Merge pull request #32 from thomasjpfan/compound_alerts

Adds compound alerts

Author: vfarcic

docs/usage.md

@@ -62,6 +62,12 @@ Please visit [Alerting Overview](https://prometheus.io/docs/alerting/overview/)
 !!! note
     I hope that the number of shortcuts will grow with time thanks to community contributions. Please create [an issue](https://github.com/vfarcic/docker-flow-monitor/issues) with the `alertIf` statement and the suggested shortcut and I'll add it to the code as soon as possible.
 
+### AlertIf Logical Operators
+
+The logical operators `and`, `unless`, and `or` can be used in combinations with AlertIf Parameter Shortcuts. For example, to create an alert that triggers when response time is low unless response time is high, set `alertIf=@resp_time_below:0.025,5m,0.75_unless_@resp_time_above:0.1,5m,0.99`. This alert prevents `@resp_time_below` from triggering while `@resp_time_above` is triggering. The `summary` annotation for this alert will be merged with the `and` operator: "Response time of the service my-service is below 0.025 unless Response time of the service my-service is above 0.1". When using logical operators, there are no default alert labels. The alert labels will have to be manually set by using the `alertLabels` query parameter.
+
+ More information on the logical operators can be found on Prometheus's querying [documentation](https://prometheus.io/docs/prometheus/latest/querying/operators/#logical-set-binary-operators).
+
 ## Remove
 
 !!! tip

server/server.go

@@ -324,40 +324,136 @@ var alertIfShortcutData = map[string]alertIfShortcut{
 
 func (s *serve) formatAlert(alert *prometheus.Alert) {
 	alert.AlertNameFormatted = s.getNameFormatted(fmt.Sprintf("%s_%s", alert.ServiceName, alert.AlertName))
-	if strings.HasPrefix(alert.AlertIf, "@") {
+	if !strings.HasPrefix(alert.AlertIf, "@") {
+		return
+	}
+
+	_, bOp, _ := splitCompoundOp(alert.AlertIf)
+	if len(bOp) > 0 {
+		formatCompoundAlert(alert)
+	} else {
+		formatSingleAlert(alert)
+	}
+
+}
+
+func formatSingleAlert(alert *prometheus.Alert) {
+
+	value := ""
+	alertSplit := strings.Split(alert.AlertIf, ":")
+	shortcut := alertSplit[0]
+
+	if len(alertSplit) > 1 {
+		value = alertSplit[1]
+	}
+
+	data, ok := alertIfShortcutData[shortcut]
+	if !ok {
+		return
+	}
+
+	alert.AlertIf = replaceTags(data.expanded, alert, value)
+
+	if alert.AlertAnnotations == nil {
+		alert.AlertAnnotations = map[string]string{}
+	}
+	for k, v := range data.annotations {
+		if _, ok := alert.AlertAnnotations[k]; !ok {
+			alert.AlertAnnotations[k] = replaceTags(v, alert, value)
+		}
+	}
+
+	if alert.AlertLabels == nil {
+		alert.AlertLabels = map[string]string{}
+	}
+	for k, v := range data.labels {
+		if _, ok := alert.AlertLabels[k]; !ok {
+			alert.AlertLabels[k] = replaceTags(v, alert, value)
+		}
+	}
+}
+
+func formatCompoundAlert(alert *prometheus.Alert) {
+	alertIfStr := alert.AlertIf
+	alertAnnotations := map[string]string{}
+	immutableAnnotations := map[string]struct{}{}
+
+	// copy alert annotations and alert labels
+	if alert.AlertAnnotations != nil {
+		for k := range alert.AlertAnnotations {
+			immutableAnnotations[k] = struct{}{}
+		}
+	}
+
+	var alertIfFormattedBuffer bytes.Buffer
+
+	currentAlert, bOp, alertIfStr := splitCompoundOp(alertIfStr)
+
+	for len(currentAlert) > 0 {
 		value := ""
-		alertSplit := strings.Split(alert.AlertIf, ":")
+		alertSplit := strings.Split(currentAlert, ":")
 		shortcut := alertSplit[0]
 
 		if len(alertSplit) > 1 {
 			value = alertSplit[1]
 		}
-
 		data, ok := alertIfShortcutData[shortcut]
 		if !ok {
 			return
 		}
 
-		alert.AlertIf = replaceTags(data.expanded, alert, value)
-
-		if alert.AlertAnnotations == nil {
-			alert.AlertAnnotations = map[string]string{}
+		alertIfFormattedBuffer.WriteString(replaceTags(data.expanded, alert, value))
+		if len(bOp) > 0 {
+			alertIfFormattedBuffer.WriteString(fmt.Sprintf(" %s ", bOp))
 		}
+
 		for k, v := range data.annotations {
-			if _, ok := alert.AlertAnnotations[k]; !ok {
-				alert.AlertAnnotations[k] = replaceTags(v, alert, value)
+			if _, ok := immutableAnnotations[k]; ok {
+				continue
+			}
+			alertAnnotations[k] += replaceTags(v, alert, value)
+			if len(bOp) > 0 {
+				alertAnnotations[k] += fmt.Sprintf(" %s ", bOp)
 			}
 		}
+		currentAlert, bOp, alertIfStr = splitCompoundOp(alertIfStr)
+	}
 
