configs: extend module.ProviderRequirements to include the addrs.Provider instead of just version constraints. (#23843)

Renamed file.ProviderRequirements to file.RequiredProviders to match the
name of the block in the configuration. file.RequiredProviders contains
the contents of the file(s); module.ProviderRequirements contains the
parsed and merged provider requirements.

Extended decodeRequiredProvidersBlock to parse the new provider source
syntax (version only, it will ignore any other attributes).

Added some tests; swapped deep.Equal with cmp.Equal in the
terraform/module_dependencies_test.go because deep was not catching
incorrect constraints.

configs/module.go

@@ -30,7 +30,7 @@ type Module struct {
 
 	Backend              *Backend
 	ProviderConfigs      map[string]*Provider
-	ProviderRequirements map[string][]VersionConstraint
+	ProviderRequirements map[string]ProviderRequirements
 
 	Variables map[string]*Variable
 	Locals    map[string]*Local
@@ -58,9 +58,9 @@ type File struct {
 
 	ActiveExperiments experiments.Set
 
-	Backends             []*Backend
-	ProviderConfigs      []*Provider
-	ProviderRequirements []*ProviderRequirement
+	Backends          []*Backend
+	ProviderConfigs   []*Provider
+	RequiredProviders []*RequiredProvider
 
 	Variables []*Variable
 	Locals    []*Local
@@ -84,7 +84,7 @@ func NewModule(primaryFiles, overrideFiles []*File) (*Module, hcl.Diagnostics) {
 	var diags hcl.Diagnostics
 	mod := &Module{
 		ProviderConfigs:      map[string]*Provider{},
-		ProviderRequirements: map[string][]VersionConstraint{},
+		ProviderRequirements: map[string]ProviderRequirements{},
 		Variables:            map[string]*Variable{},
 		Locals:               map[string]*Local{},
 		Outputs:              map[string]*Output{},
@@ -103,8 +103,7 @@ func NewModule(primaryFiles, overrideFiles []*File) (*Module, hcl.Diagnostics) {
 		diags = append(diags, fileDiags...)
 	}
 
-	moreDiags := checkModuleExperiments(mod)
-	diags = append(diags, moreDiags...)
+	diags = append(diags, checkModuleExperiments(mod)...)
 
 	return mod, diags
 }
@@ -170,8 +169,22 @@ func (m *Module) appendFile(file *File) hcl.Diagnostics {
 		m.ProviderConfigs[key] = pc
 	}
 
-	for _, reqd := range file.ProviderRequirements {
-		m.ProviderRequirements[reqd.Name] = append(m.ProviderRequirements[reqd.Name], reqd.Requirement)
+	for _, reqd := range file.RequiredProviders {
+		// TODO: once the remaining provider source functionality is
+		// implemented, get addrs.Provider from source if set, or
+		// addrs.NewDefaultProvider(name) if not
+		if reqd.Source != "" {
+			panic("source is not yet supported")
+		}
+		fqn := addrs.NewLegacyProvider(reqd.Name)
+		if existing, exists := m.ProviderRequirements[reqd.Name]; exists {
+			if existing.Type != fqn {
+				panic("provider fqn mismatch")
+			}
+			existing.VersionConstraints = append(existing.VersionConstraints, reqd.Requirement)
+		} else {
+			m.ProviderRequirements[reqd.Name] = ProviderRequirements{Type: fqn, VersionConstraints: []VersionConstraint{reqd.Requirement}}
+		}
 	}
 
 	for _, v := range file.Variables {
@@ -314,8 +327,8 @@ func (m *Module) mergeFile(file *File) hcl.Diagnostics {
 		}
 	}
 
-	if len(file.ProviderRequirements) != 0 {
-		mergeProviderVersionConstraints(m.ProviderRequirements, file.ProviderRequirements)
+	if len(file.RequiredProviders) != 0 {
+		mergeProviderVersionConstraints(m.ProviderRequirements, file.RequiredProviders)
 	}
 
 	for _, v := range file.Variables {

configs/module_merge.go

@@ -35,7 +35,7 @@ func (p *Provider) merge(op *Provider) hcl.Diagnostics {
 	return diags
 }
 
-func mergeProviderVersionConstraints(recv map[string][]VersionConstraint, ovrd []*ProviderRequirement) {
+func mergeProviderVersionConstraints(recv map[string]ProviderRequirements, ovrd []*RequiredProvider) {
 	// Any provider name that's mentioned in the override gets nilled out in
 	// our map so that we'll rebuild it below. Any provider not mentioned is
 	// left unchanged.
@@ -43,7 +43,8 @@ func mergeProviderVersionConstraints(recv map[string][]VersionConstraint, ovrd [
 		delete(recv, reqd.Name)
 	}
 	for _, reqd := range ovrd {
-		recv[reqd.Name] = append(recv[reqd.Name], reqd.Requirement)
+		fqn := addrs.NewLegacyProvider(reqd.Name)
+		recv[reqd.Name] = ProviderRequirements{Type: fqn, VersionConstraints: []VersionConstraint{reqd.Requirement}}
 	}
 }
 

configs/module_merge_test.go

@@ -3,8 +3,10 @@ package configs
 import (
 	"testing"
 
