Add support for [RESPONSE_TIME] and >, <, <=, >= operators

README.md

@@ -19,9 +19,10 @@ metrics: true         # Whether to expose metrics at /metrics
 services:
   - name: twinnation  # Name of your service, can be anything
     url: https://twinnation.org/health
-    interval: 15s     # Duration to wait between every status check (opt. default: 10s)
+    interval: 15s     # Duration to wait between every status check (default: 10s)
     conditions:
       - "[STATUS] == 200"
+      - "[RESPONSE_TIME] < 300"
   - name: github
     url: https://api.github.com/healthz
     conditions:
@@ -31,6 +32,19 @@ services:
 Note that you can also add environment variables in the your configuration file (i.e. `$DOMAIN`, `${DOMAIN}`)
 
 
+### Conditions
+
+Here are some examples of conditions you can use:
+
+| Condition                             | Description                               | Values that would pass | Values that would fail |
+| ------------------------------------- | ----------------------------------------- | ---------------------- | ---------------------- |
+| `[STATUS] == 200`                     | Status must be equal to 200               | 200                    | 201, 404, 500          |
+| `[STATUS] < 300`                      | Status must lower than 300                | 200, 201, 299          | 301, 302, 400, 500     |
+| `[STATUS] <= 299`                     | Status must be less than or equal to 299  | 200, 201, 299          | 301, 302, 400, 500     |
+| `[STATUS] > 400`                      | Status must be greater than 400           | 401, 402, 403, 404     | 200, 201, 300, 400     |
+| `[RESPONSE_TIME] < 500`               | Response time must be below 500ms         | 100ms, 200ms, 300ms    | 500ms, 1500ms          |
+
+
 ## Docker
 
 Building the Docker image is done as following:

config.yaml

@@ -2,9 +2,10 @@ metrics: true
 services:
   - name: Twinnation
     url: https://twinnation.org/health
-    interval: 30s
+    interval: 10s
     conditions:
       - "[STATUS] == 200"
+      - "[RESPONSE_TIME] < 20"
   - name: GitHub API
     url: https://api.github.com/healthz
     interval: 30s

core/types.go

@@ -10,6 +10,12 @@ import (
 	"time"
 )
 
+const (
+	StatusPlaceholder       = "[STATUS]"
+	IPPlaceHolder           = "[IP]"
+	ResponseTimePlaceHolder = "[RESPONSE_TIME]"
+)
+
 type HealthStatus struct {
 	Status  string `json:"status"`
 	Message string `json:"message,omitempty"`
@@ -95,44 +101,31 @@ 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)
-		if parts[0] == parts[1] {
-			result.ConditionResults = append(result.ConditionResults, &ConditionResult{
-				Condition:   c,
-				Success:     true,
-				Explanation: fmt.Sprintf("%s is equal to %s", parts[0], parts[1]),
-			})
-			return true
-		} else {
-			result.ConditionResults = append(result.ConditionResults, &ConditionResult{
-				Condition:   c,
-				Success:     false,
-				Explanation: fmt.Sprintf("%s is not equal to %s", parts[0], parts[1]),
-			})
-			return false
-		}
+		success = parts[0] == parts[1]
 	} else if strings.Contains(condition, "!=") {
 		parts := sanitizeAndResolve(strings.Split(condition, "!="), result)
-		if parts[0] != parts[1] {
-			result.ConditionResults = append(result.ConditionResults, &ConditionResult{
-				Condition:   c,
-				Success:     true,
-				Explanation: fmt.Sprintf("%s is not equal to %s", parts[0], parts[1]),
-			})
-			return true
-		} else {
-			result.ConditionResults = append(result.ConditionResults, &ConditionResult{
-				Condition:   c,
-				Success:     false,
-				Explanation: fmt.Sprintf("%s is equal to %s", parts[0], parts[1]),
-			})
-			return false
-		}
+		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 {
@@ -140,13 +133,29 @@ func sanitizeAndResolve(list []string, result *Result) []string {
 	for _, element := range list {
 		element = strings.TrimSpace(element)
 		switch strings.ToUpper(element) {
-		case "[STATUS]":
+		case StatusPlaceholder:
 			element = strconv.Itoa(result.HttpStatus)
-		case "[IP]":
+		case IPPlaceHolder:
 			element = result.Ip
+		case ResponseTimePlaceHolder:
+			element = strconv.Itoa(int(result.Duration.Milliseconds()))
 		default:
 		}
 		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
+}

core/types_test.go

@@ -2,6 +2,7 @@ package core
 
 import (
 	"testing"
+	"time"
 )
 
 func TestEvaluateWithIp(t *testing.T) {
@@ -22,7 +23,7 @@ func TestEvaluateWithStatus(t *testing.T) {
 	}
 }
 
-func TestEvaluateWithFailure(t *testing.T) {
+func TestEvaluateWithStatusFailure(t *testing.T) {
 	condition := Condition("[STATUS] == 200")
 	result := &Result{HttpStatus: 500}
 	condition.evaluate(result)
@@ -31,6 +32,60 @@ func TestEvaluateWithFailure(t *testing.T) {
 	}
 }
 
+func TestEvaluateWithStatusUsingLessThan(t *testing.T) {
+	condition := Condition("[STATUS] < 300")
+	result := &Result{HttpStatus: 201}
+	condition.evaluate(result)
+	if !result.ConditionResults[0].Success {
+		t.Errorf("Condition '%s' should have been a success", condition)
+	}
+}
+
+func TestEvaluateWithStatusFailureUsingLessThan(t *testing.T) {
+	condition := Condition("[STATUS] < 300")
+	result := &Result{HttpStatus: 404}
+	condition.evaluate(result)
+	if result.ConditionResults[0].Success {
+		t.Errorf("Condition '%s' should have been a failure", condition)
+	}
+}
+
+func TestEvaluateWithResponseTimeUsingLessThan(t *testing.T) {
+	condition := Condition("[RESPONSE_TIME] < 500")
+	result := &Result{Duration: time.Millisecond * 50}
+	condition.evaluate(result)
+	if !result.ConditionResults[0].Success {
+		t.Errorf("Condition '%s' should have been a success", condition)
+	}
+}
+
+func TestEvaluateWithResponseTimeUsingGreaterThan(t *testing.T) {
+	condition := Condition("[RESPONSE_TIME] > 500")
+	result := &Result{Duration: time.Millisecond * 750}
+	condition.evaluate(result)
+	if !result.ConditionResults[0].Success {
+		t.Errorf("Condition '%s' should have been a success", condition)
+	}
+}
+
+func TestEvaluateWithResponseTimeUsingGreaterThanOrEqualTo(t *testing.T) {
+	condition := Condition("[RESPONSE_TIME] >= 500")
+	result := &Result{Duration: time.Millisecond * 500}
+	condition.evaluate(result)
+	if !result.ConditionResults[0].Success {
+		t.Errorf("Condition '%s' should have been a success", condition)
+	}
+}
+
+func TestEvaluateWithResponseTimeUsingLessThanOrEqualTo(t *testing.T) {
+	condition := Condition("[RESPONSE_TIME] <= 500")
+	result := &Result{Duration: time.Millisecond * 500}
+	condition.evaluate(result)
+	if !result.ConditionResults[0].Success {
+		t.Errorf("Condition '%s' should have been a success", condition)
+	}
+}
+
 func TestIntegrationEvaluateConditions(t *testing.T) {
 	condition := Condition("[STATUS] == 200")
 	service := Service{