Add dns feature

checker/dns/a/a.go

@@ -0,0 +1,102 @@
+// Copyright 2023 The Wait4X Authors
+//
+// 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 a
+
+import (
+	"context"
+	"fmt"
+	"net"
+
+	"wait4x.dev/v2/checker"
+)
+
+// Option configures an DNS A records
+type Option func(d *A)
+
+// A represents DNS A data structure
+type A struct {
+	nameserver  string
+	address     string
+	expectedIPs []string
+	resolver    *net.Resolver
+}
+
+// New creates the DNS A checker
+func New(address string, opts ...Option) checker.Checker {
+	d := &A{
+		address: address,
+	}
+
+	// apply the list of options to A
+	for _, opt := range opts {
+		opt(d)
+	}
+
+	// Nameserver settings.
+	d.resolver = net.DefaultResolver
+	if d.nameserver != "" {
+		d.resolver = &net.Resolver{
+			Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
+				dialer := net.Dialer{}
+				return dialer.DialContext(ctx, network, d.nameserver)
+			},
+		}
+	}
+
+	return d
+}
+
+// WithNameServer overrides the default nameserver
+func WithNameServer(nameserver string) Option {
+	return func(d *A) {
+		d.nameserver = nameserver
+	}
+}
+
+// WithExpectedIPV4s sets expected IPv4s
+func WithExpectedIPV4s(ips []string) Option {
+	return func(d *A) {
+		d.expectedIPs = ips
+	}
+}
+
+// Identity returns the identity of the checker
+func (d *A) Identity() (string, error) {
+	return fmt.Sprintf("A %s %s", d.address, d.expectedIPs), nil
+}
+
+// Check checks A DNS records
+func (d *A) Check(ctx context.Context) (err error) {
+	ips, err := d.resolver.LookupIP(ctx, "ip4", d.address)
+	if err != nil {
+		return err
+	}
+
+	for _, ip := range ips {
+		if len(d.expectedIPs) == 0 {
+			return nil
+		}
+		for _, expectedIP := range d.expectedIPs {
+			if expectedIP == ip.String() {
+				return nil
+			}
+		}
+	}
+
+	return checker.NewExpectedError(
+		"the A record value doesn't expect", nil,
+		"actual", ips, "expect", d.expectedIPs,
+	)
+}

checker/dns/a/a_test.go

@@ -0,0 +1,32 @@
+package a
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"wait4x.dev/v2/checker"
+)
+
+const server = "wait4x.dev"
+
+func TestCheckExistenceA(t *testing.T) {
+	d := New(server)
+	assert.Nil(t, d.Check(context.Background()))
+}
+
+func TestCorrectA(t *testing.T) {
+	d := New(server, WithExpectedIPV4s([]string{"172.67.154.180", "127.0.0.1"}))
+	assert.Nil(t, d.Check(context.Background()))
+}
+
+func TestIncorrectA(t *testing.T) {
+	var expectedError *checker.ExpectedError
+	d := New(server, WithExpectedIPV4s([]string{"127.0.0.1"}))
+	assert.ErrorAs(t, d.Check(context.Background()), &expectedError)
+}
+
+func TestCustomNSCorrectA(t *testing.T) {
+	d := New(server, WithExpectedIPV4s([]string{"172.67.154.180"}))
+	assert.Nil(t, d.Check(context.Background()))
+}

checker/dns/aaaa/aaaa.go

@@ -0,0 +1,102 @@
+// Copyright 2023 The Wait4X Authors
+//
+// 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 aaaa
+
+import (
+	"context"
+	"fmt"
+	"net"
+
+	"wait4x.dev/v2/checker"
+)
+
+// Option configures an DNS AAAA records
+type Option func(d *AAAA)
+
+// AAAA represents DNS AAAA data structure
+type AAAA struct {
+	nameserver  string
+	address     string
+	expectedIPs []string
+	resolver    *net.Resolver
+}
+
+// New creates the DNS AAAA checker
+func New(address string, opts ...Option) checker.Checker {
+	d := &AAAA{
+		address: address,
+	}
+
+	// apply the list of options to AAAA
+	for _, opt := range opts {
+		opt(d)
+	}
+
+	// Nameserver settings.
+	d.resolver = net.DefaultResolver
+	if d.nameserver != "" {
+		d.resolver = &net.Resolver{
+			Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
+				dialer := net.Dialer{}
+				return dialer.DialContext(ctx, network, d.nameserver)
+			},
+		}
+	}
+
+	return d
+}
+
+// WithNameServer overrides the default nameserver
+func WithNameServer(nameserver string) Option {
+	return func(d *AAAA) {
+		d.nameserver = nameserver
+	}
+}
+
+// WithExpectedIPV6s sets expected IPv6s
+func WithExpectedIPV6s(ips []string) Option {
+	return func(d *AAAA) {
+		d.expectedIPs = ips
+	}
+}
+
+// Identity returns the identity of the checker
+func (d *AAAA) Identity() (string, error) {
+	return fmt.Sprintf("AAAA %s %s", d.address, d.expectedIPs), nil
+}
+
+// Check checks DNS records
+func (d *AAAA) Check(ctx context.Context) (err error) {
+	values, err := d.resolver.LookupIP(ctx, "ip6", d.address)
+	if err != nil {
+		return err
+	}
+
+	for _, ip := range values {
+		if len(d.expectedIPs) == 0 {
+			return nil
+		}
+		for _, expectedIP := range d.expectedIPs {
+			if expectedIP == ip.String() {
+				return nil
+			}
+		}
+	}
+
+	return checker.NewExpectedError(
+		"the AAAA record value doesn't expect", nil,
+		"actual", values, "expect", d.expectedIPs,
+	)
+}

