Merge pull request #25191 from hashicorp/alisdair/better-provider-upgrade-hints-on-init

command/init: Improve diags for legacy providers

command/init.go

@@ -607,6 +607,12 @@ func (c *InitCommand) getProviders(config *configs.Config, state *states.State,
 	ctx := evts.OnContext(context.TODO())
 	selected, err := inst.EnsureProviderVersions(ctx, reqs, mode)
 	if err != nil {
+		// Build a map of provider address to modules using the provider,
+		// so that we can later show diagnostics about affected modules
+		reqs, _ := config.ProviderRequirementsByModule()
+		providerToReqs := make(map[addrs.Provider][]*configs.ModuleRequirements)
+		c.populateProviderToReqs(providerToReqs, reqs)
+
 		// Try to look up any missing providers which may be redirected legacy
 		// providers. If we're successful, construct a "did you mean?" diag to
 		// suggest how to fix this. Otherwise, add a simple error diag
@@ -627,14 +633,63 @@ func (c *InitCommand) getProviders(config *configs.Config, state *states.State,
 			}
 		}
 		if len(foundProviders) > 0 {
+			// Build list of provider suggestions, and track a list of local
+			// and remote modules which need to be upgraded
 			var providerSuggestions string
+			localModules := make(map[string]struct{})
+			remoteModules := make(map[*configs.ModuleRequirements]struct{})
 			for missingProvider, foundProvider := range foundProviders {
 				providerSuggestions += fmt.Sprintf("  %s -> %s\n", missingProvider.ForDisplay(), foundProvider.ForDisplay())
+				exists := struct{}{}
+				for _, reqs := range providerToReqs[missingProvider] {
+					src := reqs.SourceAddr
+					// Treat the root module and any others with local source
+					// addresses as fixable with 0.13upgrade. Remote modules
+					// must be upgraded elsewhere and therefore are listed
+					// separately
+					if src == "" || isLocalSourceAddr(src) {
+						localModules[reqs.SourceDir] = exists
+					} else {
+						remoteModules[reqs] = exists
+					}
+				}
 			}
+
+			// Create sorted list of 0.13upgrade commands with the affected
+			// source dirs
+			var upgradeCommands []string
+			for dir := range localModules {
+				upgradeCommands = append(upgradeCommands, fmt.Sprintf("terraform 0.13upgrade %s", dir))
+			}
+			sort.Strings(upgradeCommands)
+			command := "command"
+			if len(upgradeCommands) > 1 {
+				command = "commands"
+			}
+
+			// Display detailed diagnostic results, including the missing and
+			// found provider FQNs, and the suggested series of upgrade
+			// commands to fix this
+			var detail strings.Builder
+
+			fmt.Fprintf(&detail, "Could not find required providers, but found possible alternatives:\n\n%s\n", providerSuggestions)
+
+			fmt.Fprintf(&detail, "If these suggestions look correct, upgrade your configuration with the following %s:", command)
+			for _, upgradeCommand := range upgradeCommands {
+				fmt.Fprintf(&detail, "\n    %s", upgradeCommand)
+			}
+
+			if len(remoteModules) > 0 {
+				fmt.Fprintf(&detail, "\n\nThe following remote modules must also be upgraded for Terraform 0.13 compatibility:")
+				for remoteModule := range remoteModules {
+					fmt.Fprintf(&detail, "\n- module.%s at %s", remoteModule.Name, remoteModule.SourceAddr)
+				}
+			}
+
 			diags = diags.Append(tfdiags.Sourceless(
 				tfdiags.Error,
 				"Failed to install providers",
-				fmt.Sprintf("Could not find required providers, but found possible alternatives:\n\n%s\nIf these suggestions look correct, upgrade your configuration with the following command:\n    terraform 0.13upgrade", providerSuggestions),
+				detail.String(),
 			))
 		}
 
@@ -675,6 +730,16 @@ func (c *InitCommand) getProviders(config *configs.Config, state *states.State,
 	return true, diags
 }
 
+func (c *InitCommand) populateProviderToReqs(reqs map[addrs.Provider][]*configs.ModuleRequirements, node *configs.ModuleRequirements) {
+	for fqn := range node.Requirements {
+		reqs[fqn] = append(reqs[fqn], node)
+	}
+
+	for _, child := range node.Children {
+		c.populateProviderToReqs(reqs, child)
+	}
+}
+
 // backendConfigOverrideBody interprets the raw values of -backend-config
 // arguments into a hcl Body that should override the backend settings given
 // in the configuration.
@@ -1045,3 +1110,20 @@ Alternatively, upgrade to the latest version of Terraform for compatibility with
 
