Add regex validator to cloudprober.

PiperOrigin-RevId: 223062931

validators/proto/config.proto

@@ -2,6 +2,7 @@ syntax = "proto2";
 
 import "github.com/google/cloudprober/validators/http/proto/config.proto";
 import "github.com/google/cloudprober/validators/integrity/proto/config.proto";
+import "github.com/google/cloudprober/validators/regex/proto/config.proto";
 
 package cloudprober.validators;
 
@@ -12,5 +13,8 @@ message Validator {
 
     // Data integrity validator
     integrity.Validator integrity_validator = 3;
+
+    // Regex validator
+    regex.Validator regex_validator = 4;
   }
 }

validators/regex/proto/config.proto

@@ -0,0 +1,7 @@
+syntax = "proto2";
+
+package cloudprober.validators.regex;
+
+message Validator {
+  optional string regex = 1;
+}

validators/regex/regex.go

@@ -0,0 +1,61 @@
+// Copyright 2018 Google Inc.
+//
+// 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 regex provides regex validator for the Cloudprober's
+// validator framework.
+package regex
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+
+	"github.com/google/cloudprober/logger"
+	configpb "github.com/google/cloudprober/validators/regex/proto"
+)
+
+// Validator implements a regex validator.
+type Validator struct {
+	r *regexp.Regexp
+	l *logger.Logger
+}
+
+// Init initializes the regex validator.
+// It compiles the regex in the configuration and returns an error if regex
+// doesn't compile for some reason.
+func (v *Validator) Init(config interface{}, l *logger.Logger) error {
+	c, ok := config.(*configpb.Validator)
+	if !ok {
+		return fmt.Errorf("%v is not a valid regex validator config", config)
+	}
+
+	if c.GetRegex() == "" {
+		return errors.New("validator regex string cannot be empty")
+	}
+
+	r, err := regexp.Compile(c.GetRegex())
+	if err != nil {
+		return fmt.Errorf("error compiling the given regex (%s): %v", c.GetRegex(), err)
+	}
+
+	v.r = r
+	v.l = l
+	return nil
+}
+
+// Validate the provided responseBody and return true if responseBody matches
+// the configured regex.
+func (v *Validator) Validate(unusedResponseObj interface{}, responseBody []byte) (bool, error) {
+	return v.r.Match(responseBody), nil
+}

validators/regex/regex_test.go

@@ -0,0 +1,92 @@
+// Copyright 2018 Google Inc.
+//
+// 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 regex
+
+import (
+	"testing"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/google/cloudprober/logger"
+	configpb "github.com/google/cloudprober/validators/regex/proto"
+)
+
+func TestInvalidConfig(t *testing.T) {
+	// Empty config
+	testConfig := &configpb.Validator{}
+	v := Validator{}
+	err := v.Init(testConfig, &logger.Logger{})
+	if err == nil {
+		t.Errorf("v.Init(%v, l): expected error but got nil", testConfig)
+	}
+
+	// Invalid regex as Go regex doesn't support negative lookaheads.
+	testConfig = &configpb.Validator{
+		Regex: proto.String("(?!cloudprober)"),
+	}
+	v = Validator{}
+	err = v.Init(testConfig, &logger.Logger{})
+	if err == nil {
+		t.Errorf("v.Init(%v, l): expected error but got nil", testConfig)
+	}
+}
+
+func verifyValidate(t *testing.T, respBody []byte, regex string, expected bool) {
+	t.Helper()
+	// Test initializing with pattern string.
+	testConfig := &configpb.Validator{
+		Regex: proto.String(regex),
+	}
+
+	v := Validator{}
+	err := v.Init(testConfig, &logger.Logger{})
+	if err != nil {
+		t.Errorf("v.Init(%v, l): got error: %v", testConfig, err)
+	}
+
+	result, err := v.Validate(nil, respBody)
+	if err != nil {
+		t.Errorf("v.Validate(nil, %s): got error: %v", string(respBody), err)
+	}
+
+	if result != expected {
+		if err != nil {
+			t.Errorf("v.Validate(nil, %s): result: %v, expected: %v", string(respBody), result, expected)
+		}
+	}
+}
+
+func TestPatternString(t *testing.T) {
+	rows := []struct {
+		regex    string
+		respBody []byte
+		expected bool
+	}{
+		{
+			regex:    "cloud.*",
+			respBody: []byte("cloudprober"),
+			expected: true,
+		},
+		{
+			regex:    "[Cc]loud.*",
+			respBody: []byte("Cloudprober"),
+			expected: false,
+		},
+	}
+
+	for _, r := range rows {
+		verifyValidate(t, r.respBody, r.regex, r.expected)
+	}
+
+}

validators/validators.go

@@ -23,6 +23,7 @@ import (
 	"github.com/google/cloudprober/validators/http"
 	"github.com/google/cloudprober/validators/integrity"
 	configpb "github.com/google/cloudprober/validators/proto"
+	"github.com/google/cloudprober/validators/regex"
 )
 
 // Validator interface represents a validator.
@@ -60,6 +61,9 @@ func initValidator(validatorConf *configpb.Validator, l *logger.Logger) (validat
 	case *configpb.Validator_IntegrityValidator:
 		validator = &integrity.Validator{}
 		c = validatorConf.GetIntegrityValidator()
+	case *configpb.Validator_RegexValidator:
+		validator = &regex.Validator{}
+		c = validatorConf.GetRegexValidator()
 	default:
 		err = fmt.Errorf("unknown validator type: %v", validatorConf.Type)
 		return