Add support for headers, method, body and json path with arrays

client/client.go

@@ -0,0 +1,19 @@
+package client
+
+import (
+	"net/http"
+	"time"
+)
+
+var (
+	client *http.Client
+)
+
+func GetHttpClient() *http.Client {
+	if client == nil {
+		client = &http.Client{
+			Timeout: time.Second * 10,
+		}
+	}
+	return client
+}

config.yaml

@@ -1,14 +1,21 @@
 metrics: true
 services:
-  - name: Twinnation
-    url: https://twinnation.org/health
+#  - name: twinnation
+#    interval: 10s
+#    url: https://twinnation.org/health
+#    conditions:
+#      - "[STATUS] == 200"
+#      - "[RESPONSE_TIME] < 1000"
+#      - "[BODY].status == UP"
+  - name: twinnation-articles-api
     interval: 10s
+    url: https://twinnation.org/api/v1/articles
     conditions:
       - "[STATUS] == 200"
-      - "[RESPONSE_TIME] < 500"
-      - "[BODY].status == UP"
-  - name: Example
-    url: https://example.org/
-    interval: 30s
-    conditions:
-      - "[STATUS] == 200"
+      - "[BODY].[0].id == 42"
+
+#  - name: example
+#    url: https://example.org/
+#    interval: 30s
+#    conditions:
+#      - "[STATUS] == 200"

config/config.go

@@ -7,7 +7,6 @@ import (
 	"io/ioutil"
 	"log"
 	"os"
-	"time"
 )
 
 type Config struct {
@@ -74,9 +73,7 @@ func parseAndValidateConfigBytes(yamlBytes []byte) (config *Config, err error) {
 	} else {
 		// Set the default values if they aren't set
 		for _, service := range config.Services {
-			if service.Interval == 0 {
-				service.Interval = 10 * time.Second
-			}
+			service.Validate()
 		}
 	}
 	return

core/condition.go

@@ -0,0 +1,51 @@
+package core
+
+import (
+	"fmt"
+	"log"
+	"strings"
+)
+
+type Condition string
+
+func (c *Condition) evaluate(result *Result) bool {
+	condition := string(*c)
+	success := false
+	var resolvedCondition string
+	if strings.Contains(condition, "==") {
+		parts := sanitizeAndResolve(strings.Split(condition, "=="), result)
+		success = parts[0] == parts[1]
+		resolvedCondition = fmt.Sprintf("%v == %v", parts[0], parts[1])
+	} else if strings.Contains(condition, "!=") {
+		parts := sanitizeAndResolve(strings.Split(condition, "!="), result)
+		success = parts[0] != parts[1]
+		resolvedCondition = fmt.Sprintf("%v != %v", parts[0], parts[1])
+	} else if strings.Contains(condition, "<=") {
+		parts := sanitizeAndResolveNumerical(strings.Split(condition, "<="), result)
+		success = parts[0] <= parts[1]
+		resolvedCondition = fmt.Sprintf("%v <= %v", parts[0], parts[1])
+	} else if strings.Contains(condition, ">=") {
+		parts := sanitizeAndResolveNumerical(strings.Split(condition, ">="), result)
+		success = parts[0] >= parts[1]
+		resolvedCondition = fmt.Sprintf("%v >= %v", parts[0], parts[1])
+	} else if strings.Contains(condition, ">") {
+		parts := sanitizeAndResolveNumerical(strings.Split(condition, ">"), result)
+		success = parts[0] > parts[1]
+		resolvedCondition = fmt.Sprintf("%v > %v", parts[0], parts[1])
+	} else if strings.Contains(condition, "<") {
+		parts := sanitizeAndResolveNumerical(strings.Split(condition, "<"), result)
+		success = parts[0] < parts[1]
+		resolvedCondition = fmt.Sprintf("%v < %v", parts[0], parts[1])
+	} else {
+		result.Errors = append(result.Errors, fmt.Sprintf("invalid condition '%s' has been provided", condition))
+		return false
+	}
+	conditionToDisplay := condition
+	// If the condition isn't a success, return the resolved condition
+	if !success {
+		log.Printf("[Condition][evaluate] Condition '%s' did not succeed because '%s' is false", condition, resolvedCondition)
+		conditionToDisplay = resolvedCondition
+	}
+	result.ConditionResults = append(result.ConditionResults, &ConditionResult{Condition: conditionToDisplay, Success: success})
+	return success
+}

core/condition_test.go

@@ -5,7 +5,7 @@ import (
 	"time"
 )
 
-func TestEvaluateWithIp(t *testing.T) {
+func TestCondition_evaluateWithIp(t *testing.T) {
 	condition := Condition("[IP] == 127.0.0.1")
 	result := &Result{Ip: "127.0.0.1"}
 	condition.evaluate(result)
@@ -14,7 +14,7 @@ func TestEvaluateWithIp(t *testing.T) {
 	}
 }
 