 // No version of the provider is compatible.
 const errProviderVersionIncompatible = `No compatible versions of provider %s were found.`
+
+// Logic from internal/initwd/getter.go
+var localSourcePrefixes = []string{
+	"./",
+	"../",
+	".\\",
+	"..\\",
+}
+
+func isLocalSourceAddr(addr string) bool {
+	for _, prefix := range localSourcePrefixes {
+		if strings.HasPrefix(addr, prefix) {
+			return true
+		}
+	}
+	return false
+}

command/init_test.go

@@ -951,14 +951,19 @@ func TestInit_getProviderDetectedLegacy(t *testing.T) {
 
 	// error output is the main focus of this test
 	errOutput := ui.ErrorWriter.String()
-	if !strings.Contains(errOutput, "Error while installing hashicorp/frob:") {
+	errors := []string{
-		t.Fatalf("expected error for installing hashicorp/frob: %s", errOutput)
+		"Error while installing hashicorp/frob:",
+		"Could not find required providers, but found possible alternatives",
+		"hashicorp/baz -> terraform-providers/baz",
+		"terraform 0.13upgrade .",
+		"terraform 0.13upgrade child",
+		"The following remote modules must also be upgraded",
+		"- module.dicerolls at acme/bar/random",
 	}
-	if !strings.Contains(errOutput, "Could not find required providers, but found possible alternatives") {
+	for _, want := range errors {
-		t.Fatalf("expected required provider suggestions: %s", errOutput)
+		if !strings.Contains(errOutput, want) {
-	}
+			t.Fatalf("expected error %q: %s", want, errOutput)
-	if !strings.Contains(errOutput, "hashicorp/baz -> terraform-providers/baz") {
+		}
-		t.Fatalf("expected suggestion for hashicorp/baz: %s", errOutput)
 	}
 }
 

command/testdata/init-get-provider-detected-legacy/.terraform/modules/dicerolls/terraform-random-bar-1.0.0/main.tf

@@ -0,0 +1,7 @@
+// This will try to install hashicorp/baz, fail, and then suggest
+// terraform-providers/baz
+provider baz {}
+
+output "d6" {
+  value = 4 // chosen by fair dice roll, guaranteed to be random
+}

command/testdata/init-get-provider-detected-legacy/.terraform/modules/modules.json

@@ -0,0 +1 @@
+{"Modules":[{"Key":"dicerolls","Source":"acme/bar/random","Version":"1.0.0","Dir":".terraform/modules/dicerolls/terraform-random-bar-1.0.0"},{"Key":"","Source":"","Dir":"."}]}

command/testdata/init-get-provider-detected-legacy/child/main.tf

@@ -0,0 +1,3 @@
+// This will try to install hashicorp/baz, fail, and then suggest
+// terraform-providers/baz
+provider baz {}

command/testdata/init-get-provider-detected-legacy/main.tf

@@ -8,3 +8,11 @@ provider baz {}
 // This will try to install hashicrop/frob, fail, find no suggestions, and
 // result in an error
 provider frob {}
+
+module "some-baz-stuff" {
+  source = "./child"
+}
+
+module "dicerolls" {
+  source = "acme/bar/random"
+}

configs/config.go

@@ -81,7 +81,9 @@ type Config struct {
 // module, along with references to any child modules. This is used to
 // determine which modules require which providers.
 type ModuleRequirements struct {
-	Module       *Module
+	Name         string
+	SourceAddr   string
+	SourceDir    string
 	Requirements getproviders.Requirements
 	Children     map[string]*ModuleRequirements
 }
@@ -206,12 +208,14 @@ func (c *Config) ProviderRequirementsByModule() (*ModuleRequirements, hcl.Diagno
 	children := make(map[string]*ModuleRequirements)
 	for name, child := range c.Children {
 		childReqs, childDiags := child.ProviderRequirementsByModule()
+		childReqs.Name = name
 		children[name] = childReqs
 		diags = append(diags, childDiags...)
 	}
 
 	ret := &ModuleRequirements{
-		Module:       c.Module,
+		SourceAddr:   c.SourceAddr,
+		SourceDir:    c.Module.SourceDir,
 		Requirements: reqs,
 		Children:     children,
 	}

configs/config_test.go

@@ -169,12 +169,10 @@ func TestConfigProviderRequirementsByModule(t *testing.T) {
 
 	got, diags := cfg.ProviderRequirementsByModule()
 	assertNoDiagnostics(t, diags)
-	child, ok := cfg.Children["kinder"]
-	if !ok {
-		t.Fatalf(`could not find child config "kinder" in config children`)
-	}
 	want := &ModuleRequirements{
-		Module: cfg.Module,
+		Name:       "",
+		SourceAddr: "",
+		SourceDir:  "testdata/provider-reqs",
 		Requirements: getproviders.Requirements{
 			// Only the root module's version is present here
 			nullProvider:       getproviders.MustParseVersionConstraints("~> 2.0.0"),
@@ -186,7 +184,9 @@ func TestConfigProviderRequirementsByModule(t *testing.T) {
 		},
 		Children: map[string]*ModuleRequirements{
 			"kinder": {
-				Module: child.Module,
+				Name:       "kinder",
+				SourceAddr: "./child",
+				SourceDir:  "testdata/provider-reqs/child",
 				Requirements: getproviders.Requirements{
 					nullProvider:       getproviders.MustParseVersionConstraints("= 2.0.1"),
 					happycloudProvider: nil,