configs: added map to configs.Module for provider local name lookup (#24039)

* configs: added map of ProviderLocalNames to configs.Module

We will need to lookup any user-supplied local names for a given FQN.
This PR adds a map of ProviderLocalNames to the Module, along with
adding tests for this and for decodeRequiredProvidersBlock.

This also introduces the appearance of support for a required_provider
"source" attribute, but ignores any user-supplied source and instead
continues to assume that addrs.NewLegacyProvider is the way to go.

configs/module.go

@@ -31,6 +31,7 @@ type Module struct {
 	Backend              *Backend
 	ProviderConfigs      map[string]*Provider
 	ProviderRequirements map[string]ProviderRequirements
+	ProviderLocalNames   map[addrs.Provider]string
 
 	Variables map[string]*Variable
 	Locals    map[string]*Local
@@ -85,6 +86,7 @@ func NewModule(primaryFiles, overrideFiles []*File) (*Module, hcl.Diagnostics) {
 	mod := &Module{
 		ProviderConfigs:      map[string]*Provider{},
 		ProviderRequirements: map[string]ProviderRequirements{},
+		ProviderLocalNames:   map[addrs.Provider]string{},
 		Variables:            map[string]*Variable{},
 		Locals:               map[string]*Local{},
 		Outputs:              map[string]*Output{},
@@ -105,6 +107,9 @@ func NewModule(primaryFiles, overrideFiles []*File) (*Module, hcl.Diagnostics) {
 
 	diags = append(diags, checkModuleExperiments(mod)...)
 
+	// Generate the FQN -> LocalProviderName map
+	mod.gatherProviderLocalNames()
+
 	return mod, diags
 }
 
@@ -170,11 +175,14 @@ func (m *Module) appendFile(file *File) hcl.Diagnostics {
 	}
 
 	for _, reqd := range file.RequiredProviders {
-		// TODO: once the remaining provider source functionality is
+		// As an interim *testing* step, we will accept a source argument
-		// implemented, get addrs.Provider from source if set, or
+		// but assume that the source is a legacy provider. This allows us to
-		// addrs.NewDefaultProvider(name) if not
+		// exercise the provider local names -> fqn logic without changing
+		// terraform's behavior.
 		if reqd.Source != "" {
-			panic("source is not yet supported")
+			// Fixme: once the rest of the provider source logic is implemented,
+			// update this to get the addrs.Provider by using
+			// addrs.ParseProviderSourceString()
 		}
 		fqn := addrs.NewLegacyProvider(reqd.Name)
 		if existing, exists := m.ProviderRequirements[reqd.Name]; exists {
@@ -425,3 +433,27 @@ func (m *Module) mergeFile(file *File) hcl.Diagnostics {
 
 	return diags
 }
+
+// gatherProviderLocalNames is a helper function that populatesA a map of
+// provider FQNs -> provider local names. This information is useful for
+// user-facing output, which should include both the FQN and LocalName. It must
+// only be populated after the module has been parsed.
+func (m *Module) gatherProviderLocalNames() {
+	providers := make(map[addrs.Provider]string)
+	for k, v := range m.ProviderRequirements {
+		providers[v.Type] = k
+	}
+	m.ProviderLocalNames = providers
+}
+
+// LocalNameForProvider returns the module-specific user-supplied local name for
+// a given provider FQN, or the default local name if none was supplied.
+func (m *Module) LocalNameForProvider(p addrs.Provider) string {
+	if existing, exists := m.ProviderLocalNames[p]; exists {
+		return existing
+	} else {
+		// If there isn't a map entry, fall back to the default:
+		// Type = LocalName
+		return p.Type
+	}
+}