checker/dns/aaaa/aaaa_test.go

@@ -0,0 +1,32 @@
+package aaaa
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"wait4x.dev/v2/checker"
+)
+
+const server = "wait4x.dev"
+
+func TestCheckExistenceAAAA(t *testing.T) {
+	d := New(server)
+	assert.Nil(t, d.Check(context.Background()))
+}
+
+func TestCorrectAAAA(t *testing.T) {
+	d := New(server, WithExpectedIPV6s([]string{"2606:4700:3034::6815:591"}))
+	assert.Nil(t, d.Check(context.Background()))
+}
+
+func TestIncorrectAAAA(t *testing.T) {
+	var expectedError *checker.ExpectedError
+	d := New(server, WithExpectedIPV6s([]string{"127.0.0.1"}))
+	assert.ErrorAs(t, d.Check(context.Background()), &expectedError)
+}
+
+func TestCustomNSCorrectAAAA(t *testing.T) {
+	d := New(server, WithExpectedIPV6s([]string{"2606:4700:3034::6815:591"}))
+	assert.Nil(t, d.Check(context.Background()))
+}

checker/dns/cname/cname.go

@@ -0,0 +1,102 @@
+// Copyright 2023 The Wait4X Authors
+//
+// 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 cname
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"regexp"
+
+	"wait4x.dev/v2/checker"
+)
+
+// Option configures an DNS CNAME record
+type Option func(d *CNAME)
+
+// CNAME represents DNS CNAME data structure
+type CNAME struct {
+	nameserver      string
+	address         string
+	expectedDomains []string
+	resolver        *net.Resolver
+}
+
+// New creates the DNS CNAME checker
+func New(address string, opts ...Option) checker.Checker {
+	d := &CNAME{
+		address: address,
+	}
+
+	// apply the list of options to CNAME
+	for _, opt := range opts {
+		opt(d)
+	}
+
+	// Nameserver settings.
+	d.resolver = net.DefaultResolver
+	if d.nameserver != "" {
+		d.resolver = &net.Resolver{
+			Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
+				dialer := net.Dialer{}
+				return dialer.DialContext(ctx, network, d.nameserver)
+			},
+		}
+	}
+
+	return d
+}
+
+// WithNameServer overrides the default nameserver
+func WithNameServer(nameserver string) Option {
+	return func(d *CNAME) {
+		d.nameserver = nameserver
+	}
+}
+
+// WithExpectedDomains sets expected domains
+func WithExpectedDomains(doamins []string) Option {
+	return func(d *CNAME) {
+		d.expectedDomains = doamins
+	}
+}
+
+// Identity returns the identity of the checker
+func (d *CNAME) Identity() (string, error) {
+	return fmt.Sprintf("CNAME %s %s", d.address, d.expectedDomains), nil
+}
+
+// Check checks DNS TXT records
+func (d *CNAME) Check(ctx context.Context) (err error) {
+	value, err := d.resolver.LookupCNAME(ctx, d.address)
+	if err != nil {
+		return err
+	}
+
+	if len(value) != 0 && len(d.expectedDomains) == 0 {
+		return nil
+	}
+	for _, expectedDomain := range d.expectedDomains {
+		matched, _ := regexp.MatchString(expectedDomain, value)
+		if matched {
+			return nil
+		}
+	}
+
+	return checker.NewExpectedError(
+		"the CNAME record value doesn't expect", nil,
+		"actual", value, "expect", d.expectedDomains,
+	)
+}