cleanup: move caching resolvers from netx to netxlite (#799)

Now that we have properly refactored the caching resolvers we can move them into netxlite as optional resolvers created using the proper abstract factories we just added. This diff reduces the complexity and the code size of netx. See ooni/probe#2121.
ooni · Jun 5, 2022 · 5d54aa9 · 5d54aa9
1 parent 6b85dfc
commit 5d54aa9
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Showing 5 changed files with 34 additions and 36 deletions.
diff --git a/internal/engine/netx/netx.go b/internal/engine/netx/netx.go
@@ -67,8 +67,8 @@ func NewResolver(config Config) model.Resolver {
 		model.ValidLoggerOrDefault(config.Logger),
 		config.BaseResolver,
 	)
-	r = MaybeWrapWithCachingResolver(config.CacheResolutions, r)
-	r = MaybeWrapWithStaticDNSCache(config.DNSCache, r)
+	r = netxlite.MaybeWrapWithCachingResolver(config.CacheResolutions, r)
+	r = netxlite.MaybeWrapWithStaticDNSCache(config.DNSCache, r)
 	r = netxlite.MaybeWrapWithBogonResolver(config.BogonIsError, r)
 	return config.Saver.WrapResolver(r) // WAI when config.Saver==nil
 }

diff --git a/internal/netxlite/bogon.go b/internal/netxlite/bogon.go
@@ -3,7 +3,8 @@ package netxlite
 //
 // Bogon
 //
-// This file helps us to decide if an IPAddr is a bogon.
+// This file helps us to decide if an IPAddr is a bogon as well as
+// a way to create a resolver that fails when resolving bogons.
 //
 
 import (
@@ -17,29 +18,28 @@ import (
 // MaybeWrapWithBogonResolver wraps the given resolver with a BogonResolver
 // iff the provided boolean flag is true. Otherwise, this factory just returns
 // the provided resolver to the caller without any wrapping.
+//
+// The returned resolver returns a wrapped ErrDNSBogon if there's a bogon error.
+//
+// BUG: This resolver currently only implements LookupHost. All the other
+// lookup methods will always return ErrNoDNSTransport.
 func MaybeWrapWithBogonResolver(enabled bool, reso model.Resolver) model.Resolver {
 	if enabled {
-		reso = &BogonResolver{Resolver: reso}
+		reso = &bogonResolver{Resolver: reso}
 	}
 	return reso
 }
 
-// BogonResolver is a bogon aware resolver. When a bogon is encountered in
+// bogonResolver is a bogon aware resolver. When a bogon is encountered in
 // a reply, this resolver will return ErrDNSBogon.
-//
-// This resolver is not part of the default chain created by WrapResolver
-// therefore it returns errors that have already been wrapped.
-//
-// BUG: This resolver currently only implements LookupHost. All the other
-// lookup methods will always return ErrNoDNSTransport.
-type BogonResolver struct {
+type bogonResolver struct {
 	Resolver model.Resolver
 }
 
-var _ model.Resolver = &BogonResolver{}
+var _ model.Resolver = &bogonResolver{}
 
 // LookupHost implements Resolver.LookupHost
-func (r *BogonResolver) LookupHost(ctx context.Context, hostname string) ([]string, error) {
+func (r *bogonResolver) LookupHost(ctx context.Context, hostname string) ([]string, error) {
 	addrs, err := r.Resolver.LookupHost(ctx, hostname)
 	if err != nil {
 		return nil, err // not our responsibility to wrap this error
@@ -54,29 +54,29 @@ func (r *BogonResolver) LookupHost(ctx context.Context, hostname string) ([]stri
 }
 
 // LookupHTTPS implements Resolver.LookupHTTPS
-func (r *BogonResolver) LookupHTTPS(ctx context.Context, hostname string) (*model.HTTPSSvc, error) {
+func (r *bogonResolver) LookupHTTPS(ctx context.Context, hostname string) (*model.HTTPSSvc, error) {
 	// TODO(bassosimone): decide whether we want to implement this method or not
 	return nil, ErrNoDNSTransport
 }
 