-func TestEvaluateWithStatus(t *testing.T) {
+func TestCondition_evaluateWithStatus(t *testing.T) {
 	condition := Condition("[STATUS] == 201")
 	result := &Result{HttpStatus: 201}
 	condition.evaluate(result)
@@ -23,7 +23,7 @@ func TestEvaluateWithStatus(t *testing.T) {
 	}
 }
 
-func TestEvaluateWithStatusFailure(t *testing.T) {
+func TestCondition_evaluateWithStatusFailure(t *testing.T) {
 	condition := Condition("[STATUS] == 200")
 	result := &Result{HttpStatus: 500}
 	condition.evaluate(result)
@@ -32,7 +32,7 @@ func TestEvaluateWithStatusFailure(t *testing.T) {
 	}
 }
 
-func TestEvaluateWithStatusUsingLessThan(t *testing.T) {
+func TestCondition_evaluateWithStatusUsingLessThan(t *testing.T) {
 	condition := Condition("[STATUS] < 300")
 	result := &Result{HttpStatus: 201}
 	condition.evaluate(result)
@@ -41,7 +41,7 @@ func TestEvaluateWithStatusUsingLessThan(t *testing.T) {
 	}
 }
 
-func TestEvaluateWithStatusFailureUsingLessThan(t *testing.T) {
+func TestCondition_evaluateWithStatusFailureUsingLessThan(t *testing.T) {
 	condition := Condition("[STATUS] < 300")
 	result := &Result{HttpStatus: 404}
 	condition.evaluate(result)
@@ -50,7 +50,7 @@ func TestEvaluateWithStatusFailureUsingLessThan(t *testing.T) {
 	}
 }
 
-func TestEvaluateWithResponseTimeUsingLessThan(t *testing.T) {
+func TestCondition_evaluateWithResponseTimeUsingLessThan(t *testing.T) {
 	condition := Condition("[RESPONSE_TIME] < 500")
 	result := &Result{Duration: time.Millisecond * 50}
 	condition.evaluate(result)
@@ -59,7 +59,7 @@ func TestEvaluateWithResponseTimeUsingLessThan(t *testing.T) {
 	}
 }
 
-func TestEvaluateWithResponseTimeUsingGreaterThan(t *testing.T) {
+func TestCondition_evaluateWithResponseTimeUsingGreaterThan(t *testing.T) {
 	condition := Condition("[RESPONSE_TIME] > 500")
 	result := &Result{Duration: time.Millisecond * 750}
 	condition.evaluate(result)
@@ -68,7 +68,7 @@ func TestEvaluateWithResponseTimeUsingGreaterThan(t *testing.T) {
 	}
 }
 
-func TestEvaluateWithResponseTimeUsingGreaterThanOrEqualTo(t *testing.T) {
+func TestCondition_evaluateWithResponseTimeUsingGreaterThanOrEqualTo(t *testing.T) {
 	condition := Condition("[RESPONSE_TIME] >= 500")
 	result := &Result{Duration: time.Millisecond * 500}
 	condition.evaluate(result)
@@ -77,7 +77,7 @@ func TestEvaluateWithResponseTimeUsingGreaterThanOrEqualTo(t *testing.T) {
 	}
 }
 
-func TestEvaluateWithResponseTimeUsingLessThanOrEqualTo(t *testing.T) {
+func TestCondition_evaluateWithResponseTimeUsingLessThanOrEqualTo(t *testing.T) {
 	condition := Condition("[RESPONSE_TIME] <= 500")
 	result := &Result{Duration: time.Millisecond * 500}
 	condition.evaluate(result)
@@ -86,7 +86,7 @@ func TestEvaluateWithResponseTimeUsingLessThanOrEqualTo(t *testing.T) {
 	}
 }
 
-func TestEvaluateWithBody(t *testing.T) {
+func TestCondition_evaluateWithBody(t *testing.T) {
 	condition := Condition("[BODY] == test")
 	result := &Result{Body: []byte("test")}
 	condition.evaluate(result)
@@ -95,7 +95,7 @@ func TestEvaluateWithBody(t *testing.T) {
 	}
 }
 
-func TestEvaluateWithBodyJsonPath(t *testing.T) {
+func TestCondition_evaluateWithBodyJsonPath(t *testing.T) {
 	condition := Condition("[BODY].status == UP")
 	result := &Result{Body: []byte("{\"status\":\"UP\"}")}
 	condition.evaluate(result)
@@ -104,7 +104,7 @@ func TestEvaluateWithBodyJsonPath(t *testing.T) {
 	}
 }
 
