rename all remaining packages to internal/ (#12418)

This is to ensure that there are no projects
that try to import `minio/minio/pkg` into
their own repo. Any such common packages should
go to `https://github.com/minio/pkg`

internal/http/dial_dnscache_test.go

@@ -0,0 +1,209 @@
+// Copyright (c) 2015-2021 MinIO, Inc.
+//
+// This file is part of MinIO Object Storage stack
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package http
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"math/rand"
+	"net"
+	"testing"
+	"time"
+)
+
+var (
+	testFreq                 = 1 * time.Second
+	testDefaultLookupTimeout = 1 * time.Second
+)
+
+func logOnce(ctx context.Context, err error, id interface{}, errKind ...interface{}) {
+	// no-op
+}
+
+func testDNSCache(t *testing.T) *DNSCache {
+	t.Helper() // skip printing file and line information from this function
+	return NewDNSCache(testFreq, testDefaultLookupTimeout, logOnce)
+}
+
+func TestDialContextWithDNSCache(t *testing.T) {
+	resolver := &DNSCache{
+		cache: map[string][]string{
+			"play.min.io": {
+				"127.0.0.1",
+				"127.0.0.2",
+				"127.0.0.3",
+			},
+		},
+	}
+
+	cases := []struct {
+		permF func(n int) []int
+		dialF DialContext
+	}{
+		{
+			permF: func(n int) []int {
+				return []int{0}
+			},
+			dialF: func(ctx context.Context, network, addr string) (net.Conn, error) {
+				if got, want := addr, net.JoinHostPort("127.0.0.1", "443"); got != want {
+					t.Fatalf("got addr %q, want %q", got, want)
+				}
+				return nil, nil
+			},
+		},
+		{
+			permF: func(n int) []int {
+				return []int{1}
+			},
+			dialF: func(ctx context.Context, network, addr string) (net.Conn, error) {
+				if got, want := addr, net.JoinHostPort("127.0.0.2", "443"); got != want {
+					t.Fatalf("got addr %q, want %q", got, want)
+				}
+				return nil, nil
+			},
+		},
+		{
+			permF: func(n int) []int {
+				return []int{2}
+			},
+			dialF: func(ctx context.Context, network, addr string) (net.Conn, error) {
+				if got, want := addr, net.JoinHostPort("127.0.0.3", "443"); got != want {
+					t.Fatalf("got addr %q, want %q", got, want)
+				}
+				return nil, nil
+			},
+		},
+	}
+
+	origFunc := randPerm
+	defer func() {
+		randPerm = origFunc
+	}()
+
+	for _, tc := range cases {
+		t.Run("", func(t *testing.T) {
+			randPerm = tc.permF
+			if _, err := DialContextWithDNSCache(resolver, tc.dialF)(context.Background(), "tcp", "play.min.io:443"); err != nil {
+				t.Fatalf("err: %s", err)
+			}
+		})
+	}
+
+}
+
+func TestDialContextWithDNSCacheRand(t *testing.T) {
+	rand.Seed(time.Now().UTC().UnixNano())
+	defer func() {
+		rand.Seed(1)
+	}()
+
+	resolver := &DNSCache{
+		cache: map[string][]string{
+			"play.min.io": {
+				"127.0.0.1",
+				"127.0.0.2",
+				"127.0.0.3",
+			},
+		},
+	}
+
+	count := make(map[string]int)
+	dialF := func(ctx context.Context, network, addr string) (net.Conn, error) {
+		count[addr]++
+		return nil, nil
+	}
+
+	for i := 0; i < 100; i++ {
+		if _, err := DialContextWithDNSCache(resolver, dialF)(context.Background(), "tcp", "play.min.io:443"); err != nil {
+			t.Fatalf("err: %s", err)
+		}
+	}
+
+	for _, c := range count {
+		got := float32(c) / float32(100)
+		if got < float32(0.1) {
+			t.Fatalf("expected 0.1 rate got %f", got)
+		}
+	}
+}
+
+// Verify without port Dial fails, Go stdlib net.Dial expects port
+func TestDialContextWithDNSCacheScenario1(t *testing.T) {
+	resolver := testDNSCache(t)
+	if _, err := DialContextWithDNSCache(resolver, nil)(context.Background(), "tcp", "play.min.io"); err == nil {
+		t.Fatalf("expect to fail") // expected port
+	}
+}
+
+// Verify if the host lookup function failed to return addresses
+func TestDialContextWithDNSCacheScenario2(t *testing.T) {
+	res := testDNSCache(t)
+	originalFunc := res.lookupHostFn
+	defer func() {
+		res.lookupHostFn = originalFunc
+	}()
+
+	res.lookupHostFn = func(ctx context.Context, host string) ([]string, error) {
+		return nil, fmt.Errorf("err")
+	}
+
+	if _, err := DialContextWithDNSCache(res, nil)(context.Background(), "tcp", "min.io:443"); err == nil {
+		t.Fatalf("exect to fail")
+	}
+}
+
+// Verify we always return the first error from net.Dial failure
+func TestDialContextWithDNSCacheScenario3(t *testing.T) {
+	resolver := &DNSCache{
+		cache: map[string][]string{
+			"min.io": {
+				"1.1.1.1",
+				"2.2.2.2",
+				"3.3.3.3",
+			},
+		},
+	}
+
+	origFunc := randPerm
+	randPerm = func(n int) []int {
+		return []int{0, 1, 2}
+	}
+	defer func() {
+		randPerm = origFunc
+	}()
+
+	want := errors.New("error1")
+	dialF := func(ctx context.Context, network, addr string) (net.Conn, error) {
+		if addr == net.JoinHostPort("1.1.1.1", "443") {
+			return nil, want // first error should be returned
+		}
+		if addr == net.JoinHostPort("2.2.2.2", "443") {
+			return nil, fmt.Errorf("error2")
+		}
+		if addr == net.JoinHostPort("3.3.3.3", "443") {
+			return nil, fmt.Errorf("error3")
+		}
+		return nil, nil
+	}
+
+	_, got := DialContextWithDNSCache(resolver, dialF)(context.Background(), "tcp", "min.io:443")
+	if got != want {
+		t.Fatalf("got error %v, want %v", got, want)
+	}
+}