Move to using ectx to preload build names (#11432)

* Add basic post-processor test

Closes #11411

hcl2template/testdata/build/post-processor_build_name_interpolation.pkr.hcl

@@ -0,0 +1,13 @@
+build {
+    name = "test-build"
+    sources = [ "source.virtualbox-iso.ubuntu-1204" ]
+
+    post-processor "manifest" {
+        name         = build.name
+        slice_string = ["${packer.version}", "${build.name}"]
+    }
+
+}
+
+source "virtualbox-iso" "ubuntu-1204" {
+}

hcl2template/testdata/build/provisioner_build_name_interpolation.pkr.hcl

@@ -0,0 +1,17 @@
+
+// starts resources to provision them.
+build {
+    name = "build-name-test"
+    sources = [
+        "source.virtualbox-iso.ubuntu-1204",
+    ]
+
+    provisioner "shell" {
+        name = build.name
+        slice_string = ["${build.name}"]
+    }
+}
+
+source "virtualbox-iso" "ubuntu-1204" {
+}
+

hcl2template/types.build.go

@@ -8,6 +8,7 @@ import (
 	"github.com/hashicorp/hcl/v2/hclsyntax"
 	packerregistry "github.com/hashicorp/packer/internal/registry"
 	"github.com/hashicorp/packer/internal/registry/env"
+	"github.com/zclconf/go-cty/cty"
 )
 
 const (
@@ -105,6 +106,12 @@ func (p *Parser) decodeBuildConfig(block *hcl.Block, cfg *PackerConfig) (*BuildB
 	build.Name = b.Name
 	build.Description = b.Description
 
+	// Expose build.name during parsing of pps and provisioners
+	ectx := cfg.EvalContext(BuildContext, nil)
+	ectx.Variables[buildAccessor] = cty.ObjectVal(map[string]cty.Value{
+		"name": cty.StringVal(b.Name),
+	})
+
 	for _, buildFrom := range b.FromSources {
 		ref := sourceRefFromString(buildFrom)
 
@@ -158,7 +165,7 @@ func (p *Parser) decodeBuildConfig(block *hcl.Block, cfg *PackerConfig) (*BuildB
 			}
 			build.Sources = append(build.Sources, ref)
 		case buildProvisionerLabel:
-			p, moreDiags := p.decodeProvisioner(block, cfg)
+			p, moreDiags := p.decodeProvisioner(block, ectx)
 			diags = append(diags, moreDiags...)
 			if moreDiags.HasErrors() {
 				continue
@@ -173,14 +180,14 @@ func (p *Parser) decodeBuildConfig(block *hcl.Block, cfg *PackerConfig) (*BuildB
 				})
 				continue
 			}
-			p, moreDiags := p.decodeProvisioner(block, cfg)
+			p, moreDiags := p.decodeProvisioner(block, ectx)
 			diags = append(diags, moreDiags...)
 			if moreDiags.HasErrors() {
 				continue
 			}
 			build.ErrorCleanupProvisionerBlock = p
 		case buildPostProcessorLabel:
-			pp, moreDiags := p.decodePostProcessor(block, cfg)
+			pp, moreDiags := p.decodePostProcessor(block, ectx)
 			diags = append(diags, moreDiags...)
 			if moreDiags.HasErrors() {
 				continue
@@ -197,7 +204,7 @@ func (p *Parser) decodeBuildConfig(block *hcl.Block, cfg *PackerConfig) (*BuildB
 			errored := false
 			postProcessors := []*PostProcessorBlock{}
 			for _, block := range content.Blocks {
-				pp, moreDiags := p.decodePostProcessor(block, cfg)
+				pp, moreDiags := p.decodePostProcessor(block, ectx)
 				diags = append(diags, moreDiags...)
 				if moreDiags.HasErrors() {
 					errored = true

hcl2template/types.build.post-processor.go

@@ -23,7 +23,7 @@ func (p *PostProcessorBlock) String() string {
 	return fmt.Sprintf(buildPostProcessorLabel+"-block %q %q", p.PType, p.PName)
 }
 
-func (p *Parser) decodePostProcessor(block *hcl.Block, cfg *PackerConfig) (*PostProcessorBlock, hcl.Diagnostics) {
+func (p *Parser) decodePostProcessor(block *hcl.Block, ectx *hcl.EvalContext) (*PostProcessorBlock, hcl.Diagnostics) {
 	var b struct {
 		Name              string   `hcl:"name,optional"`
 		Only              []string `hcl:"only,optional"`
@@ -31,7 +31,8 @@ func (p *Parser) decodePostProcessor(block *hcl.Block, cfg *PackerConfig) (*Post
 		KeepInputArtifact *bool    `hcl:"keep_input_artifact,optional"`
 		Rest              hcl.Body `hcl:",remain"`
 	}
-	diags := gohcl.DecodeBody(block.Body, cfg.EvalContext(BuildContext, nil), &b)
+
+	diags := gohcl.DecodeBody(block.Body, ectx, &b)
 	if diags.HasErrors() {
 		return nil, diags
 	}

hcl2template/types.build.provisioners.go

@@ -74,7 +74,7 @@ func (p *ProvisionerBlock) String() string {
 	return fmt.Sprintf(buildProvisionerLabel+"-block %q %q", p.PType, p.PName)
 }
 
