Add events to service detail page

core/event.go

@@ -0,0 +1,26 @@
+package core
+
+import "time"
+
+// Event is something that happens at a specific time
+type Event struct {
+	// Type is the kind of event
+	Type EventType `json:"type"`
+
+	// Timestamp is the moment at which the event happened
+	Timestamp time.Time `json:"timestamp"`
+}
+
+// EventType is, uh, the types of events?
+type EventType string
+
+var (
+	// EventStart is a type of event that represents when a service starts being monitored
+	EventStart EventType = "START"
+
+	// EventHealthy is a type of event that represents a service passing all of its conditions
+	EventHealthy EventType = "HEALTHY"
+
+	// EventUnhealthy is a type of event that represents a service failing one or more of its conditions
+	EventUnhealthy EventType = "UNHEALTHY"
+)

core/service-status.go

@@ -1,6 +1,10 @@
 package core
 
-import "github.com/TwinProduction/gatus/util"
+import (
+	"time"
+
+	"github.com/TwinProduction/gatus/util"
+)
 
 // ServiceStatus contains the evaluation Results of a Service
 type ServiceStatus struct {
@@ -16,6 +20,13 @@ type ServiceStatus struct {
 	// Results is the list of service evaluation results
 	Results []*Result `json:"results"`
 
+	// Events is a list of events
+	//
+	// We don't expose this through JSON, because the main dashboard doesn't need to have these events.
+	// However, the detailed service page does leverage this by including it to a map that will be
+	// marshalled alongside the ServiceStatus.
+	Events []*Event `json:"-"`
+
 	// Uptime information on the service's uptime
 	Uptime *Uptime `json:"uptime"`
 }
@@ -27,13 +38,33 @@ func NewServiceStatus(service *Service) *ServiceStatus {
 		Group:   service.Group,
 		Key:     util.ConvertGroupAndServiceToKey(service.Group, service.Name),
 		Results: make([]*Result, 0),
-		Uptime:  NewUptime(),
+		Events: []*Event{{
+			Type:      EventStart,
+			Timestamp: time.Now(),
+		}},
+		Uptime: NewUptime(),
 	}
 }
 
 // AddResult adds a Result to ServiceStatus.Results and makes sure that there are
 // no more than 20 results in the Results slice
 func (ss *ServiceStatus) AddResult(result *Result) {
+	if len(ss.Results) > 0 {
+		// Check if there's any change since the last result
+		// OR there's only 1 event, which only happens when there's a start event
+		if ss.Results[len(ss.Results)-1].Success != result.Success || len(ss.Events) == 1 {
+			event := &Event{Timestamp: result.Timestamp}
+			if result.Success {
+				event.Type = EventHealthy
+			} else {
+				event.Type = EventUnhealthy
+			}
+			ss.Events = append(ss.Events, event)
+			if len(ss.Events) > 20 {
+				ss.Events = ss.Events[1:]
+			}
+		}
+	}
 	ss.Results = append(ss.Results, result)
 	if len(ss.Results) > 20 {
 		ss.Results = ss.Results[1:]