-func TestEvaluateWithBodyJsonPathComplex(t *testing.T) {
+func TestCondition_evaluateWithBodyJsonPathComplex(t *testing.T) {
 	condition := Condition("[BODY].data.name == john")
 	result := &Result{Body: []byte("{\"data\": {\"id\": 1, \"name\": \"john\"}}")}
 	condition.evaluate(result)
@@ -113,7 +113,7 @@ func TestEvaluateWithBodyJsonPathComplex(t *testing.T) {
 	}
 }
 
-func TestEvaluateWithBodyJsonPathComplexInt(t *testing.T) {
+func TestCondition_evaluateWithBodyJsonPathLongInt(t *testing.T) {
 	condition := Condition("[BODY].data.id == 1")
 	result := &Result{Body: []byte("{\"data\": {\"id\": 1}}")}
 	condition.evaluate(result)
@@ -122,7 +122,16 @@ func TestEvaluateWithBodyJsonPathComplexInt(t *testing.T) {
 	}
 }
 
-func TestEvaluateWithBodyJsonPathComplexIntUsingGreaterThan(t *testing.T) {
+func TestCondition_evaluateWithBodyJsonPathComplexInt(t *testing.T) {
+	condition := Condition("[BODY].data[1].id == 2")
+	result := &Result{Body: []byte("{\"data\": [{\"id\": 1}, {\"id\": 2}, {\"id\": 3}]}")}
+	condition.evaluate(result)
+	if !result.ConditionResults[0].Success {
+		t.Errorf("Condition '%s' should have been a success", condition)
+	}
+}
+
+func TestCondition_evaluateWithBodyJsonPathComplexIntUsingGreaterThan(t *testing.T) {
 	condition := Condition("[BODY].data.id > 0")
 	result := &Result{Body: []byte("{\"data\": {\"id\": 1}}")}
 	condition.evaluate(result)
@@ -131,7 +140,7 @@ func TestEvaluateWithBodyJsonPathComplexIntUsingGreaterThan(t *testing.T) {
 	}
 }
 
-func TestEvaluateWithBodyJsonPathComplexIntFailureUsingGreaterThan(t *testing.T) {
+func TestCondition_evaluateWithBodyJsonPathComplexIntFailureUsingGreaterThan(t *testing.T) {
 	condition := Condition("[BODY].data.id > 5")
 	result := &Result{Body: []byte("{\"data\": {\"id\": 1}}")}
 	condition.evaluate(result)
@@ -140,7 +149,7 @@ func TestEvaluateWithBodyJsonPathComplexIntFailureUsingGreaterThan(t *testing.T)
 	}
 }
 
-func TestEvaluateWithBodyJsonPathComplexIntUsingLessThan(t *testing.T) {
+func TestCondition_evaluateWithBodyJsonPathComplexIntUsingLessThan(t *testing.T) {
 	condition := Condition("[BODY].data.id < 5")
 	result := &Result{Body: []byte("{\"data\": {\"id\": 2}}")}
 	condition.evaluate(result)
@@ -149,7 +158,7 @@ func TestEvaluateWithBodyJsonPathComplexIntUsingLessThan(t *testing.T) {
 	}
 }
 
-func TestEvaluateWithBodyJsonPathComplexIntFailureUsingLessThan(t *testing.T) {
+func TestCondition_evaluateWithBodyJsonPathComplexIntFailureUsingLessThan(t *testing.T) {
 	condition := Condition("[BODY].data.id < 5")
 	result := &Result{Body: []byte("{\"data\": {\"id\": 10}}")}
 	condition.evaluate(result)
@@ -157,35 +166,3 @@ func TestEvaluateWithBodyJsonPathComplexIntFailureUsingLessThan(t *testing.T) {
 		t.Errorf("Condition '%s' should have been a failure", condition)
 	}
 }
-
-func TestIntegrationEvaluateConditions(t *testing.T) {
-	condition := Condition("[STATUS] == 200")
-	service := Service{
-		Name:       "TwiNNatioN",
-		Url:        "https://twinnation.org/health",
-		Conditions: []*Condition{&condition},
-	}
-	result := service.EvaluateConditions()
-	if !result.ConditionResults[0].Success {
-		t.Errorf("Condition '%s' should have been a success", condition)
-	}
-	if !result.Success {
-		t.Error("Because all conditions passed, this should have been a success")
-	}
-}
-
-func TestIntegrationEvaluateConditionsWithFailure(t *testing.T) {
-	condition := Condition("[STATUS] == 500")
-	service := Service{
-		Name:       "TwiNNatioN",
-		Url:        "https://twinnation.org/health",
-		Conditions: []*Condition{&condition},
-	}
-	result := service.EvaluateConditions()
-	if result.ConditionResults[0].Success {
-		t.Errorf("Condition '%s' should have been a failure", condition)
-	}
-	if result.Success {
-		t.Error("Because one of the conditions failed, success should have been false")
-	}
-}

