x8b, 0x03, 0xac, 0xc6, 0x72, 0x4e, 0x2c, 0x1b, 0xaa, 0x1a, 0x32, 0xc0,
+	0x8a, 0x94, 0x54, 0x35, 0x47, 0x80, 0xd5, 0x5a, 0xee, 0x89, 0x45, 0x43, 0x55, 0x9d, 0x07, 0x58,
-	0x6a, 0x8c, 0xb6, 0xc1, 0xe7, 0xf4, 0x43, 0xc7, 0x38, 0x9d, 0xab, 0x16, 0xf3, 0xf1, 0x2a, 0x8e,
+	0xad, 0xd1, 0x2e, 0xf8, 0x8c, 0x7e, 0x9a, 0xe7, 0x8c, 0x4e, 0x54, 0xe5, 0xfa, 0x78, 0x69, 0x47,
-	0x3e, 0x83, 0xa3, 0x96, 0xe1, 0x5a, 0xd9, 0x55, 0x70, 0xfc, 0x2b, 0x88, 0x0e, 0xc0, 0xad, 0x68,
+	0x5f, 0xc1, 0x51, 0xc7, 0xb0, 0x16, 0x76, 0x59, 0xd8, 0xff, 0x53, 0x88, 0x8e, 0xc0, 0xad, 0x28,
-	0x2b, 0x8c, 0x72, 0x40, 0xd7, 0xca, 0x23, 0x88, 0x0d, 0x1b, 0x7d, 0xb3, 0x20, 0x58, 0xb5, 0xca,
+	0x17, 0x06, 0xd9, 0xa1, 0x19, 0x64, 0x67, 0x63, 0xa3, 0x8d, 0xce, 0x00, 0x56, 0xf5, 0x77, 0x25,
-	0xb5, 0x35, 0xdc, 0x82, 0xa0, 0x64, 0xd5, 0x8c, 0x09, 0x5a, 0xb6, 0xaa, 0x08, 0x1b, 0xfb, 0x25,
+	0x09, 0xfd, 0xb4, 0x20, 0x58, 0x16, 0xdf, 0x5a, 0xe2, 0x6d, 0x08, 0xca, 0xbc, 0x1a, 0xe7, 0x82,
-	0xab, 0x9e, 0xcb, 0x58, 0x25, 0xc9, 0x85, 0x49, 0x4e, 0x4c, 0x92, 0x5c, 0xe8, 0xe4, 0x65, 0x85,
+	0x96, 0x5c, 0x61, 0x6d, 0xec, 0x97, 0x79, 0xf5, 0x42, 0xda, 0xca, 0x49, 0x2e, 0x8c, 0x73, 0x60,
-	0xf6, 0x1f, 0x54, 0xf8, 0xd5, 0x02, 0xbf, 0xef, 0xbc, 0x7f, 0xb2, 0xc0, 0x4f, 0xa6, 0x3e, 0xd9,
+	0x9c, 0xe4, 0x42, 0x3b, 0x57, 0x39, 0xdb, 0xff, 0x90, 0xf3, 0x0f, 0x0b, 0xfc, 0xb6, 0x96, 0xff,
-	0xbc, 0xd7, 0xd5, 0x77, 0x13, 0xdc, 0x82, 0x64, 0xb4, 0x90, 0xc5, 0x4d, 0x76, 0x03, 0x6c, 0xa2,
+	0xcb, 0x00, 0xbf, 0x98, 0xf8, 0x64, 0x3b, 0xac, 0x8b, 0xef, 0x16, 0xb8, 0x05, 0x49, 0x69, 0x21,
-	0xbf, 0xb4, 0x81, 0xb7, 0xc1, 0x33, 0xad, 0x8a, 0x6e, 0x80, 0xa3, 0xef, 0x1e, 0xfd, 0xef, 0x3a,
+	0x83, 0x1b, 0xec, 0x07, 0xd8, 0x58, 0x57, 0x54, 0x12, 0x77, 0xc0, 0x33, 0xc5, 0x8f, 0x6e, 0x82,
-	0x88, 0xbe, 0x58, 0xe0, 0x99, 0x93, 0x81, 0x9e, 0x81, 0xd7, 0x70, 0x56, 0x12, 0xbe, 0x34, 0x37,
+	0xa3, 0x1f, 0x49, 0xfd, 0x75, 0x6d, 0x44, 0xdf, 0x2c, 0xf0, 0x4c, 0xaf, 0xa1, 0xe7, 0xe0, 0x35,
-	0xef, 0xb0, 0xff, 0xec, 0x61, 0xe9, 0xe9, 0xcf, 0xe8, 0x78, 0x13, 0x8f, 0x81, 0xa3, 0x1f, 0x16,
+	0x2c, 0x2f, 0x09, 0x5b, 0x98, 0x11, 0xd1, 0xed, 0x9b, 0xad, 0x58, 0x72, 0xda, 0xae, 0xef, 0x6f,
-	0xb8, 0xfa, 0x4e, 0x47, 0x6f, 0x01, 0x88, 0x10, 0x9c, 0x65, 0x9d, 0xa0, 0x6d, 0x68, 0xed, 0x4c,
+	0xc3, 0x31, 0xe2, 0xe8, 0x97, 0x05, 0xae, 0x1e, 0x3e, 0xe8, 0x1d, 0x80, 0x7c, 0x8f, 0xf3, 0x74,
-	0x76, 0xb7, 0xf6, 0x9e, 0x0c, 0x7b, 0x17, 0xd4, 0x7d, 0xac, 0x05, 0x87, 0x95, 0xe0, 0x4b, 0x7c,
+	0x2e, 0x28, 0x0f, 0xad, 0xbd, 0xc1, 0xfe, 0xce, 0xc1, 0xb3, 0x6e, 0x03, 0x4c, 0x0d, 0x0e, 0x0d,
-	0xc5, 0xb8, 0x7d, 0x0e, 0xff, 0xfd, 0x96, 0x46, 0xff, 0xc3, 0xe4, 0x9c, 0x2e, 0xcd, 0x6a, 0xc9,
+	0x38, 0xae, 0x04, 0x5b, 0xe0, 0x4b, 0xc4, 0xdd, 0x19, 0x5c, 0xff, 0xcb, 0x8d, 0x6e, 0xc0, 0x60,
-	0x21, 0x9a, 0xf6, 0x2b, 0xb8, 0xc9, 0x57, 0x69, 0xf4, 0xf1, 0xf8, 0x91, 0x15, 0x1d, 0x83, 0xa3,
+	0x46, 0x17, 0xe6, 0xb4, 0xe4, 0x12, 0x0d, 0xdb, 0x13, 0xdc, 0x26, 0x2b, 0x2d, 0x7d, 0xda, 0x7f,
-	0x5e, 0x18, 0xb9, 0xc7, 0x6a, 0xb6, 0xff, 0xa2, 0x81, 0x7b, 0xac, 0xd9, 0x69, 0xf0, 0xc6, 0x33,
+	0x62, 0x45, 0x23, 0x70, 0xd4, 0x28, 0x94, 0x77, 0xac, 0x76, 0xdb, 0x8c, 0x3a, 0xde, 0xb1, 0xd6,
-	0xf3, 0x99, 0xab, 0x9e, 0xdc, 0x87, 0x3f, 0x03, 0x00, 0x00, 0xff, 0xff, 0x4f, 0x2c, 0x98, 0x6b,
+	0x0e, 0x83, 0xb7, 0x9e, 0xd9, 0x4f, 0x5d, 0xf5, 0xdf, 0xe0, 0xf1, 0xef, 0x00, 0x00, 0x00, 0xff,
-	0xb6, 0x07, 0x00, 0x00,
+	0xff, 0x18, 0x16, 0x39, 0xa4, 0x2d, 0x08, 0x00, 0x00,
 }

