实现爬虫检测中间件 (#22)

* feat(crawlerdetect): 实现爬虫检测中间件

* feat(crawlerdetect):
- 添加 license
- 测试代码优化

* feat(crawlerdetect): 修复 license

internal/crawlerdetect/baidu_strategy.go

@@ -0,0 +1,25 @@
+// Copyright 2023 ecodeclub
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package crawlerdetect
+
+type BaiduStrategy struct {
+	*UniversalStrategy
+}
+
+func NewBaiduStrategy() *BaiduStrategy {
+	return &BaiduStrategy{
+		UniversalStrategy: NewUniversalStrategy([]string{"baidu.com", "baidu.jp"}),
+	}
+}

internal/crawlerdetect/baidu_strategy_test.go

@@ -0,0 +1,67 @@
+// Copyright 2023 ecodeclub
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package crawlerdetect
+
+import (
+	"errors"
+	"log"
+	"net"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestBaiduStrategy(t *testing.T) {
+	s := NewBaiduStrategy()
+	require.NotNil(t, s)
+	testCases := []struct {
+		name    string
+		ip      string
+		matched bool
+		errFunc require.ErrorAssertionFunc
+	}{
+		{
+			name:    "无效 ip",
+			ip:      "256.0.0.0",
+			matched: false,
+			errFunc: func(t require.TestingT, err error, i ...interface{}) {
+				var dnsError *net.DNSError
+				if !errors.As(err, &dnsError) {
+					log.Fatal(err)
+				}
+			},
+		},
+		{
+			name:    "非百度 ip",
+			ip:      "166.249.90.77",
+			matched: false,
+		},
+		{
+			name:    "百度 ip",
+			ip:      "111.206.198.69",
+			matched: true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			m, err := s.CheckCrawler(tc.ip)
+			if err != nil {
+				tc.errFunc(t, err)
+			}
+			require.Equal(t, tc.matched, m)
+		})
+	}
+}

internal/crawlerdetect/bing_strategy.go

@@ -0,0 +1,25 @@
+// Copyright 2023 ecodeclub
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package crawlerdetect
+
+type BingStrategy struct {
+	*UniversalStrategy
+}
+
+func NewBingStrategy() *BingStrategy {
+	return &BingStrategy{
+		UniversalStrategy: NewUniversalStrategy([]string{"search.msn.com"}),
+	}
+}

internal/crawlerdetect/bing_strategy_test.go

@@ -0,0 +1,67 @@
+// Copyright 2023 ecodeclub
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package crawlerdetect
+
+import (
+	"errors"
+	"log"
+	"net"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestBingStrategy(t *testing.T) {
+	s := NewBingStrategy()
+	require.NotNil(t, s)
+	testCases := []struct {
+		name    string
+		ip      string
+		matched bool
+		errFunc require.ErrorAssertionFunc
+	}{
+		{
+			name:    "无效 ip",
+			ip:      "256.0.0.0",
+			matched: false,
+			errFunc: func(t require.TestingT, err error, i ...interface{}) {
+				var dnsError *net.DNSError
+				if !errors.As(err, &dnsError) {
+					log.Fatal(err)
+				}
+			},
+		},
+		{
+			name:    "非必应 ip",
+			ip:      "166.249.90.77",
+			matched: false,
+		},
+		{
+			name:    "必应 ip",
+			ip:      "157.55.39.1",
+			matched: true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			m, err := s.CheckCrawler(tc.ip)
+			if err != nil {
+				tc.errFunc(t, err)
+			}
+			require.Equal(t, tc.matched, m)
+		})
+	}
+}

internal/crawlerdetect/crawler_detector.go

@@ -0,0 +1,93 @@
+// Copyright 2023 ecodeclub
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package crawlerdetect
+
+import (
+	"net"
+	"slices"
+	"strings"
+)
+
+const (
+	Baidu  = "baidu"
+	Bing   = "bing"
+	Google = "google"
+	Sogou  = "sogou"
+)
+
+var strategyMap = map[string]Strategy{
+	Baidu:  NewBaiduStrategy(),
+	Bing:   NewBingStrategy(),
+	Google: NewGoogleStrategy(),
+	Sogou:  NewSoGouStrategy(),
+}
+
+type Strategy interface {
+	CheckCrawler(ip string) (bool, error)
+}
+
+type UniversalStrategy struct {
+	Hosts []string
+}
+
+func NewUniversalStrategy(hosts []string) *UniversalStrategy {
+	return &UniversalStrategy{
+		Hosts: hosts,
+	}
+}
+
+func (s *UniversalStrategy) CheckCrawler(ip string) (bool, error) {
+	names, err := net.LookupAddr(ip)
+	if err != nil {
+		return false, err
+	}
+	if len(names) == 0 {
+		return false, nil
+	}
+
+	name, matched := s.matchHost(names)
+	if !matched {
+		return false, nil
+	}
+
+	ips, err := net.LookupIP(name)
+	if err != nil {
+		return false, err
+	}
+	if slices.ContainsFunc(ips, func(netIp net.IP) bool {
+		return netIp.String() == ip
+	}) {
+		return true, nil
+	}
+
+	return false, nil
+}
+
+func (s *UniversalStrategy) matchHost(names []string) (string, bool) {
+	var matchedName string
+	return matchedName, slices.ContainsFunc(s.Hosts, func(host string) bool {
+		return slices.ContainsFunc(names, func(name string) bool {
+			if strings.Contains(name, host) {
+				matchedName = name
+				return true
+			}
+			return false
+		})
+	})
+}
+
+func NewCrawlerDetector(crawler string) Strategy {
+	return strategyMap[crawler]
+}

internal/crawlerdetect/google_strategy.go

@@ -0,0 +1,25 @@
+// Copyright 2023 ecodeclub
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package crawlerdetect
+
+type GoogleStrategy struct {
+	*UniversalStrategy
+}
+
+func NewGoogleStrategy() *GoogleStrategy {
+	return &GoogleStrategy{
+		UniversalStrategy: NewUniversalStrategy([]string{"googlebot.com", "google.com", "googleusercontent.com"}),
+	}
+}

internal/crawlerdetect/google_strategy_test.go

@@ -0,0 +1,67 @@
+// Copyright 2023 ecodeclub
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package crawlerdetect
+
+import (
+	"errors"
+	"log"
+	"net"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestGoogleStrategy(t *testing.T) {
+	s := NewGoogleStrategy()
+	require.NotNil(t, s)
+	testCases := []struct {
+		name    string
+		ip      string
+		matched bool
+		errFunc require.ErrorAssertionFunc
+	}{
+		{
+			name:    "无效 ip",
+			ip:      "256.0.0.0",
+			matched: false,
+			errFunc: func(t require.TestingT, err error, i ...interface{}) {
+				var dnsError *net.DNSError
+				if !errors.As(err, &dnsError) {
+					log.Fatal(err)
+				}
+			},
+		},
+		{
+			name:    "非谷歌 ip",
+			ip:      "166.249.90.77",
+			matched: false,
+		},
+		{
+			name:    "谷歌 ip",
+			ip:      "66.249.90.77",
+			matched: true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			m, err := s.CheckCrawler(tc.ip)
+			if err != nil {
+				tc.errFunc(t, err)
+			}
+			require.Equal(t, tc.matched, m)
+		})
+	}
+}