core/service.go

@@ -0,0 +1,95 @@
+package core
+
+import (
+	"bytes"
+	"github.com/TwinProduction/gatus/client"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/url"
+	"time"
+)
+
+type Service struct {
+	Name       string            `yaml:"name"`
+	Interval   time.Duration     `yaml:"interval,omitempty"`
+	Url        string            `yaml:"url"`
+	Method     string            `yaml:"method,omitempty"`
+	Body       string            `yaml:"body,omitempty"`
+	Headers    map[string]string `yaml:"headers"`
+	Conditions []*Condition      `yaml:"conditions"`
+}
+
+func (service *Service) Validate() {
+	// Set default values
+	if service.Interval == 0 {
+		service.Interval = 10 * time.Second
+	}
+	if len(service.Method) == 0 {
+		service.Method = http.MethodGet
+	}
+
+	// Make sure that the request can be created
+	_, err := http.NewRequest(service.Method, service.Url, bytes.NewBuffer([]byte(service.Body)))
+	if err != nil {
+		panic(err)
+	}
+}
+
+func (service *Service) EvaluateConditions() *Result {
+	result := &Result{Success: true, Errors: []string{}}
+	service.getIp(result)
+	if len(result.Errors) == 0 {
+		service.call(result)
+	} else {
+		result.Success = false
+	}
+	for _, condition := range service.Conditions {
+		success := condition.evaluate(result)
+		if !success {
+			result.Success = false
+		}
+	}
+	result.Timestamp = time.Now()
+	return result
+}
+
+func (service *Service) getIp(result *Result) {
+	urlObject, err := url.Parse(service.Url)
+	if err != nil {
+		result.Errors = append(result.Errors, err.Error())
+		return
+	}
+	result.Hostname = urlObject.Hostname()
+	ips, err := net.LookupIP(urlObject.Hostname())
+	if err != nil {
+		result.Errors = append(result.Errors, err.Error())
+		return
+	}
+	result.Ip = ips[0].String()
+}
+
+func (service *Service) call(result *Result) {
+	request := service.buildRequest()
+	startTime := time.Now()
+	response, err := client.GetHttpClient().Do(request)
+	if err != nil {
+		result.Duration = time.Since(startTime)
+		result.Errors = append(result.Errors, err.Error())
+		return
+	}
+	result.Duration = time.Since(startTime)
+	result.HttpStatus = response.StatusCode
+	result.Body, err = ioutil.ReadAll(response.Body)
+	if err != nil {
+		result.Errors = append(result.Errors, err.Error())
+	}
+}
+
+func (service *Service) buildRequest() *http.Request {
+	request, _ := http.NewRequest(service.Method, service.Url, bytes.NewBuffer([]byte(service.Body)))
+	for k, v := range service.Headers {
+		request.Header.Set(k, v)
+	}
+	return request
+}

core/service_test.go

@@ -0,0 +1,37 @@
+package core
+
+import (
+	"testing"
+)
+
+func TestIntegrationEvaluateConditions(t *testing.T) {
+	condition := Condition("[STATUS] == 200")
+	service := Service{
+		Name:       "TwiNNatioN",
+		Url:        "https://twinnation.org/health",
+		Conditions: []*Condition{&condition},
+	}
+	result := service.EvaluateConditions()
+	if !result.ConditionResults[0].Success {
+		t.Errorf("Condition '%s' should have been a success", condition)
+	}
+	if !result.Success {
+		t.Error("Because all conditions passed, this should have been a success")
+	}
+}
+
+func TestIntegrationEvaluateConditionsWithFailure(t *testing.T) {
+	condition := Condition("[STATUS] == 500")
+	service := Service{
+		Name:       "TwiNNatioN",
+		Url:        "https://twinnation.org/health",
+		Conditions: []*Condition{&condition},
+	}
+	result := service.EvaluateConditions()
+	if result.ConditionResults[0].Success {
+		t.Errorf("Condition '%s' should have been a failure", condition)
+	}
+	if result.Success {
+		t.Error("Because one of the conditions failed, success should have been false")
+	}
+}

core/types.go

@@ -1,24 +1,9 @@
 package core
 
 import (
-	"fmt"
-	"github.com/TwinProduction/gatus/jsonpath"
-	"io/ioutil"
-	"net"
-	"net/http"
-	"net/url"
-	"strconv"
-	"strings"
 	"time"
 )
 
-const (
-	StatusPlaceholder       = "[STATUS]"
-	IPPlaceHolder           = "[IP]"
-	ResponseTimePlaceHolder = "[RESPONSE_TIME]"
-	BodyPlaceHolder         = "[BODY]"
-)
-
 type HealthStatus struct {
 	Status  string `json:"status"`
 	Message string `json:"message,omitempty"`
@@ -36,135 +21,7 @@ type Result struct {
 	Timestamp        time.Time          `json:"timestamp"`
 }
 
