getproviders: add a registry-specific error and modify output when a

provider is not found.

Previously a user would see the following error even if terraform was
only searching the local filesystem:

"provider registry registry.terraform.io does not have a provider named
...."

This PR adds a registry-specific error type and modifies the MultiSource
installer to check for registry errors. It will return the
registry-specific error message if there is one, but if not the error
message will list all locations searched.

command/013_config_upgrade.go

@@ -576,13 +576,12 @@ func (c *ZeroThirteenUpgradeCommand) detectProviderSources(requiredProviders map
 		if err == nil {
 			rp.Type = p
 		} else {
-			if _, ok := err.(getproviders.ErrProviderNotKnown); ok {
-				// Setting the provider address to a zero value struct
-				// indicates that there is no known FQN for this provider,
-				// which will cause us to write an explanatory comment in the
-				// HCL output advising the user what to do about this.
-				rp.Type = addrs.Provider{}
-			}
+			// Setting the provider address to a zero value struct
+			// indicates that there is no known FQN for this provider,
+			// which will cause us to write an explanatory comment in the
+			// HCL output advising the user what to do about this.
+			rp.Type = addrs.Provider{}
+
 			diags = diags.Append(tfdiags.Sourceless(
 				tfdiags.Warning,
 				"Could not detect provider source",

command/init.go

@@ -453,7 +453,7 @@ func (c *InitCommand) getProviders(earlyConfig *earlyconfig.Config, state *state
 
 		// The default (or configured) search paths are logged earlier, in provider_source.go
 		// Log that those are being overridden by the `-plugin-dir` command line options
-		log.Printf("[DEBUG] init: overriding provider plugin search paths")
+		log.Println("[DEBUG] init: overriding provider plugin search paths")
 		log.Printf("[DEBUG] will search for provider plugins in %s", pluginDirs)
 	}
 
@@ -495,11 +495,30 @@ func (c *InitCommand) getProviders(earlyConfig *earlyconfig.Config, state *state
 			c.Ui.Info(fmt.Sprintf("- Installing %s v%s...", provider.ForDisplay(), version))
 		},
 		QueryPackagesFailure: func(provider addrs.Provider, err error) {
-			diags = diags.Append(tfdiags.Sourceless(
-				tfdiags.Error,
-				"Failed to query available provider packages",
-				fmt.Sprintf("Could not retrieve the list of available versions for provider %s: %s.", provider.ForDisplay(), err),
-			))
+			switch errorTy := err.(type) {
+			case getproviders.ErrProviderNotFound:
+				sources := errorTy.Sources
+				displaySources := make([]string, len(sources))
+				for i, source := range sources {
+					displaySources[i] = fmt.Sprintf("- %s", source)
+				}
+				diags = diags.Append(tfdiags.Sourceless(
+					tfdiags.Error,
+					"Failed to query available provider packages",
+					fmt.Sprintf("Could not retrieve the list of available versions for provider %s: %s\n\n%s ",
+						provider.ForDisplay(), err, strings.Join(displaySources, "\n"),
+					),
+				))
+			default:
+				diags = diags.Append(tfdiags.Sourceless(
+					tfdiags.Error,
+					"Failed to query available provider packages",
+					fmt.Sprintf("Could not retrieve the list of available versions for provider %s: %s ",
+						provider.ForDisplay(), err,
+					),
+				))
+			}
+
 		},
 		LinkFromCacheFailure: func(provider addrs.Provider, version getproviders.Version, err error) {
 			diags = diags.Append(tfdiags.Sourceless(

internal/getproviders/errors.go

@@ -73,7 +73,22 @@ func (err ErrUnauthorized) Error() string {
 	}
 }
 
-// ErrProviderNotKnown is an error type used to indicate that the hostname
+// ErrProviderNotFound is an error type used to indicate that requested provider
+// was not found in the source(s) included in the Description field. This can be
+// used to produce user-friendly error messages.
+type ErrProviderNotFound struct {
+	Provider addrs.Provider
+	Sources  []string
+}
+
+func (err ErrProviderNotFound) Error() string {
+	return fmt.Sprintf(
+		"provider %s was not found in any of the search locations",
+		err.Provider,
+	)
+}
+
+// ErrRegistryProviderNotKnown is an error type used to indicate that the hostname
 // given in a provider address does appear to be a provider registry but that
 // registry does not know about the given provider namespace or type.
 //
@@ -85,11 +100,11 @@ func (err ErrUnauthorized) Error() string {
 // because we expect that the caller will have better context to decide what
 // hints are appropriate, e.g. by looking at the configuration given by the
 // user.
-type ErrProviderNotKnown struct {
+type ErrRegistryProviderNotKnown struct {
 	Provider addrs.Provider
 }
 