+	version "github.com/hashicorp/go-version"
 	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/hcl/v2/gohcl"
+	"github.com/hashicorp/terraform/addrs"
 	"github.com/zclconf/go-cty/cty"
 )
 
@@ -199,3 +201,77 @@ func TestModuleOverrideDynamic(t *testing.T) {
 		}
 	})
 }
+
+func TestMergeProviderVersionConstraints(t *testing.T) {
+	v1, _ := version.NewConstraint("1.0.0")
+	vc1 := VersionConstraint{
+		Required: v1,
+	}
+	v2, _ := version.NewConstraint("2.0.0")
+	vc2 := VersionConstraint{
+		Required: v2,
+	}
+
+	tests := map[string]struct {
+		Input    map[string]ProviderRequirements
+		Override []*RequiredProvider
+		Want     map[string]ProviderRequirements
+	}{
+		"basic merge": {
+			map[string]ProviderRequirements{
+				"random": ProviderRequirements{
+					Type:               addrs.Provider{Type: "random"},
+					VersionConstraints: []VersionConstraint{},
+				},
+			},
+			[]*RequiredProvider{
+				&RequiredProvider{
+					Name:        "null",
+					Requirement: VersionConstraint{},
+				},
+			},
+			map[string]ProviderRequirements{
+				"random": ProviderRequirements{
+					Type:               addrs.Provider{Type: "random"},
+					VersionConstraints: []VersionConstraint{},
+				},
+				"null": ProviderRequirements{
+					Type: addrs.NewLegacyProvider("null"),
+					VersionConstraints: []VersionConstraint{
+						VersionConstraint{
+							Required:  version.Constraints(nil),
+							DeclRange: hcl.Range{},
+						},
+					},
+				},
+			},
+		},
+		"override version constraint": {
+			map[string]ProviderRequirements{
+				"random": ProviderRequirements{
+					Type:               addrs.Provider{Type: "random"},
+					VersionConstraints: []VersionConstraint{vc1},
+				},
+			},
+			[]*RequiredProvider{
+				&RequiredProvider{
+					Name:        "random",
+					Requirement: vc2,
+				},
+			},
+			map[string]ProviderRequirements{
+				"random": ProviderRequirements{
+					Type:               addrs.NewLegacyProvider("random"),
+					VersionConstraints: []VersionConstraint{vc2},
+				},
+			},
+		},
+	}
+
+	for name, test := range tests {
+		t.Run(name, func(t *testing.T) {
+			mergeProviderVersionConstraints(test.Input, test.Override)
+			assertResultDeepEqual(t, test.Input, test.Want)
+		})
+	}
+}

configs/parser_config.go

@@ -75,7 +75,7 @@ func (p *Parser) loadConfigFile(path string, override bool) (*File, hcl.Diagnost
 				case "required_providers":
 					reqs, reqsDiags := decodeRequiredProvidersBlock(innerBlock)
 					diags = append(diags, reqsDiags...)
-					file.ProviderRequirements = append(file.ProviderRequirements, reqs...)
+					file.RequiredProviders = append(file.RequiredProviders, reqs...)
 
 				default:
 					// Should never happen because the above cases should be exhaustive

configs/provider_requirements.go

@@ -3,22 +3,31 @@ package configs
 import (
 	version "github.com/hashicorp/go-version"
 	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/terraform/addrs"
 )
 
-// ProviderRequirement represents a declaration of a dependency on a particular
+// 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 ProviderRequirement struct {
+type RequiredProvider struct {
 	Name        string
 	Source      string // TODO
 	Requirement VersionConstraint
 }
 