-type Service struct {
-	Name       string        `yaml:"name"`
-	Url        string        `yaml:"url"`
-	Interval   time.Duration `yaml:"interval,omitempty"`
-	Conditions []*Condition  `yaml:"conditions"`
-}
-
-func (service *Service) getIp(result *Result) {
-	urlObject, err := url.Parse(service.Url)
-	if err != nil {
-		result.Errors = append(result.Errors, err.Error())
-		return
-	}
-	result.Hostname = urlObject.Hostname()
-	ips, err := net.LookupIP(urlObject.Hostname())
-	if err != nil {
-		result.Errors = append(result.Errors, err.Error())
-		return
-	}
-	result.Ip = ips[0].String()
-}
-
-func (service *Service) call(result *Result) {
-	// TODO: re-use the same client instead of creating multiple clients
-	client := &http.Client{
-		Timeout: time.Second * 10,
-	}
-	startTime := time.Now()
-	response, err := client.Get(service.Url)
-	if err != nil {
-		result.Errors = append(result.Errors, err.Error())
-		return
-	}
-	result.Duration = time.Now().Sub(startTime)
-	result.HttpStatus = response.StatusCode
-	result.Body, err = ioutil.ReadAll(response.Body)
-	if err != nil {
-		result.Errors = append(result.Errors, err.Error())
-	}
-}
-
-func (service *Service) EvaluateConditions() *Result {
-	result := &Result{Success: true, Errors: []string{}}
-	service.getIp(result)
-	if len(result.Errors) == 0 {
-		service.call(result)
-	} else {
-		result.Success = false
-	}
-	for _, condition := range service.Conditions {
-		success := condition.evaluate(result)
-		if !success {
-			result.Success = false
-		}
-	}
-	result.Timestamp = time.Now()
-	return result
-}
-
 type ConditionResult struct {
-	Condition *Condition `json:"condition"`
-	Success   bool       `json:"success"`
-}
-
-type Condition string
-
-func (c *Condition) evaluate(result *Result) bool {
-	condition := string(*c)
-	success := false
-	if strings.Contains(condition, "==") {
-		parts := sanitizeAndResolve(strings.Split(condition, "=="), result)
-		success = parts[0] == parts[1]
-	} else if strings.Contains(condition, "!=") {
-		parts := sanitizeAndResolve(strings.Split(condition, "!="), result)
-		success = parts[0] != parts[1]
-	} else if strings.Contains(condition, "<=") {
-		parts := sanitizeAndResolveNumerical(strings.Split(condition, "<="), result)
-		success = parts[0] <= parts[1]
-	} else if strings.Contains(condition, ">=") {
-		parts := sanitizeAndResolveNumerical(strings.Split(condition, ">="), result)
-		success = parts[0] >= parts[1]
-	} else if strings.Contains(condition, ">") {
-		parts := sanitizeAndResolveNumerical(strings.Split(condition, ">"), result)
-		success = parts[0] > parts[1]
-	} else if strings.Contains(condition, "<") {
-		parts := sanitizeAndResolveNumerical(strings.Split(condition, "<"), result)
-		success = parts[0] < parts[1]
-	} else {
-		result.Errors = append(result.Errors, fmt.Sprintf("invalid condition '%s' has been provided", condition))
-		return false
-	}
-	result.ConditionResults = append(result.ConditionResults, &ConditionResult{Condition: c, Success: success})
-	return success
-}
-
-func sanitizeAndResolve(list []string, result *Result) []string {
-	var sanitizedList []string
-	for _, element := range list {
-		element = strings.TrimSpace(element)
-		switch strings.ToUpper(element) {
-		case StatusPlaceholder:
-			element = strconv.Itoa(result.HttpStatus)
-		case IPPlaceHolder:
-			element = result.Ip
-		case ResponseTimePlaceHolder:
-			element = strconv.Itoa(int(result.Duration.Milliseconds()))
-		case BodyPlaceHolder:
-			element = string(result.Body)
-		default:
-			// if starts with BodyPlaceHolder, then do the jsonpath thingy
-			if strings.HasPrefix(element, BodyPlaceHolder) {
-				element = jsonpath.Eval(strings.Replace(element, fmt.Sprintf("%s.", BodyPlaceHolder), "", 1), result.Body)
-			}
-		}
-		sanitizedList = append(sanitizedList, element)
-	}
-	return sanitizedList
-}
-
-func sanitizeAndResolveNumerical(list []string, result *Result) []int {
-	var sanitizedNumbers []int
-	sanitizedList := sanitizeAndResolve(list, result)
-	for _, element := range sanitizedList {
-		if number, err := strconv.Atoi(element); err != nil {
-			// Default to 0 if the string couldn't be converted to an integer
-			sanitizedNumbers = append(sanitizedNumbers, 0)
-		} else {
-			sanitizedNumbers = append(sanitizedNumbers, number)
-		}
-	}
-	return sanitizedNumbers
+	Condition string `json:"condition"`
+	Success   bool   `json:"success"`
 }