configs/module_test.go

@@ -0,0 +1,34 @@
+package configs
+
+import (
+	"testing"
+
+	"github.com/hashicorp/terraform/addrs"
+)
+
+// TestNewModule_provider_fqns exercises module.gatherProviderLocalNames()
+func TestNewModule_provider_local_name(t *testing.T) {
+	mod, diags := testModuleFromDir("testdata/providers-explicit-fqn")
+	if diags.HasErrors() {
+		t.Fatal(diags.Error())
+	}
+
+	// FIXME: while the provider source is set to "foo/test", terraform
+	// currently assumes everything is a legacy provider and the localname and
+	// type match. This test will be updated when provider source is fully
+	// implemented.
+	p := addrs.NewLegacyProvider("foo_test")
+	if name, exists := mod.ProviderLocalNames[p]; !exists {
+		t.Fatal("provider FQN foo/test not found")
+	} else {
+		if name != "foo_test" {
+			t.Fatalf("provider localname mismatch: got %s, want foo_test", name)
+		}
+	}
+
+	// ensure the reverse lookup (fqn to local name) works as well
+	localName := mod.LocalNameForProvider(p)
+	if localName != "foo_test" {
+		t.Fatal("provider local name not found")
+	}
+}

configs/provider_requirements.go

@@ -9,8 +9,6 @@ import (
 // RequiredProvider represents a declaration of a dependency on a particular
 // provider version without actually configuring that provider. This is used in
 // child modules that expect a provider to be passed in from their parent.
-//
-// TODO: "Source" is a placeholder for an attribute that is not yet supported.
 type RequiredProvider struct {
 	Name        string
 	Source      string // TODO
@@ -43,6 +41,7 @@ func decodeRequiredProvidersBlock(block *hcl.Block) ([]*RequiredProvider, hcl.Di
 				Requirement: vc,
 			})
 		case expr.Type().IsObjectType():
+			ret := &RequiredProvider{Name: name}
 			if expr.Type().HasAttribute("version") {
 				vc := VersionConstraint{
 					DeclRange: attr.Range,
@@ -58,14 +57,15 @@ func decodeRequiredProvidersBlock(block *hcl.Block) ([]*RequiredProvider, hcl.Di
 						Detail:   "This string does not use correct version constraint syntax.",
 						Subject:  attr.Expr.Range().Ptr(),
 					})
-					reqs = append(reqs, &RequiredProvider{Name: name})
+				} else {
-					return reqs, diags
+					vc.Required = constraints
+					ret.Requirement = vc
 				}
-				vc.Required = constraints
-				reqs = append(reqs, &RequiredProvider{Name: name, Requirement: vc})
 			}
-			// No version
+			if expr.Type().HasAttribute("source") {
-			reqs = append(reqs, &RequiredProvider{Name: name})
+				ret.Source = expr.GetAttr("source").AsString()
+			}
+			reqs = append(reqs, ret)
 		default:
 			// should not happen
 			diags = append(diags, &hcl.Diagnostic{

