enabling hcp multibuilds

hcl2template/testdata/hcp_par/multibuild-hcp-registry-in-build-block.pkr.hcl

@@ -0,0 +1,15 @@
+source "null" "test" {
+  communicator = "none"
+}
+
+build {
+  name = "bucket-slug-1"
+  hcp_packer_registry {
+    bucket_name = "ok-Bucket-name-1"
+  }
+  sources = ["null.test"]
+}
+build {
+  name = "bucket-slug-2"
+  sources = ["null.test"]
+}

hcl2template/testdata/hcp_par/multibuild-ok.pkr.hcl

@@ -0,0 +1,16 @@
+source "null" "test" {
+  communicator = "none"
+}
+
+hcp_packer_registry {
+  bucket_name = "ok-Bucket-name-1"
+}
+
+build {
+  name = "bucket-slug-1"
+  sources = ["null.test"]
+}
+build {
+  name = "bucket-slug-2"
+  sources = ["null.test"]
+}

hcl2template/types.build.hcp_packer_registry_test.go

@@ -123,9 +123,8 @@ func Test_ParseHCPPackerRegistryBlock(t *testing.T) {
 			},
 			false,
 			&getHCPPackerRegistry{
-				wantBlock:        &HCPPackerRegistryBlock{Slug: "ok-Bucket-name-1"},
 				wantDiag:         true,
-				wantDiagHasError: false,
+				wantDiagHasError: true,
 			},
 		},
 		{"bucket name OK multiple block second build block",
@@ -186,9 +185,8 @@ func Test_ParseHCPPackerRegistryBlock(t *testing.T) {
 			},
 			false,
 			&getHCPPackerRegistry{
-				wantBlock:        &HCPPackerRegistryBlock{Slug: "ok-Bucket-name-1"},
 				wantDiag:         true,
-				wantDiagHasError: false,
+				wantDiagHasError: true,
 			},
 		},
 		{"bucket name OK multiple block multiple declaration",
@@ -250,7 +248,6 @@ func Test_ParseHCPPackerRegistryBlock(t *testing.T) {
 			},
 			false,
 			&getHCPPackerRegistry{
-				wantBlock:        &HCPPackerRegistryBlock{Slug: "ok-Bucket-name-1"},
 				wantDiag:         true,
 				wantDiagHasError: true,
 			},
@@ -661,6 +658,132 @@ func Test_ParseHCPPackerRegistryBlock(t *testing.T) {
 				wantDiagHasError: true,
 			},
 		},
-	}
+
+		{"multiple build block with Hcp Packer Registry in a build block",
+			defaultParser,
+			parseTestArgs{"testdata/hcp_par/multibuild-hcp-registry-in-build-block.pkr.hcl", nil, nil},
+			&PackerConfig{
+				CorePackerVersionString: lockedVersion,
+				Basedir:                 filepath.Join("testdata", "hcp_par"),
+				Sources: map[SourceRef]SourceBlock{
+					refNull: {
+						Type: "null",
+						Name: "test",
+						block: &hcl.Block{
+							Type: "source",
+						},
+					},
+				},
+				Builds: Builds{
+					{
+						Name:              "bucket-slug-1",
+						HCPPackerRegistry: &HCPPackerRegistryBlock{Slug: "ok-Bucket-name-1"},
+						Sources: []SourceUseBlock{
+							{
+								SourceRef: refNull,
+							},
+						},
+					},
+					{
+						Name: "bucket-slug-2",
+						Sources: []SourceUseBlock{
+							{
+								SourceRef: refNull,
+							},
+						},
+					},
+				},
+			},
+			false, false,
+			[]*packer.CoreBuild{
+				&packer.CoreBuild{
+					BuildName:      "bucket-slug-1",
+					Type:           "null.test",
+					Builder:        &null.Builder{},
+					Provisioners:   []packer.CoreBuildProvisioner{},
+					PostProcessors: [][]packer.CoreBuildPostProcessor{},
+					Prepared:       true,
+					BuilderType:    "null",
+				},
+				&packer.CoreBuild{
+					BuildName:      "bucket-slug-2",
+					Type:           "null.test",
+					Builder:        &null.Builder{},
+					Provisioners:   []packer.CoreBuildProvisioner{},
+					PostProcessors: [][]packer.CoreBuildPostProcessor{},
+					Prepared:       true,
+					BuilderType:    "null",
+				},
+			},
+			false,
+			&getHCPPackerRegistry{
+				// wantBlock:        &HCPPackerRegistryBlock{Slug: "ok-Bucket-name-1"},
+				wantDiag:         true,
+				wantDiagHasError: true,
+			},
+		},
+		{"multiple build block",
+			defaultParser,
+			parseTestArgs{"testdata/hcp_par/multibuild-ok.pkr.hcl", nil, nil},
+			&PackerConfig{
+				CorePackerVersionString: lockedVersion,
+				Basedir:                 filepath.Join("testdata", "hcp_par"),
+				HCPPackerRegistry:       &HCPPackerRegistryBlock{Slug: "ok-Bucket-name-1"},
+				Sources: map[SourceRef]SourceBlock{
+					refNull: {
+						Type: "null",
+						Name: "test",
+						block: &hcl.Block{
+							Type: "source",
+						},
+					},
+				},
+				Builds: Builds{
+					{
+						Name: "bucket-slug-1",
+						Sources: []SourceUseBlock{
+							{
+								SourceRef: refNull,
+							},
+						},
+					},
+					{
+						Name: "bucket-slug-2",
+						Sources: []SourceUseBlock{
+							{
+								SourceRef: refNull,
+							},
+						},
+					},
+				},
+			},
+			false, false,
+			[]*packer.CoreBuild{
+				&packer.CoreBuild{
+					BuildName:      "bucket-slug-1",
+					Type:           "null.test",
+					Builder:        &null.Builder{},
+					Provisioners:   []packer.CoreBuildProvisioner{},
+					PostProcessors: [][]packer.CoreBuildPostProcessor{},
+					Prepared:       true,
+					BuilderType:    "null",
+				},
+				&packer.CoreBuild{
+					BuildName:      "bucket-slug-2",
+					Type:           "null.test",
+					Builder:        &null.Builder{},
+					Provisioners:   []packer.CoreBuildProvisioner{},
+					PostProcessors: [][]packer.CoreBuildPostProcessor{},
+					Prepared:       true,
+					BuilderType:    "null",
+				},
+			},
+			false,
+			&getHCPPackerRegistry{
+				wantBlock:        &HCPPackerRegistryBlock{Slug: "ok-Bucket-name-1"},
+				wantDiag:         false,
+				wantDiagHasError: false,
+			},
+		}}
 	testParse(t, tests)
 }