core/util.go

@@ -0,0 +1,61 @@
+package core
+
+import (
+	"fmt"
+	"github.com/TwinProduction/gatus/jsonpath"
+	"strconv"
+	"strings"
+)
+
+const (
+	StatusPlaceholder       = "[STATUS]"
+	IPPlaceHolder           = "[IP]"
+	ResponseTimePlaceHolder = "[RESPONSE_TIME]"
+	BodyPlaceHolder         = "[BODY]"
+
+	InvalidConditionElementSuffix = "(INVALID)"
+)
+
+func sanitizeAndResolve(list []string, result *Result) []string {
+	var sanitizedList []string
+	for _, element := range list {
+		element = strings.TrimSpace(element)
+		switch strings.ToUpper(element) {
+		case StatusPlaceholder:
+			element = strconv.Itoa(result.HttpStatus)
+		case IPPlaceHolder:
+			element = result.Ip
+		case ResponseTimePlaceHolder:
+			element = strconv.Itoa(int(result.Duration.Milliseconds()))
+		case BodyPlaceHolder:
+			element = string(result.Body)
+		default:
+			// if starts with BodyPlaceHolder, then evaluate json path
+			if strings.HasPrefix(element, BodyPlaceHolder) {
+				resolvedElement, err := jsonpath.Eval(strings.Replace(element, fmt.Sprintf("%s.", BodyPlaceHolder), "", 1), result.Body)
+				if err != nil {
+					result.Errors = append(result.Errors, err.Error())
+					element = fmt.Sprintf("%s %s", element, InvalidConditionElementSuffix)
+				} else {
+					element = resolvedElement
+				}
+			}
+		}
+		sanitizedList = append(sanitizedList, element)
+	}
+	return sanitizedList
+}
+
+func sanitizeAndResolveNumerical(list []string, result *Result) []int {
+	var sanitizedNumbers []int
+	sanitizedList := sanitizeAndResolve(list, result)
+	for _, element := range sanitizedList {
+		if number, err := strconv.Atoi(element); err != nil {
+			// Default to 0 if the string couldn't be converted to an integer
+			sanitizedNumbers = append(sanitizedNumbers, 0)
+		} else {
+			sanitizedNumbers = append(sanitizedNumbers, number)
+		}
+	}
+	return sanitizedNumbers
+}

jsonpath/jsonpath.go

@@ -3,28 +3,69 @@ package jsonpath
 import (
 	"encoding/json"
 	"fmt"
+	"strconv"
 	"strings"
 )
 
-func Eval(path string, b []byte) string {
-	var object map[string]interface{}
+func Eval(path string, b []byte) (string, error) {
+	var object interface{}
 	err := json.Unmarshal(b, &object)
 	if err != nil {
-		return ""
+		// Try to unmarshall it into an array instead
+		return "", err
 	}
 	return walk(path, object)
 }
 
-func walk(path string, object map[string]interface{}) string {
+func walk(path string, object interface{}) (string, error) {
 	keys := strings.Split(path, ".")
-	targetKey := keys[0]
-	// if there's only one key and the target key is that key, then return its value
-	if len(keys) == 1 {
-		return fmt.Sprintf("%v", object[targetKey])
-	}
+	currentKey := keys[0]
 	// if there's more than one key, then walk deeper
-	if len(keys) > 0 {
-		return walk(strings.Replace(path, fmt.Sprintf("%s.", targetKey), "", 1), object[targetKey].(map[string]interface{}))
+	if len(keys) > 1 {
+		switch value := extractValue(currentKey, object).(type) {
+		case map[string]interface{}:
+			return walk(strings.Replace(path, fmt.Sprintf("%s.", currentKey), "", 1), value)
+		case interface{}:
+			return fmt.Sprintf("%v", value), nil
+		default:
+			return "", fmt.Errorf("couldn't walk through '%s' because type was '%T', but expected 'map[string]interface{}'", currentKey, value)
+		}
 	}
-	return ""
+	// if there's only one key and the target key is that key, then return its value
+	return fmt.Sprintf("%v", extractValue(currentKey, object)), nil
+}
+
+func extractValue(currentKey string, value interface{}) interface{} {
+	// Check if the current key ends with [#]
+	if strings.HasSuffix(currentKey, "]") && strings.Contains(currentKey, "[") {
+		tmp := strings.SplitN(currentKey, "[", 3)
+		arrayIndex, err := strconv.Atoi(strings.Replace(tmp[1], "]", "", 1))
+		if err != nil {
+			return value
+		}
+		currentKey := tmp[0]
+		// if currentKey contains only an index (i.e. [0] or 0)
+		if len(currentKey) == 0 {
+			array := value.([]interface{})
+			if len(array) > arrayIndex {
+				if len(tmp) > 2 {
+					// Nested array? Go deeper.
+					return extractValue(fmt.Sprintf("%s[%s", currentKey, tmp[2]), array[arrayIndex])
+				}
+				return array[arrayIndex]
+			}
+			return nil
+		}
+		// if currentKey contains both a key and an index (i.e. data[0])
+		array := value.(map[string]interface{})[currentKey].([]interface{})
+		if len(array) > arrayIndex {
+			if len(tmp) > 2 {
+				// Nested array? Go deeper.
+				return extractValue(fmt.Sprintf("[%s", tmp[2]), array[arrayIndex])
+			}
+			return array[arrayIndex]
+		}
+		return nil
+	}
+	return value.(map[string]interface{})[currentKey]
 }