-		if alert.AlertLabels == nil {
-			alert.AlertLabels = map[string]string{}
+	alert.AlertIf = alertIfFormattedBuffer.String()
+
+	if alert.AlertAnnotations == nil {
+		alert.AlertAnnotations = map[string]string{}
+	}
+
+	for k, v := range alertAnnotations {
+		if _, ok := immutableAnnotations[k]; ok {
+			continue
 		}
-		for k, v := range data.labels {
-			if _, ok := alert.AlertLabels[k]; !ok {
-				alert.AlertLabels[k] = replaceTags(v, alert, value)
-			}
+		alert.AlertAnnotations[k] = v
+	}
+
+}
+
+// splitCompoundOp find splits string into three pieces if it includes _unless_,
+// _and_, or _or_. For example, hello_and_world_or_earth will return [hello, and, world_or_earth]
+func splitCompoundOp(s string) (string, string, string) {
+	binaryOps := []string{"unless", "and", "or"}
+
+	minIdx := len(s)
+	minOp := ""
+	for _, bOp := range binaryOps {
+		idx := strings.Index(s, fmt.Sprintf("_%s_", bOp))
+		if idx != -1 && idx < minIdx {
+			minIdx = idx
+			minOp = bOp
 		}
 	}
+
+	if len(minOp) > 0 {
+		return s[:minIdx], minOp, s[minIdx+len(minOp)+2:]
+	}
+	return s, "", ""
+
 }
 
 func replaceTags(tag string, alert *prometheus.Alert, value string) string {

server/server_test.go

@@ -7,6 +7,7 @@ import (
 	"net/http/httptest"
 	"net/url"
 	"os"
+	"strings"
 	"testing"
 	"time"
 
@@ -310,6 +311,119 @@ func (s *ServerTestSuite) Test_ReconfigureHandler_ExpandsShortcuts() {
 	}
 }
 
