monwork - make updates for nodes and commands

This change triggers updates for checks when a node or command was
updated. This way everything gets adjusted without much work.

cmd/monwork/main.go

@@ -47,6 +47,8 @@ func main() {
 		log.Fatalf("could not open database connection: %s", err)
 	}
 
+	go startNodeGen(db, checkInterval)
+	go startCommandGen(db, checkInterval)
 	go startConfigGen(db, checkInterval)
 
 	// don't exit, we have work to do
@@ -55,6 +57,58 @@ func main() {
 	wg.Wait()
 }
 
+func startNodeGen(db *sql.DB, checkInterval time.Duration) {
+	for {
+		tx, err := db.Begin()
+		if err != nil {
+			log.Printf("could not create transaction: %s", err)
+			time.Sleep(checkInterval)
+			continue
+		}
+		_, err = tx.Exec(`update checks c
+		set updated = n.updated
+		from nodes n
+		where c.node_id = n.id
+			and c.last_refresh < n.updated;`)
+		if err != nil {
+			log.Printf("could not update nodes: %s", err)
+			tx.Rollback()
+			time.Sleep(checkInterval)
+		}
+		if err := tx.Commit(); err != nil {
+			log.Printf("could not commit node updates: %s", err)
+			tx.Rollback()
+		}
+		time.Sleep(checkInterval)
+	}
+}
+
+func startCommandGen(db *sql.DB, checkInterval time.Duration) {
+	for {
+		tx, err := db.Begin()
+		if err != nil {
+			log.Printf("could not create transaction: %s", err)
+			time.Sleep(checkInterval)
+			continue
+		}
+		_, err = tx.Exec(`update checks c
+		set updated = co.updated
+		from commands co
+		where c.command_id = co.id
+			and c.last_refresh < co.updated;`)
+		if err != nil {
+			log.Printf("could not update checks: %s", err)
+			tx.Rollback()
+			time.Sleep(checkInterval)
+		}
+		if err := tx.Commit(); err != nil {
+			log.Printf("could not commit command updates: %s", err)
+			tx.Rollback()
+		}
+		time.Sleep(checkInterval)
+	}
+}
+
 func startConfigGen(db *sql.DB, checkInterval time.Duration) {
 	for {
 		tx, err := db.Begin()