hcl2template/types.packer_config.go

@@ -650,25 +650,10 @@ func (cfg *PackerConfig) GetHCPPackerRegistryBlock() (*HCPPackerRegistryBlock, h
 	var block *HCPPackerRegistryBlock
 	var diags hcl.Diagnostics
 
-	multipleRegistryDiag := func(block *HCPPackerRegistryBlock) *hcl.Diagnostic {
-		return &hcl.Diagnostic{
-			Summary:  "Multiple HCP Packer registry block declaration",
-			Subject:  block.HCL2Ref.DefRange.Ptr(),
-			Severity: hcl.DiagError,
-			Detail: "Multiple " + buildHCPPackerRegistryLabel + " blocks have been found, only one can be defined " +
-				"in HCL2 templates. Starting with Packer 1.12.1, it is recommended to move it to the " +
-				"top-level configuration instead of within a build block.",
-		}
-	}
-	// We start by looking in the build blocks
-	for _, build := range cfg.Builds {
-		if build.HCPPackerRegistry != nil {
-			if block != nil {
-				// error multiple build block
-				diags = diags.Append(multipleRegistryDiag(build.HCPPackerRegistry))
-				continue
-			}
-			block = build.HCPPackerRegistry
+	// build block leveled hcp registry is only tolerated when there is only one build block
+	if len(cfg.Builds) == 1 {
+		if cfg.Builds[0].HCPPackerRegistry != nil {
+			block = cfg.Builds[0].HCPPackerRegistry
 			diags = diags.Append(&hcl.Diagnostic{
 				Summary:  "Build block level " + buildHCPPackerRegistryLabel + " are deprecated",
 				Subject:  &block.DefRange,
@@ -677,10 +662,30 @@ func (cfg *PackerConfig) GetHCPPackerRegistryBlock() (*HCPPackerRegistryBlock, h
 					"top-level configuration instead of within a build block.",
 			})
 		}
+	} else {
+		// else we make sure no HCPPackerRegistry has been declared
+		for _, build := range cfg.Builds {
+			if build.HCPPackerRegistry != nil {
+				diags = diags.Append(&hcl.Diagnostic{
+					Summary:  "Build block level " + buildHCPPackerRegistryLabel + " are illegal in multiple builds",
+					Subject:  &build.HCPPackerRegistry.DefRange,
+					Severity: hcl.DiagError,
+					Detail: "When using multiple builds block with HCP Packer, it is mandatory to move " +
+						"hcp_packer_registry to the top-level configuration instead of within a build block",
+				})
+			}
+		}
 	}
-
 	if block != nil && cfg.HCPPackerRegistry != nil {
-		diags = diags.Append(multipleRegistryDiag(block))
+		diags = diags.Append(
+			&hcl.Diagnostic{
+				Summary:  "Multiple HCP Packer registry block declaration",
+				Subject:  block.HCL2Ref.DefRange.Ptr(),
+				Severity: hcl.DiagError,
+				Detail: "Multiple " + buildHCPPackerRegistryLabel + " blocks have been found, only one can be defined " +
+					"in HCL2 templates. Starting with Packer 1.12.1, it is recommended to move it to the " +
+					"top-level configuration instead of within a build block.",
+			})
 	}
 