 // LookupNS implements Resolver.LookupNS
-func (r *BogonResolver) LookupNS(ctx context.Context, hostname string) ([]*net.NS, error) {
+func (r *bogonResolver) LookupNS(ctx context.Context, hostname string) ([]*net.NS, error) {
 	// TODO(bassosimone): decide whether we want to implement this method or not
 	return nil, ErrNoDNSTransport
 }
 
 // Network implements Resolver.Network
-func (r *BogonResolver) Network() string {
+func (r *bogonResolver) Network() string {
 	return r.Resolver.Network()
 }
 
 // Address implements Resolver.Address
-func (r *BogonResolver) Address() string {
+func (r *bogonResolver) Address() string {
 	return r.Resolver.Address()
 }
 
 // CloseIdleConnections implements Resolver.CloseIdleConnections
-func (r *BogonResolver) CloseIdleConnections() {
+func (r *bogonResolver) CloseIdleConnections() {
 	r.Resolver.CloseIdleConnections()
 }
 

diff --git a/internal/netxlite/bogon_test.go b/internal/netxlite/bogon_test.go
@@ -13,7 +13,7 @@ func TestMaybeWrapWithBogonResolver(t *testing.T) {
 	t.Run("with enabled equal to true", func(t *testing.T) {
 		underlying := &mocks.Resolver{}
 		reso := MaybeWrapWithBogonResolver(true, underlying)
-		bogoreso := reso.(*BogonResolver)
+		bogoreso := reso.(*bogonResolver)
 		if bogoreso.Resolver != underlying {
 			t.Fatal("did not wrap")
 		}
@@ -32,7 +32,7 @@ func TestBogonResolver(t *testing.T) {
 	t.Run("LookupHost", func(t *testing.T) {
 		t.Run("with failure", func(t *testing.T) {
 			expected := errors.New("mocked")
-			reso := &BogonResolver{
+			reso := &bogonResolver{
 				Resolver: &mocks.Resolver{
 					MockLookupHost: func(ctx context.Context, domain string) ([]string, error) {
 						return nil, expected
@@ -51,7 +51,7 @@ func TestBogonResolver(t *testing.T) {
 
 		t.Run("with success and no bogon", func(t *testing.T) {
 			expected := []string{"8.8.8.8", "149.112.112.112"}
-			reso := &BogonResolver{
+			reso := &bogonResolver{
 				Resolver: &mocks.Resolver{
 					MockLookupHost: func(ctx context.Context, domain string) ([]string, error) {
 						return expected, nil
@@ -69,7 +69,7 @@ func TestBogonResolver(t *testing.T) {
 		})
 
 		t.Run("with success and bogon", func(t *testing.T) {
-			reso := &BogonResolver{
+			reso := &bogonResolver{
 				Resolver: &mocks.Resolver{
 					MockLookupHost: func(ctx context.Context, domain string) ([]string, error) {
 						return []string{"8.8.8.8", "10.34.34.35", "149.112.112.112"}, nil
@@ -93,7 +93,7 @@ func TestBogonResolver(t *testing.T) {
 
 	t.Run("LookupHTTPS", func(t *testing.T) {
 		ctx := context.Background()
-		reso := &BogonResolver{}
+		reso := &bogonResolver{}
 		https, err := reso.LookupHTTPS(ctx, "dns.google")
 		if !errors.Is(err, ErrNoDNSTransport) {
 			t.Fatal("unexpected err", err)
@@ -105,7 +105,7 @@ func TestBogonResolver(t *testing.T) {
 
 	t.Run("LookupNS", func(t *testing.T) {
 		ctx := context.Background()
-		reso := &BogonResolver{}
+		reso := &bogonResolver{}
 		ns, err := reso.LookupNS(ctx, "dns.google")
 		if !errors.Is(err, ErrNoDNSTransport) {
 			t.Fatal("unexpected err", err)
@@ -117,7 +117,7 @@ func TestBogonResolver(t *testing.T) {
 