jsonpath/jsonpath_test.go

@@ -0,0 +1,148 @@
+package jsonpath
+
+import "testing"
+
+func TestEval(t *testing.T) {
+	path := "simple"
+	data := `{"simple": "value"}`
+
+	expectedOutput := "value"
+
+	output, err := Eval(path, []byte(data))
+	if err != nil {
+		t.Error("Didn't expect any error, but got", err)
+	}
+	if output != expectedOutput {
+		t.Errorf("Expected output to be %v, but was %v", expectedOutput, output)
+	}
+}
+
+func TestEvalWithLongSimpleWalk(t *testing.T) {
+	path := "long.simple.walk"
+	data := `{"long": {"simple": {"walk": "value"}}}`
+
+	expectedOutput := "value"
+
+	output, err := Eval(path, []byte(data))
+	if err != nil {
+		t.Error("Didn't expect any error, but got", err)
+	}
+	if output != expectedOutput {
+		t.Errorf("Expected output to be %v, but was %v", expectedOutput, output)
+	}
+}
+
+func TestEvalWithArrayOfMaps(t *testing.T) {
+	path := "ids[1].id"
+	data := `{"ids": [{"id": 1}, {"id": 2}]}`
+
+	expectedOutput := "2"
+
+	output, err := Eval(path, []byte(data))
+	if err != nil {
+		t.Error("Didn't expect any error, but got", err)
+	}
+	if output != expectedOutput {
+		t.Errorf("Expected output to be %v, but was %v", expectedOutput, output)
+	}
+}
+
+func TestEvalWithArrayOfValues(t *testing.T) {
+	path := "ids[0]"
+	data := `{"ids": [1, 2]}`
+
+	expectedOutput := "1"
+
+	output, err := Eval(path, []byte(data))
+	if err != nil {
+		t.Error("Didn't expect any error, but got", err)
+	}
+	if output != expectedOutput {
+		t.Errorf("Expected output to be %v, but was %v", expectedOutput, output)
+	}
+}
+
+func TestEvalWithRootArrayOfValues(t *testing.T) {
+	path := "[1]"
+	data := `[1, 2]`
+
+	expectedOutput := "2"
+
+	output, err := Eval(path, []byte(data))
+	if err != nil {
+		t.Error("Didn't expect any error, but got", err)
+	}
+	if output != expectedOutput {
+		t.Errorf("Expected output to be %v, but was %v", expectedOutput, output)
+	}
+}
+
+func TestEvalWithRootArrayOfMaps(t *testing.T) {
+	path := "[0].id"
+	data := `[{"id": 1}, {"id": 2}]`
+
+	expectedOutput := "1"
+
+	output, err := Eval(path, []byte(data))
+	if err != nil {
+		t.Error("Didn't expect any error, but got", err)
+	}
+	if output != expectedOutput {
+		t.Errorf("Expected output to be %v, but was %v", expectedOutput, output)
+	}
+}
+
+func TestEvalWithRootArrayOfMapsUsingInvalidArrayIndex(t *testing.T) {
+	path := "[5].id"
+	data := `[{"id": 1}, {"id": 2}]`
+
+	_, err := Eval(path, []byte(data))
+	if err == nil {
+		t.Error("Should've returned an error, but didn't")
+	}
+}
+
+func TestEvalWithLongWalkAndArray(t *testing.T) {
+	path := "data.ids[0].id"
+	data := `{"data": {"ids": [{"id": 1}, {"id": 2}, {"id": 3}]}}`
+
+	expectedOutput := "1"
+
+	output, err := Eval(path, []byte(data))
+	if err != nil {
+		t.Error("Didn't expect any error, but got", err)
+	}
+	if output != expectedOutput {
+		t.Errorf("Expected output to be %v, but was %v", expectedOutput, output)
+	}
+}
+
+func TestEvalWithNestedArray(t *testing.T) {
+	path := "[3][2]"
+	data := `[[1, 2], [3, 4], [], [5, 6, 7]]`
+
+	expectedOutput := "7"
+
+	output, err := Eval(path, []byte(data))
+	if err != nil {
+		t.Error("Didn't expect any error, but got", err)
+	}
+	if output != expectedOutput {
+		t.Errorf("Expected output to be %v, but was %v", expectedOutput, output)
+	}
+}
+
+func TestEvalWithMapOfNestedArray(t *testing.T) {
+	path := "data[1][1]"
+	data := `{"data": [["a", "b", "c"], ["d", "e", "f"]]}`
+
+	expectedOutput := "e"
+
+	output, err := Eval(path, []byte(data))
+	if err != nil {
+		t.Error("Didn't expect any error, but got", err)
+	}
+	if output != expectedOutput {
+		t.Errorf("Expected output to be %v, but was %v", expectedOutput, output)
+	}
+}

