Distinct "internal" Event Types

It was ambiguous what the "internal" event type especially stand for. As
currently both of its use cases are some kind of reevaluation - either
during the program's startup or due to an event's age -, it was renamed
to "incident-age".

To ensure database-level stability, the column type was changed from
text to a custom enum.

Closes #162.

internal/event/event.go

@@ -37,17 +37,19 @@ type Event struct {
 	ID int64 `json:"-"`
 }
 
+// Please keep the following types in alphabetically order and, even more important, make sure that the database type
+// event_type reflects the same values.
 const (
-	TypeState                  = "state"
-	TypeAcknowledgementSet     = "acknowledgement-set"
 	TypeAcknowledgementCleared = "acknowledgement-cleared"
-	TypeInternal               = "internal"
+	TypeAcknowledgementSet     = "acknowledgement-set"
+	TypeCustom                 = "custom"
+	TypeDowntimeEnd            = "downtime-end"
 	TypeDowntimeRemoved        = "downtime-removed"
 	TypeDowntimeStart          = "downtime-start"
-	TypeDowntimeEnd            = "downtime-end"
-	TypeCustom                 = "custom"
-	TypeFlappingStart          = "flapping-start"
 	TypeFlappingEnd            = "flapping-end"
+	TypeFlappingStart          = "flapping-start"
+	TypeIncidentAge            = "incident-age"
+	TypeState                  = "state"
 )
 
 // Validate validates the current event state.
@@ -68,16 +70,17 @@ func (e *Event) Validate() error {
 	switch e.Type {
 	case "":
 		return fmt.Errorf("invalid event: 'type' must not be empty")
-	case TypeState,
-		TypeAcknowledgementSet,
+	case
 		TypeAcknowledgementCleared,
-		TypeInternal,
+		TypeAcknowledgementSet,
+		TypeCustom,
+		TypeDowntimeEnd,
 		TypeDowntimeRemoved,
 		TypeDowntimeStart,
-		TypeDowntimeEnd,
-		TypeCustom,
+		TypeFlappingEnd,
 		TypeFlappingStart,
-		TypeFlappingEnd:
+		TypeIncidentAge,
+		TypeState:
 		return nil
 	default:
 		return fmt.Errorf("invalid event: unsupported event type %q", e.Type)

internal/incident/incident.go

@@ -455,8 +455,8 @@ func (i *Incident) evaluateEscalations(eventTime time.Time) ([]*rule.Escalation,
 			i.logger.Info("Reevaluating escalations")
 
 			i.RetriggerEscalations(&event.Event{
-				Type:    event.TypeInternal,
 				Time:    nextEvalAt,
+				Type:    event.TypeIncidentAge,
 				Message: fmt.Sprintf("Incident reached age %v", nextEvalAt.Sub(i.StartedAt.Time())),
 			})
 		})

internal/incident/incidents.go

@@ -128,8 +128,8 @@ func LoadOpenIncidents(ctx context.Context, db *database.DB, logger *logging.Log
 
 						i.RetriggerEscalations(&event.Event{
 							Time:    time.Now(),
-							Type:    event.TypeInternal,
-							Message: "Incident reevaluation at daemon startup",
+							Type:    event.TypeIncidentAge,
+							Message: fmt.Sprintf("Incident reached age %v (daemon was restarted)", time.Since(i.StartedAt.Time())),
 						})
 					}
 

schema/pgsql/schema.sql

@@ -219,13 +219,25 @@ CREATE TABLE object_extra_tag (
     CONSTRAINT pk_object_extra_tag PRIMARY KEY (object_id, tag)
 );
 
+CREATE TYPE event_type AS ENUM (
+    'acknowledgement-cleared',
+    'acknowledgement-set',
+    'custom',
+    'downtime-end',
+    'downtime-removed',
+    'downtime-start',
+    'flapping-end',
+    'flapping-start',
+    'incident-age',
+    'state'
+);
 CREATE TYPE severity AS ENUM ('ok', 'debug', 'info', 'notice', 'warning', 'err', 'crit', 'alert', 'emerg');
 
 CREATE TABLE event (
     id bigserial,
     time bigint NOT NULL,
     object_id bytea NOT NULL REFERENCES object(id),
-    type text NOT NULL,
+    type event_type NOT NULL,
     severity severity,
     message text,
     username citext,

schema/pgsql/upgrades/030.sql

@@ -0,0 +1,16 @@
+CREATE TYPE event_type AS ENUM (
+    'acknowledgement-cleared',
+    'acknowledgement-set',
+    'custom',
+    'downtime-end',
+    'downtime-removed',
+    'downtime-start',
+    'flapping-end',
+    'flapping-start',
+    'incident-age',
+    'state'
+    );
+
+UPDATE event SET type = 'incident-age' WHERE type = 'internal';
+
+ALTER TABLE event ALTER COLUMN type TYPE event_type USING type::event_type;