+func (s *ServerTestSuite) Test_ReconfigureHandler_ExpandsShortcuts_CompoundOps() {
+	testData := []struct {
+		expected    string
+		shortcut    string
+		annotations map[string]string
+		labels      map[string]string
+	}{
+		{
+			`sum(rate(http_server_resp_time_bucket{job="my-service", le="0.025"}[5m])) / sum(rate(http_server_resp_time_count{job="my-service"}[5m])) > 0.75 unless sum(rate(http_server_resp_time_bucket{job="my-service", le="0.1"}[5m])) / sum(rate(http_server_resp_time_count{job="my-service"}[5m])) < 0.99`,
+			`@resp_time_below:0.025,5m,0.75_unless_@resp_time_above:0.1,5m,0.99`,
+			map[string]string{"summary": "Response time of the service my-service is below 0.025 unless Response time of the service my-service is above 0.1"},
+			map[string]string{},
+		},
+		{
+			`sum(rate(http_server_resp_time_bucket{job="my-service", le="0.025"}[5m])) / sum(rate(http_server_resp_time_count{job="my-service"}[5m])) > 0.75 unless sum(rate(http_server_resp_time_bucket{job="my-service", le="0.1"}[5m])) / sum(rate(http_server_resp_time_count{job="my-service"}[5m])) < 0.99`,
+			`@resp_time_below:0.025,5m,0.75_unless_@resp_time_above:0.1,5m,0.99`,
+			map[string]string{"summary": "Response time of the service my-service is below 0.025 unless Response time of the service my-service is above 0.1"},
+			map[string]string{"receiver": "system", "service": "my-service", "type": "service"},
+		},
+		{
+			`sum(rate(http_server_resp_time_bucket{job="my-service", le="0.1"}[5m])) / sum(rate(http_server_resp_time_count{job="my-service"}[5m])) < 0.99 and container_memory_usage_bytes{container_label_com_docker_swarm_service_name="my-service"}/container_spec_memory_limit_bytes{container_label_com_docker_swarm_service_name="my-service"} > 0.8`,
+			`@resp_time_above:0.1,5m,0.99_and_@service_mem_limit:0.8`,
+			map[string]string{"summary": "Response time of the service my-service is above 0.1 and Memory of the service my-service is over 0.8"},
+			map[string]string{"receiver": "system", "service": "my-service"},
+		},
+		{
+			`sum(rate(http_server_resp_time_bucket{job="my-service", le="0.1"}[5m])) / sum(rate(http_server_resp_time_count{job="my-service"}[5m])) < 0.99 or container_memory_usage_bytes{container_label_com_docker_swarm_service_name="my-service"}/container_spec_memory_limit_bytes{container_label_com_docker_swarm_service_name="my-service"} > 0.8`,
+			`@resp_time_above:0.1,5m,0.99_or_@service_mem_limit:0.8`,
+			map[string]string{"summary": "Response time of the service my-service is above 0.1 or Memory of the service my-service is over 0.8"},
+			map[string]string{"receiver": "system"},
+		},
+		{
+			`container_memory_usage_bytes{container_label_com_docker_swarm_service_name="my-service"}/container_spec_memory_limit_bytes{container_label_com_docker_swarm_service_name="my-service"} > 0.8 and sum(rate(http_server_resp_time_bucket{job="my-service", le="0.025"}[5m])) / sum(rate(http_server_resp_time_count{job="my-service"}[5m])) > 0.75 unless sum(rate(http_server_resp_time_bucket{job="my-service", le="0.1"}[5m])) / sum(rate(http_server_resp_time_count{job="my-service"}[5m])) < 0.99`,
+			`@service_mem_limit:0.8_and_@resp_time_below:0.025,5m,0.75_unless_@resp_time_above:0.1,5m,0.99`,
+			map[string]string{"summary": "Memory of the service my-service is over 0.8 and Response time of the service my-service is below 0.025 unless Response time of the service my-service is above 0.1"},
+			map[string]string{"receiver": "system"},
+		},
+	}
+
+	for _, data := range testData {
+		expected := prometheus.Alert{
+			AlertAnnotations:   data.annotations,
+			AlertFor:           "my-for",
+			AlertIf:            data.expected,
+			AlertLabels:        data.labels,
+			AlertName:          "my-alert",
+			AlertNameFormatted: "myservice_myalert",
+			ServiceName:        "my-service",
+			Replicas:           3,
+		}
+		rwMock := ResponseWriterMock{}
+		alertQueries := []string{}
+		for k, v := range data.labels {
+			alertQueries = append(alertQueries, fmt.Sprintf("%s=%s", k, v))
+		}
+		alertQueryStr := strings.Join(alertQueries, ",")
+		addr := fmt.Sprintf(
+			"/v1/docker-flow-monitor?serviceName=%s&alertName=%s&alertIf=%s&alertFor=%s&replicas=3",
+			expected.ServiceName,
+			expected.AlertName,
+			data.shortcut,
+			expected.AlertFor,
+		)
+		if len(alertQueries) > 0 {
+			addr += fmt.Sprintf("&alertLabels=%s", alertQueryStr)
+		}
+		req, _ := http.NewRequest("GET", addr, nil)
+
+		serve := New()
+		serve.ReconfigureHandler(rwMock, req)
+
+		s.Equal(expected, serve.alerts[expected.AlertNameFormatted])
+	}
+}
+
+func (s *ServerTestSuite) Test_ReconfigureHandler_DoesNotExpandAnnotations_WhenTheyAreAlreadySet_CompoundOps() {
+	testData := struct {
+		expected    string
+		shortcut    string
+		annotations map[string]string
+		labels      map[string]string
+	}{
+		`sum(rate(http_server_resp_time_bucket{job="my-service", le="0.025"}[5m])) / sum(rate(http_server_resp_time_count{job="my-service"}[5m])) > 0.75 unless sum(rate(http_server_resp_time_bucket{job="my-service", le="0.1"}[5m])) / sum(rate(http_server_resp_time_count{job="my-service"}[5m])) < 0.99`,
+		`@resp_time_below:0.025,5m,0.75_unless_@resp_time_above:0.1,5m,0.99`,
+		map[string]string{"summary": "not-again"},
+		map[string]string{"receiver": "system", "service": "ugly-service"},
+	}
+	expected := prometheus.Alert{
+		AlertAnnotations:   testData.annotations,
+		AlertFor:           "my-for",
+		AlertIf:            testData.expected,
+		AlertLabels:        testData.labels,
+		AlertName:          "my-alert",
+		AlertNameFormatted: "myservice_myalert",
+		ServiceName:        "my-service",
+		Replicas:           3,
+	}
+	rwMock := ResponseWriterMock{}
+	addr := fmt.Sprintf(
+		"/v1/docker-flow-monitor?serviceName=%s&alertName=%s&alertIf=%s&alertFor=%s&replicas=3&alertAnnotations=summary=not-again&alertLabels=service=ugly-service,receiver=system",
+		expected.ServiceName,
+		expected.AlertName,
+		testData.shortcut,
+		expected.AlertFor,
+	)
+	req, _ := http.NewRequest("GET", addr, nil)
+
+	serve := New()
+	serve.ReconfigureHandler(rwMock, req)
+
+	s.Equal(expected, serve.alerts[expected.AlertNameFormatted])
+}
+
 func (s *ServerTestSuite) Test_ReconfigureHandler_DoesNotExpandAnnotationsAndLabels_WhenTheyAreAlreadySet() {
 	testData := struct {
 		expected    string