-func (err ErrProviderNotKnown) Error() string {
+func (err ErrRegistryProviderNotKnown) Error() string {
 	return fmt.Sprintf(
 		"provider registry %s does not have a provider named %s",
 		err.Provider.Hostname.ForDisplay(),
@@ -181,7 +196,7 @@ func (err ErrQueryFailed) Unwrap() error {
 // grow in future.
 func ErrIsNotExist(err error) bool {
 	switch err.(type) {
-	case ErrProviderNotKnown, ErrPlatformNotSupported:
+	case ErrProviderNotFound, ErrPlatformNotSupported:
 		return true
 	default:
 		return false

internal/getproviders/filesystem_mirror_source.go

@@ -120,3 +120,8 @@ func (s *FilesystemMirrorSource) scanAllVersions() error {
 	s.allPackages = ret
 	return nil
 }
+
+func (s *FilesystemMirrorSource) ForDisplay(provider addrs.Provider) string {
+	// TODO: Since we have the provider, this could show the entire search path
+	return s.baseDir
+}

internal/getproviders/http_mirror_source.go

@@ -35,3 +35,8 @@ func (s *HTTPMirrorSource) AvailableVersions(provider addrs.Provider) (VersionLi
 func (s *HTTPMirrorSource) PackageMeta(provider addrs.Provider, version Version, target Platform) (PackageMeta, error) {
 	return PackageMeta{}, fmt.Errorf("Network-based provider mirrors are not supported in this version of Terraform")
 }
+
+// ForDisplay returns a string description of the source for user-facing output.
+func (s *HTTPMirrorSource) ForDisplay(provider addrs.Provider) string {
+	return "Network-based provider mirrors are not supported in this version of Terraform"
+}

internal/getproviders/memoize_source.go

@@ -94,3 +94,7 @@ func (s *MemoizeSource) PackageMeta(provider addrs.Provider, version Version, ta
 	}
 	return ret, err
 }
+
+func (s *MemoizeSource) ForDisplay(provider addrs.Provider) string {
+	return s.underlying.ForDisplay(provider)
+}

internal/getproviders/memoize_source_test.go

@@ -39,7 +39,7 @@ func TestMemoizeSource(t *testing.T) {
 		}
 
 		_, err = source.AvailableVersions(nonexistProvider)
-		if want, ok := err.(ErrProviderNotKnown); !ok {
+		if want, ok := err.(ErrProviderNotFound); !ok {
 			t.Fatalf("wrong error type from nonexist call:\ngot:  %T\nwant: %T", err, want)
 		}
 
@@ -122,11 +122,11 @@ func TestMemoizeSource(t *testing.T) {
 		source := NewMemoizeSource(mock)
 
 		_, err := source.AvailableVersions(nonexistProvider)
-		if want, ok := err.(ErrProviderNotKnown); !ok {
+		if want, ok := err.(ErrProviderNotFound); !ok {
 			t.Fatalf("wrong error type from first call:\ngot:  %T\nwant: %T", err, want)
 		}
 		_, err = source.AvailableVersions(nonexistProvider)
-		if want, ok := err.(ErrProviderNotKnown); !ok {
+		if want, ok := err.(ErrProviderNotFound); !ok {
 			t.Fatalf("wrong error type from second call:\ngot:  %T\nwant: %T", err, want)
 		}
 

internal/getproviders/mock_source.go

@@ -51,7 +51,7 @@ func (s *MockSource) AvailableVersions(provider addrs.Provider) (VersionList, er
 	if len(ret) == 0 {
 		// In this case, we'll behave like a registry that doesn't know about
 		// this provider at all, rather than just returning an empty result.
-		return nil, ErrProviderNotKnown{provider}
+		return nil, ErrProviderNotFound{provider, []string{"mock source"}}
 	}
 	ret.Sort()
 	return ret, nil
@@ -198,3 +198,7 @@ func FakeInstallablePackageMeta(provider addrs.Provider, version Version, protoc
 	}
 	return meta, close, nil
 }
+
+func (s *MockSource) ForDisplay(provider addrs.Provider) string {
+	return "mock source"
+}