configs/provider_requirements_test.go

@@ -0,0 +1,185 @@
+package configs
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-cmp/cmp/cmpopts"
+	version "github.com/hashicorp/go-version"
+	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/hcl/v2/hcltest"
+	"github.com/zclconf/go-cty/cty"
+)
+
+var (
+	ignoreUnexported = cmpopts.IgnoreUnexported(version.Constraint{})
+	comparer         = cmp.Comparer(func(x, y RequiredProvider) bool {
+		if x.Name != y.Name {
+			return false
+		}
+		if x.Source != y.Source {
+			return false
+		}
+		if x.Requirement.Required.String() != y.Requirement.Required.String() {
+			return false
+		}
+		return true
+	})
+)
+
+func TestDecodeRequiredProvidersBlock_legacy(t *testing.T) {
+	block := &hcl.Block{
+		Type: "required_providers",
+		Body: hcltest.MockBody(&hcl.BodyContent{
+			Attributes: hcl.Attributes{
+				"default": {
+					Name: "default",
+					Expr: hcltest.MockExprLiteral(cty.StringVal("1.0.0")),
+				},
+			},
+		}),
+	}
+
+	want := &RequiredProvider{
+		Name:        "default",
+		Requirement: testVC("1.0.0"),
+	}
+
+	got, diags := decodeRequiredProvidersBlock(block)
+	if diags.HasErrors() {
+		t.Fatalf("unexpected error")
+	}
+	if len(got) != 1 {
+		t.Fatalf("wrong number of results, got %d, wanted 1", len(got))
+	}
+	if !cmp.Equal(got[0], want, ignoreUnexported, comparer) {
+		t.Fatalf("wrong result:\n %s", cmp.Diff(got[0], want, ignoreUnexported, comparer))
+	}
+}
+
+func TestDecodeRequiredProvidersBlock_provider_source(t *testing.T) {
+	block := &hcl.Block{
+		Type: "required_providers",
+		Body: hcltest.MockBody(&hcl.BodyContent{
+			Attributes: hcl.Attributes{
+				"my_test": {
+					Name: "my_test",
+					Expr: hcltest.MockExprLiteral(cty.ObjectVal(map[string]cty.Value{
+						"source":  cty.StringVal("mycloud/test"),
+						"version": cty.StringVal("2.0.0"),
+					})),
+				},
+			},
+		}),
+	}
+
+	want := &RequiredProvider{
+		Name:        "my_test",
+		Source:      "mycloud/test",
+		Requirement: testVC("2.0.0"),
+	}
+	got, diags := decodeRequiredProvidersBlock(block)
+	if diags.HasErrors() {
+		t.Fatalf("unexpected error")
+	}
+	if len(got) != 1 {
+		t.Fatalf("wrong number of results, got %d, wanted 1", len(got))
+	}
+	if !cmp.Equal(got[0], want, ignoreUnexported, comparer) {
+		t.Fatalf("wrong result:\n %s", cmp.Diff(got[0], want, ignoreUnexported, comparer))
+	}
+}
+
+func TestDecodeRequiredProvidersBlock_mixed(t *testing.T) {
+	block := &hcl.Block{
+		Type: "required_providers",
+		Body: hcltest.MockBody(&hcl.BodyContent{
+			Attributes: hcl.Attributes{
+				"legacy": {
+					Name: "legacy",
+					Expr: hcltest.MockExprLiteral(cty.StringVal("1.0.0")),
+				},
+				"my_test": {
+					Name: "my_test",
+					Expr: hcltest.MockExprLiteral(cty.ObjectVal(map[string]cty.Value{
+						"source":  cty.StringVal("mycloud/test"),
+						"version": cty.StringVal("2.0.0"),
+					})),
+				},
+			},
+		}),
+	}
+
+	want := []*RequiredProvider{
+		{
+			Name:        "legacy",
+			Requirement: testVC("1.0.0"),
+		},
+		{
+			Name:        "my_test",
+			Source:      "mycloud/test",
+			Requirement: testVC("2.0.0"),
+		},
+	}
+
+	got, diags := decodeRequiredProvidersBlock(block)
+	if diags.HasErrors() {
+		t.Fatalf("unexpected error")
+	}
+	if len(got) != 2 {
+		t.Fatalf("wrong number of results, got %d, wanted 2", len(got))
+	}
+	for i, rp := range want {
+		if !cmp.Equal(got[i], rp, ignoreUnexported, comparer) {
+			t.Fatalf("wrong result:\n %s", cmp.Diff(got[0], rp, ignoreUnexported, comparer))
+		}
+	}
+}
+
+func TestDecodeRequiredProvidersBlock_version_error(t *testing.T) {
+	block := &hcl.Block{
+		Type: "required_providers",
+		Body: hcltest.MockBody(&hcl.BodyContent{
+			Attributes: hcl.Attributes{
+				"my_test": {
+					Name: "my_test",
+					Expr: hcltest.MockExprLiteral(cty.ObjectVal(map[string]cty.Value{
+						"source":  cty.StringVal("mycloud/test"),
+						"version": cty.StringVal("invalid"),
+					})),
+				},
+			},
+		}),
+	}
+
+	want := []*RequiredProvider{
+		{
+			Name:   "my_test",
+			Source: "mycloud/test",
+		},
+	}
+
+	got, diags := decodeRequiredProvidersBlock(block)
+	if !diags.HasErrors() {
+		t.Fatalf("expected error, got success")
+	} else {
+		fmt.Printf(diags[0].Summary)
+	}
+	if len(got) != 1 {
+		t.Fatalf("wrong number of results, got %d, wanted 1", len(got))
+	}
+	for i, rp := range want {
+		if !cmp.Equal(got[i], rp, ignoreUnexported, comparer) {
+			t.Fatalf("wrong result:\n %s", cmp.Diff(got[0], rp, ignoreUnexported, comparer))
+		}
+	}
+}
+
+func testVC(ver string) VersionConstraint {
+	constraint, _ := version.NewConstraint(ver)
+	return VersionConstraint{
+		Required:  constraint,
+		DeclRange: hcl.Range{},
+	}
+}