 	t.Run("Network", func(t *testing.T) {
 		expected := "antani"
-		reso := &BogonResolver{
+		reso := &bogonResolver{
 			Resolver: &mocks.Resolver{
 				MockNetwork: func() string {
 					return expected
@@ -131,7 +131,7 @@ func TestBogonResolver(t *testing.T) {
 
 	t.Run("Address", func(t *testing.T) {
 		expected := "antani"
-		reso := &BogonResolver{
+		reso := &bogonResolver{
 			Resolver: &mocks.Resolver{
 				MockAddress: func() string {
 					return expected
@@ -145,7 +145,7 @@ func TestBogonResolver(t *testing.T) {
 
 	t.Run("CloseIdleConnections", func(t *testing.T) {
 		var called bool
-		reso := &BogonResolver{
+		reso := &bogonResolver{
 			Resolver: &mocks.Resolver{
 				MockCloseIdleConnections: func() {
 					called = true

diff --git a/internal/engine/netx/cacheresolver.go → internal/netxlite/resolvercache.go b/internal/engine/netx/cacheresolver.go → internal/netxlite/resolvercache.go
@@ -1,12 +1,11 @@
-package netx
+package netxlite
 
 import (
 	"context"
 	"net"
 	"sync"
 
 	"github.com/ooni/probe-cli/v3/internal/model"
-	"github.com/ooni/probe-cli/v3/internal/netxlite"
 )
 
 // MaybeWrapWithCachingResolver wraps the provided resolver with a resolver
@@ -111,10 +110,10 @@ func (r *cacheResolver) CloseIdleConnections() {
 
 // LookupHTTPS implements model.Resolver.LookupHTTPS.
 func (r *cacheResolver) LookupHTTPS(ctx context.Context, domain string) (*model.HTTPSSvc, error) {
-	return nil, netxlite.ErrNoDNSTransport
+	return nil, ErrNoDNSTransport
 }
 
 // LookupNS implements model.Resolver.LookupNS.
 func (r *cacheResolver) LookupNS(ctx context.Context, domain string) ([]*net.NS, error) {
-	return nil, netxlite.ErrNoDNSTransport
+	return nil, ErrNoDNSTransport
 }
diff --git a/internal/engine/netx/cacheresolver_test.go → internal/netxlite/resolvercache_test.go b/internal/engine/netx/cacheresolver_test.go → internal/netxlite/resolvercache_test.go
@@ -1,4 +1,4 @@
-package netx
+package netxlite
 
 import (
 	"context"
@@ -7,7 +7,6 @@ import (
 
 	"github.com/google/go-cmp/cmp"
 	"github.com/ooni/probe-cli/v3/internal/model/mocks"
-	"github.com/ooni/probe-cli/v3/internal/netxlite"
 )
 
 func TestMaybeWrapWithCachingResolver(t *testing.T) {
@@ -184,7 +183,7 @@ func TestCacheResolver(t *testing.T) {
 		t.Run("LookupHTTPS", func(t *testing.T) {
 			reso := &cacheResolver{}
 			https, err := reso.LookupHTTPS(context.Background(), "dns.google")
-			if !errors.Is(err, netxlite.ErrNoDNSTransport) {
+			if !errors.Is(err, ErrNoDNSTransport) {
 				t.Fatal("unexpected err", err)
 			}
 			if https != nil {
@@ -195,7 +194,7 @@ func TestCacheResolver(t *testing.T) {
 		t.Run("LookupNS", func(t *testing.T) {
 			reso := &cacheResolver{}
 			ns, err := reso.LookupNS(context.Background(), "dns.google")
-			if !errors.Is(err, netxlite.ErrNoDNSTransport) {
+			if !errors.Is(err, ErrNoDNSTransport) {
 				t.Fatal("unexpected err", err)
 			}
 			if len(ns) != 0 {