internal/getproviders/multi_source.go

@@ -36,6 +36,7 @@ func (s MultiSource) AvailableVersions(provider addrs.Provider) (VersionList, er
 	// We will return the union of all versions reported by the nested
 	// sources that have matching patterns that accept the given provider.
 	vs := make(map[Version]struct{})
+	var registryError bool
 	for _, selector := range s {
 		if !selector.CanHandleProvider(provider) {
 			continue // doesn't match the given patterns
@@ -43,8 +44,11 @@ func (s MultiSource) AvailableVersions(provider addrs.Provider) (VersionList, er
 		thisSourceVersions, err := selector.Source.AvailableVersions(provider)
 		switch err.(type) {
 		case nil:
-			// okay
-		case ErrProviderNotKnown:
+		// okay
+		case ErrRegistryProviderNotKnown:
+			registryError = true
+			continue // ignore, then
+		case ErrProviderNotFound:
 			continue // ignore, then
 		default:
 			return nil, err
@@ -55,7 +59,11 @@ func (s MultiSource) AvailableVersions(provider addrs.Provider) (VersionList, er
 	}
 
 	if len(vs) == 0 {
-		return nil, ErrProviderNotKnown{provider}
+		if registryError {
+			return nil, ErrRegistryProviderNotKnown{provider}
+		} else {
+			return nil, ErrProviderNotFound{provider, s.sourcesForProvider(provider)}
+		}
 	}
 	ret := make(VersionList, 0, len(vs))
 	for v := range vs {
@@ -70,7 +78,7 @@ func (s MultiSource) AvailableVersions(provider addrs.Provider) (VersionList, er
 // from the first selector that indicates availability of it.
 func (s MultiSource) PackageMeta(provider addrs.Provider, version Version, target Platform) (PackageMeta, error) {
 	if len(s) == 0 { // Easy case: no providers exist at all
-		return PackageMeta{}, ErrProviderNotKnown{provider}
+		return PackageMeta{}, ErrProviderNotFound{provider, s.sourcesForProvider(provider)}
 	}
 
 	for _, selector := range s {
@@ -81,7 +89,7 @@ func (s MultiSource) PackageMeta(provider addrs.Provider, version Version, targe
 		switch err.(type) {
 		case nil:
 			return meta, nil
-		case ErrProviderNotKnown, ErrPlatformNotSupported:
+		case ErrProviderNotFound, ErrRegistryProviderNotKnown, ErrPlatformNotSupported:
 			continue // ignore, then
 		default:
 			return PackageMeta{}, err
@@ -224,3 +232,20 @@ func normalizeProviderNameOrWildcard(s string) (string, error) {
 	}
 	return addrs.ParseProviderPart(s)
 }
+
+func (s MultiSource) ForDisplay(provider addrs.Provider) string {
+	return strings.Join(s.sourcesForProvider(provider), "\n")
+}
+
+// sourcesForProvider returns a list of source display strings configured for a
+// given provider, taking into account any `Exclude` statements.
+func (s MultiSource) sourcesForProvider(provider addrs.Provider) []string {
+	ret := make([]string, 0)
+	for _, selector := range s {
+		if !selector.CanHandleProvider(provider) {
+			continue // doesn't match the given patterns
+		}
+		ret = append(ret, selector.Source.ForDisplay(provider))
+	}
+	return ret
+}

internal/getproviders/multi_source_test.go

@@ -73,7 +73,7 @@ func TestMultiSourceAvailableVersions(t *testing.T) {
 		}
 
 		_, err = multi.AvailableVersions(addrs.NewDefaultProvider("baz"))
-		if want, ok := err.(ErrProviderNotKnown); !ok {
+		if want, ok := err.(ErrProviderNotFound); !ok {
 			t.Fatalf("wrong error type:\ngot:  %T\nwant: %T", err, want)
 		}
 	})
@@ -147,10 +147,32 @@ func TestMultiSourceAvailableVersions(t *testing.T) {
 		}
 