-func (p *Parser) decodeProvisioner(block *hcl.Block, cfg *PackerConfig) (*ProvisionerBlock, hcl.Diagnostics) {
+func (p *Parser) decodeProvisioner(block *hcl.Block, ectx *hcl.EvalContext) (*ProvisionerBlock, hcl.Diagnostics) {
 	var b struct {
 		Name        string    `hcl:"name,optional"`
 		PauseBefore string    `hcl:"pause_before,optional"`
@@ -85,7 +85,7 @@ func (p *Parser) decodeProvisioner(block *hcl.Block, cfg *PackerConfig) (*Provis
 		Override    cty.Value `hcl:"override,optional"`
 		Rest        hcl.Body  `hcl:",remain"`
 	}
-	diags := gohcl.DecodeBody(block.Body, cfg.EvalContext(BuildContext, nil), &b)
+	diags := gohcl.DecodeBody(block.Body, ectx, &b)
 	if diags.HasErrors() {
 		return nil, diags
 	}

hcl2template/types.build_test.go

@@ -534,6 +534,120 @@ func TestParse_build(t *testing.T) {
 			[]packersdk.Build{},
 			false,
 		},
+		{"use build.name in post-processor block",
+			defaultParser,
+			parseTestArgs{"testdata/build/post-processor_build_name_interpolation.pkr.hcl", nil, nil},
+			&PackerConfig{
+				CorePackerVersionString: lockedVersion,
+				Basedir:                 filepath.Join("testdata", "build"),
+				Sources: map[SourceRef]SourceBlock{
+					refVBIsoUbuntu1204: {Type: "virtualbox-iso", Name: "ubuntu-1204"},
+				},
+				Builds: Builds{
+					&BuildBlock{
+						Name: "test-build",
+						Sources: []SourceUseBlock{
+							{
+								SourceRef: refVBIsoUbuntu1204,
+							},
+						},
+						PostProcessorsLists: [][]*PostProcessorBlock{
+							{
+								{
+									PName: "test-build",
+									PType: "manifest",
+								},
+							},
+						},
+					},
+				},
+			},
+			false, false,
+			[]packersdk.Build{
+				&packer.CoreBuild{
+					BuildName:    "test-build",
+					Type:         "virtualbox-iso.ubuntu-1204",
+					Prepared:     true,
+					Builder:      emptyMockBuilder,
+					Provisioners: []packer.CoreBuildProvisioner{},
+					PostProcessors: [][]packer.CoreBuildPostProcessor{
+						{
+							{
+								PName: "test-build",
+								PType: "manifest",
+								PostProcessor: &HCL2PostProcessor{
+									PostProcessor: &MockPostProcessor{
+										Config: MockConfig{
+											NestedMockConfig: NestedMockConfig{
+												Tags:        []MockTag{},
+												SliceString: []string{lockedVersion, "test-build"},
+											},
+											NestedSlice: []NestedMockConfig{},
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+			false,
+		},
+		{"use build.name in provisioner block",
+			defaultParser,
+			parseTestArgs{"testdata/build/provisioner_build_name_interpolation.pkr.hcl", nil, nil},
+			&PackerConfig{
+				CorePackerVersionString: lockedVersion,
+				Basedir:                 filepath.Join("testdata", "build"),
+				Sources: map[SourceRef]SourceBlock{
+					refVBIsoUbuntu1204: {Type: "virtualbox-iso", Name: "ubuntu-1204"},
+				},
+				Builds: Builds{
+					&BuildBlock{
+						Name: "build-name-test",
+						Sources: []SourceUseBlock{
+							{
+								SourceRef: refVBIsoUbuntu1204,
+							},
+						},
+						ProvisionerBlocks: []*ProvisionerBlock{
+							{
+								PName: "build-name-test",
+								PType: "shell",
+							},
+						},
+					},
+				},
+			},
+			false, false,
+			[]packersdk.Build{
+				&packer.CoreBuild{
+					BuildName: "build-name-test",
+					Type:      "virtualbox-iso.ubuntu-1204",
+					Prepared:  true,
+					Builder:   emptyMockBuilder,
+					Provisioners: []packer.CoreBuildProvisioner{
+						{
+							PName: "build-name-test",
+							PType: "shell",
+							Provisioner: &HCL2Provisioner{
+								Provisioner: &MockProvisioner{
+									Config: MockConfig{
+										NestedMockConfig: NestedMockConfig{
+											Tags:        []MockTag{},
+											SliceString: []string{"build-name-test"},
+										},
+										NestedSlice: []NestedMockConfig{},
+									},
+								},
+							},
+						},
+					},
+					PostProcessors: [][]packer.CoreBuildPostProcessor{},
+				},
+			},
+			false,
+		},
 	}
 	testParse(t, tests)
 }