main.go

@@ -3,7 +3,6 @@ package main
 import (
 	"encoding/json"
 	"github.com/TwinProduction/gatus/config"
-	"github.com/TwinProduction/gatus/core"
 	"github.com/TwinProduction/gatus/watchdog"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"log"
@@ -13,7 +12,6 @@ import (
 
 func main() {
 	cfg := loadConfiguration()
-	go watchdog.Monitor(cfg)
 	http.HandleFunc("/api/v1/results", serviceResultsHandler)
 	http.HandleFunc("/health", healthHandler)
 	http.Handle("/", http.FileServer(http.Dir("./static")))
@@ -21,6 +19,7 @@ func main() {
 		http.Handle("/metrics", promhttp.Handler())
 	}
 	log.Println("[main][main] Listening on port 8080")
+	go watchdog.Monitor(cfg)
 	log.Fatal(http.ListenAndServe(":8080", nil))
 }
 
@@ -40,21 +39,20 @@ func loadConfiguration() *config.Config {
 
 func serviceResultsHandler(writer http.ResponseWriter, _ *http.Request) {
 	serviceResults := watchdog.GetServiceResults()
+	data, err := json.Marshal(serviceResults)
+	if err != nil {
+		log.Printf("[main][serviceResultsHandler] Unable to marshall object to JSON: %s", err.Error())
+		writer.WriteHeader(http.StatusInternalServerError)
+		_, _ = writer.Write([]byte("Unable to marshall object to JSON"))
+		return
+	}
 	writer.Header().Add("Content-type", "application/json")
 	writer.WriteHeader(http.StatusOK)
-	_, _ = writer.Write(structToJsonBytes(serviceResults))
+	_, _ = writer.Write(data)
 }
 
 func healthHandler(writer http.ResponseWriter, _ *http.Request) {
 	writer.Header().Add("Content-type", "application/json")
 	writer.WriteHeader(http.StatusOK)
-	_, _ = writer.Write(structToJsonBytes(&core.HealthStatus{Status: "UP"}))
-}
-
-func structToJsonBytes(obj interface{}) []byte {
-	bytes, err := json.Marshal(obj)
-	if err != nil {
-		log.Printf("[main][structToJsonBytes] Unable to marshall object to JSON: %s", err.Error())
-	}
-	return bytes
+	_, _ = writer.Write([]byte("{\"status\":\"UP\"}"))
 }

static/index.html

@@ -49,13 +49,13 @@
 			let conditions = "";
 			for (let conditionResultIndex in serviceResult['condition-results']) {
 				let conditionResult = serviceResult['condition-results'][conditionResultIndex];
-				conditions += "\n- " + (conditionResult.success ? "✓" : "X") + " ~ " + conditionResult.condition;
+				conditions += "\n" + (conditionResult.success ? "✓" : "X") + " ~ " + htmlEntities(conditionResult.condition);
 			}
 			output = output.replace("__CONDITIONS__", "\n\nConditions:" + conditions);
 			if (serviceResult['errors'].length > 0) {
 				let errors = "";
 				for (let errorIndex in serviceResult['errors']) {
-					errors += "\n- " + serviceResult['errors'][errorIndex];
+					errors += "\n- " + htmlEntities(serviceResult['errors'][errorIndex]);
 				}
 				output = output.replace("__ERRORS__", "\n\nErrors: " + errors);
 			} else {
@@ -116,6 +116,15 @@
 			return YYYY+"-"+MM+"-"+DD+" "+hh+":"+mm+":"+ss;
 		}
 
+		function htmlEntities(s) {
+			return String(s)
+				.replace(/&/g, '&')
+				.replace(/</g, '&lt;')
+				.replace(/>/g, '&gt;')
+				.replace(/"/g, '&quot;')
+				.replace(/'/g, '&apos;');
+		}
+
 		refreshResults();
 		setInterval(function() {
 			refreshResults();

watchdog/watchdog.go

@@ -22,7 +22,7 @@ func Monitor(cfg *config.Config) {
 	for _, service := range cfg.Services {
 		go monitor(service)
 		// To prevent multiple requests from running at the same time
-		time.Sleep(500 * time.Millisecond)
+		time.Sleep(1111 * time.Millisecond)
 	}
 }