 		_, err = multi.AvailableVersions(addrs.NewDefaultProvider("baz"))
-		if want, ok := err.(ErrProviderNotKnown); !ok {
+		if want, ok := err.(ErrProviderNotFound); !ok {
 			t.Fatalf("wrong error type:\ngot:  %T\nwant: %T", err, want)
 		}
 	})
+
+	t.Run("provider not found", func(t *testing.T) {
+		s1 := NewMockSource(nil)
+		s2 := NewMockSource(nil)
+		multi := MultiSource{
+			{Source: s1},
+			{Source: s2},
+		}
+
+		_, err := multi.AvailableVersions(addrs.NewDefaultProvider("foo"))
+		if err == nil {
+			t.Fatal("expected error, got success")
+		}
+
+		wantErr := `provider registry.terraform.io/hashicorp/foo was not found in any of the search locations`
+		_ = []string{"mock source", "mock source"}
+
+		if err.Error() != wantErr {
+			t.Fatalf("wrong error.\ngot:  %s\nwant: %s\n", err, wantErr)
+		}
+
+	})
 }
 
 func TestMultiSourcePackageMeta(t *testing.T) {

internal/getproviders/registry_client.go

@@ -93,7 +93,7 @@ func newRegistryClient(baseURL *url.URL, creds svcauth.HostCredentials) *registr
 // ProviderVersions returns the raw version and protocol strings produced by the
 // registry for the given provider.
 //
-// The returned error will be ErrProviderNotKnown if the registry responds with
+// The returned error will be ErrRegistryProviderNotKnown if the registry responds with
 // 404 Not Found to indicate that the namespace or provider type are not known,
 // ErrUnauthorized if the registry responds with 401 or 403 status codes, or
 // ErrQueryFailed for any other protocol or operational problem.
@@ -122,7 +122,7 @@ func (c *registryClient) ProviderVersions(addr addrs.Provider) (map[string][]str
 	case http.StatusOK:
 		// Great!
 	case http.StatusNotFound:
-		return nil, ErrProviderNotKnown{
+		return nil, ErrRegistryProviderNotKnown{
 			Provider: addr,
 		}
 	case http.StatusUnauthorized, http.StatusForbidden:
@@ -357,7 +357,6 @@ func (c *registryClient) PackageMeta(provider addrs.Provider, version Version, t
 	return ret, nil
 }
 
-// LegacyProviderDefaultNamespace returns the raw address strings produced by
 // findClosestProtocolCompatibleVersion searches for the provider version with the closest protocol match.
 func (c *registryClient) findClosestProtocolCompatibleVersion(provider addrs.Provider, version Version) (Version, error) {
 	var match Version
@@ -401,7 +400,7 @@ FindMatch:
 	return match, nil
 }
 
-// LegacyProviderCanonicalAddress returns the raw address strings produced by
+// LegacyProviderDefaultNamespace returns the raw address strings produced by
 // the registry when asked about the given unqualified provider type name.
 // The returned namespace string is taken verbatim from the registry's response.
 //
@@ -437,7 +436,7 @@ func (c *registryClient) LegacyProviderDefaultNamespace(typeName string) (string
 	case http.StatusOK:
 		// Great!
 	case http.StatusNotFound:
-		return "", ErrProviderNotKnown{
+		return "", ErrProviderNotFound{
 			Provider: placeholderProviderAddr,
 		}
 	case http.StatusUnauthorized, http.StatusForbidden:

internal/getproviders/registry_source.go

@@ -167,3 +167,7 @@ func (s *RegistrySource) registryClient(hostname svchost.Hostname) (*registryCli
 
 	return newRegistryClient(url, creds), nil
 }
+
+func (s *RegistrySource) ForDisplay(provider addrs.Provider) string {
+	return fmt.Sprintf("registry %s", provider.Hostname.ForDisplay())
+}

internal/getproviders/source.go

@@ -9,4 +9,5 @@ import (
 type Source interface {
 	AvailableVersions(provider addrs.Provider) (VersionList, error)
 	PackageMeta(provider addrs.Provider, version Version, target Platform) (PackageMeta, error)
+	ForDisplay(provider addrs.Provider) string
 }