 	if cfg.HCPPackerRegistry != nil {

internal/hcp/registry/hcl.go

@@ -93,18 +93,6 @@ func (h *HCLRegistry) VersionStatusSummary() {
 
 func NewHCLRegistry(config *hcl2template.PackerConfig, ui sdkpacker.Ui) (*HCLRegistry, hcl.Diagnostics) {
 	var diags hcl.Diagnostics
-	if len(config.Builds) > 1 {
-		diags = append(diags, &hcl.Diagnostic{
-			Severity: hcl.DiagError,
-			Summary:  "Multiple " + buildLabel + " blocks",
-			Detail: fmt.Sprintf("For HCP Packer Registry enabled builds, only one " + buildLabel +
-				" block can be defined. Please remove any additional " + buildLabel +
-				" block(s). If this " + buildLabel + " is not meant for the HCP Packer registry please " +
-				"clear any HCP_PACKER_* environment variables."),
-		})
-
-		return nil, diags
-	}
 
 	registryConfig, rcDiags := config.GetHCPPackerRegistryBlock()
 	diags = diags.Extend(rcDiags)
@@ -176,9 +164,9 @@ func (h *HCLRegistry) registerAllComponents() hcl.Diagnostics {
 
 	conflictSources := map[string]struct{}{}
 
-	// we currently support only one build block but it will change in the near future
 	for _, build := range h.configuration.Builds {
 		for _, source := range build.Sources {
+
 			// If we encounter the same source twice, we'll defer
 			// its addition to later, using both the build name
 			// and the source type as the name used for HCP Packer.
@@ -205,23 +193,46 @@ func (h *HCLRegistry) registerAllComponents() hcl.Diagnostics {
 	// If that happens, we then use a combination of both the build name, and
 	// the source type.
 	for _, build := range h.configuration.Builds {
+		// this set is used to catch duplicate sources in the same block
+		sources := map[string]struct{}{}
 		for _, source := range build.Sources {
+			if _, ok := sources[source.String()]; !ok {
+				sources[source.String()] = struct{}{}
+			} else {
+				diags = append(diags, &hcl.Diagnostic{
+					Severity: hcl.DiagError,
+					Summary:  "Source conflicts",
+					Subject:  &build.HCL2Ref.DefRange,
+					Detail: fmt.Sprintf("Two or more sources are identical inside the same "+
+						"build block, there should be only one instance of %s", source.String()),
+				})
+				continue
+			}
 			if _, ok := conflictSources[source.String()]; !ok {
 				continue
 			}
 
-			buildName := source.String()
-			if build.Name != "" {
-				buildName = fmt.Sprintf("%s.%s", build.Name, buildName)
+			if build.Name == "" {
+				diags = append(diags, &hcl.Diagnostic{
+					Severity: hcl.DiagError,
+					Summary:  "Missing mandatory build name",
+					Subject:  &build.HCL2Ref.DefRange,
+					Detail: "A build name is required when using the same source in two or" +
+						" more different builds",
+				})
+				continue
 			}
 
+			buildName := fmt.Sprintf("%s.%s", build.Name, source.String())
+
 			if _, ok := h.buildNames[buildName]; ok {
 				diags = append(diags, &hcl.Diagnostic{
 					Severity: hcl.DiagError,
 					Summary:  "Build name conflicts",
 					Subject:  &build.HCL2Ref.DefRange,
-					Detail: fmt.Sprintf("Two sources are used in the same build block, causing "+
-						"a conflict, there must only be one instance of %s", source.String()),
+					Detail: fmt.Sprintf("Two sources are used in the same build block or "+
+						"two builds have the same name, causing a conflict, there must only "+
+						"be one instance of %s", source.String()),
 				})
 			}
 			h.buildNames[buildName] = struct{}{}

internal/hcp/registry/hcl_test.go

@@ -172,7 +172,7 @@ func TestNewRegisterProperBuildName(t *testing.T) {
 		},
 		"multiple build block with same source create conflict": {
 			expectErr:            true,
-			diagsSummaryContains: "conflict",
+			diagsSummaryContains: "mandatory build name",
 			builds: hcl2template.Builds{
 				&hcl2template.BuildBlock{
 					Sources: []hcl2template.SourceUseBlock{
@@ -237,8 +237,7 @@ func TestNewRegisterProperBuildName(t *testing.T) {
 			},
 		},
 		"multiple build block with same source but with only one declared build name": {
-			expectErr:      false,
-			expectedBuilds: []string{"docker.ubuntu", "build.docker.ubuntu"},
+			expectErr: true,
 			builds: hcl2template.Builds{
 				&hcl2template.BuildBlock{
 					Name: "build",