plugins/shared/hclspec/hcl_spec.proto

@@ -62,11 +62,12 @@ message Spec {
     Array array = 2;
     Attr Attr = 3;
     Block block_value = 4;
-    BlockList block_list = 5;
+    BlockAttrs block_attrs = 5;
-    BlockSet block_set = 6;
+    BlockList block_list = 6;
-    BlockMap block_map = 7;
+    BlockSet block_set = 7;
-    Default default = 8;
+    BlockMap block_map = 8;
-    Literal literal = 9;
+    Default default = 9;
+    Literal literal = 10;
   }
 }
 
@@ -147,6 +148,45 @@ message Block {
  Spec nested = 3;
 }
 
+/*
+ The BlockAttrs spec type is similar to an Attr spec block of a map type,
+ but it produces a map from the attributes of a block rather than from an
+ attribute's expression.
+
+ ```hcl
+ BlockAttrs {
+   name     = "variables"
+   type     = string
+   required = false
+ }
+ ```
+
+ This allows a map with user-defined keys to be produced within block syntax,
+ but due to the constraints of that syntax it also means that the user will
+ be unable to dynamically-generate either individual key names using key
+ expressions or the entire map value using a `for` expression.
+
+ `BlockAttrs` spec blocks accept the following arguments:
+
+ * `name` (required) - The block type name to expect within the HCL
+   input file. This may be omitted when a default name selector is created
+   by a parent `object` spec, if the input block type name should match the
+   output JSON object property name.
+
+ * `type` (required) - The value type to require for each of the
+   attributes within a matched block. The resulting value will be a JSON
+   object whose property values are of this type.
+
+ * `required` (optional) - If `true`, an error will be produced if a block
+   of the given type is not present. If `false` -- the default -- an absent
+   block will be indicated by producing `null`.
+*/
+message BlockAttrs {
+ string name = 1;
+ string type = 2;
+ bool required = 3;
+}
+
 /* BlockList spec type is similar to `Block`, but it accepts zero or
 more blocks of a specified type rather than requiring zero or one. The
 result is a JSON array with one entry per block of the given type.

plugins/shared/hclspec/spec.go

@@ -36,6 +36,15 @@ func BlockSpec(block *Block) *Spec {
 	}
 }
 
+// BlockAttrsSpec wraps the block attrs and returns a spec.
+func BlockAttrsSpec(blockAttrs *BlockAttrs) *Spec {
+	return &Spec{
+		Block: &Spec_BlockAttrs{
+			BlockAttrs: blockAttrs,
+		},
+	}
+}
+
 // BlockListSpec wraps the block list and returns a spec.
 func BlockListSpec(blockList *BlockList) *Spec {
 	return &Spec{
@@ -106,6 +115,15 @@ func NewBlock(name string, required bool, nested *Spec) *Spec {
 	})
 }
 
+// NewBlockAttrs returns a new block attrs spec
+func NewBlockAttrs(name, elementType string, required bool) *Spec {
+	return BlockAttrsSpec(&BlockAttrs{
+		Name:     name,
+		Required: required,
+		Type:     elementType,
+	})
+}
+
 // NewBlockList returns a new block list spec that has no limits.
 func NewBlockList(name string, nested *Spec) *Spec {
 	return NewBlockListLimited(name, 0, 0, nested)