-func decodeRequiredProvidersBlock(block *hcl.Block) ([]*ProviderRequirement, hcl.Diagnostics) {
+// ProviderRequirements represents merged provider version constraints.
+// VersionConstraints come from terraform.require_providers blocks and provider
+// blocks.
+type ProviderRequirements struct {
+	Type               addrs.Provider
+	VersionConstraints []VersionConstraint
+}
+
+func decodeRequiredProvidersBlock(block *hcl.Block) ([]*RequiredProvider, hcl.Diagnostics) {
 	attrs, diags := block.Body.JustAttributes()
-	var reqs []*ProviderRequirement
+	var reqs []*RequiredProvider
 	for name, attr := range attrs {
 		expr, err := attr.Expr.Value(nil)
 		if err != nil {
@@ -29,7 +38,7 @@ func decodeRequiredProvidersBlock(block *hcl.Block) ([]*ProviderRequirement, hcl
 		case expr.Type().IsPrimitiveType():
 			vc, reqDiags := decodeVersionConstraint(attr)
 			diags = append(diags, reqDiags...)
-			reqs = append(reqs, &ProviderRequirement{
+			reqs = append(reqs, &RequiredProvider{
 				Name:        name,
 				Requirement: vc,
 			})
@@ -49,14 +58,14 @@ func decodeRequiredProvidersBlock(block *hcl.Block) ([]*ProviderRequirement, hcl
 						Detail:   "This string does not use correct version constraint syntax.",
 						Subject:  attr.Expr.Range().Ptr(),
 					})
-					reqs = append(reqs, &ProviderRequirement{Name: name})
+					reqs = append(reqs, &RequiredProvider{Name: name})
 					return reqs, diags
 				}
 				vc.Required = constraints
-				reqs = append(reqs, &ProviderRequirement{Name: name, Requirement: vc})
+				reqs = append(reqs, &RequiredProvider{Name: name, Requirement: vc})
 			}
 			// No version
-			reqs = append(reqs, &ProviderRequirement{Name: name})
+			reqs = append(reqs, &RequiredProvider{Name: name})
 		default:
 			// should not happen
 			diags = append(diags, &hcl.Diagnostic{
@@ -65,7 +74,7 @@ func decodeRequiredProvidersBlock(block *hcl.Block) ([]*ProviderRequirement, hcl
 				Detail:   "provider_requirements entries must be strings or objects.",
 				Subject:  attr.Expr.Range().Ptr(),
 			})
-			reqs = append(reqs, &ProviderRequirement{Name: name})
+			reqs = append(reqs, &RequiredProvider{Name: name})
 			return reqs, diags
 		}
 	}

terraform/module_dependencies.go

@@ -58,9 +58,8 @@ func configTreeConfigDependencies(root *configs.Config, inheritProviders map[str
 		// The main way to declare a provider dependency is explicitly inside
 		// the "terraform" block, which allows declaring a requirement without
 		// also creating a configuration.
-		for fullName, constraints := range module.ProviderRequirements {
+		for fullName, req := range module.ProviderRequirements {
 			inst := moduledeps.ProviderInstance(fullName)
-
 			// The handling here is a bit fiddly because the moduledeps package
 			// was designed around the legacy (pre-0.12) configuration model
 			// and hasn't yet been revised to handle the new model. As a result,
@@ -69,7 +68,7 @@ func configTreeConfigDependencies(root *configs.Config, inheritProviders map[str
 			// can also retain the source location of each constraint, for
 			// more informative output from the "terraform providers" command.
 			var rawConstraints version.Constraints
-			for _, constraint := range constraints {
+			for _, constraint := range req.VersionConstraints {
 				rawConstraints = append(rawConstraints, constraint.Required...)
 			}
 			discoConstraints := discovery.NewConstraints(rawConstraints)

terraform/module_dependencies_test.go

@@ -3,7 +3,7 @@ package terraform
 import (
 	"testing"
 
-	"github.com/go-test/deep"
+	"github.com/google/go-cmp/cmp"
 
 	"github.com/hashicorp/terraform/configs"
 	"github.com/hashicorp/terraform/moduledeps"
@@ -52,6 +52,20 @@ func TestModuleTreeDependencies(t *testing.T) {
 				Children: nil,
 			},
 		},
+		"required_providers block": {
+			"module-deps-required-providers",
+			nil,
+			&moduledeps.Module{
+				Name: "root",
+				Providers: moduledeps.Providers{
+					"foo": moduledeps.ProviderDependency{
+						Constraints: discovery.ConstraintStr(">=1.0.0").MustParse(),
+						Reason:      moduledeps.ProviderDependencyExplicit,
+					},
+				},
+				Children: nil,
+			},
+		},
 		"explicit provider unconstrained": {
 			"module-deps-explicit-provider-unconstrained",
 			nil,
@@ -251,8 +265,8 @@ func TestModuleTreeDependencies(t *testing.T) {
 			}
 
 			got := ConfigTreeDependencies(root, MustShimLegacyState(test.State))
-			for _, problem := range deep.Equal(got, test.Want) {
-				t.Error(problem)
+			if !cmp.Equal(got, test.Want) {
+				t.Error(cmp.Diff(got, test.Want))
 			}
 		})
 	}

terraform/testdata/module-deps-required-providers/main.tf

@@ -0,0 +1,7 @@
+terraform {
+  required_providers {
+    foo = {
+      version = ">=1.0.0"
+    }
+  }
+}