feat: initial commit

2020-08-26 16:50:59 +02:00
commit d2a946782f
10 changed files with 454 additions and 0 deletions
@@ -0,0 +1,83 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"github.com/multiplay/go-slack/chat"
+	"github.com/multiplay/go-slack/webhook"
+	"github.com/robfig/cron"
+	"gopkg.in/alecthomas/kingpin.v2"
+	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/rest"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+)
+
+func main() {
+	slackUrl := kingpin.Flag("slack-url", "The Slack Webhook URL").Envar("SLACK_URL").Required().String()
+	kingpin.Parse()
+
+	config, err := rest.InClusterConfig()
+	if err != nil {
+		panic(err.Error())
+	}
+	clientset, err := kubernetes.NewForConfig(config)
+	if err != nil {
+		panic(err.Error())
+	}
+
+	slack := webhook.New(*slackUrl)
+
+	parser := cron.NewParser(cron.Minute | cron.Hour | cron.Dom | cron.Month | cron.Dow)
+
+	ic := make(chan os.Signal, 1)
+	signal.Notify(ic, os.Interrupt, syscall.SIGTERM)
+
+	for {
+		select {
+		case <-ic:
+			fmt.Printf("Got SIGTERM signal, exiting\n")
+			break
+		default:
+			cronjobs, err := clientset.BatchV1beta1().CronJobs("").List(context.Background(), v1.ListOptions{})
+			if err != nil {
+				fmt.Printf("Error getting cronjobs: %s", err)
+				os.Exit(1)
+			}
+			limit := time.Now().Add(-120 * time.Second)
+			for _, c := range cronjobs.Items {
+				if c.Spec.Suspend == nil || !*c.Spec.Suspend {
+					since := c.CreationTimestamp
+					if c.Status.LastScheduleTime != nil {
+						since = *c.Status.LastScheduleTime
+					}
+					schedule, err := parser.Parse(c.Spec.Schedule)
+					if err != nil {
+						fmt.Printf("Error parsing schedule of %s/%s (%s): %s", c.Namespace, c.Name, c.Spec.Schedule, err)
+						os.Exit(1)
+					}
+					next := schedule.Next(since.Time)
+					fmt.Printf("Checking %s/%s since %s, next schedule %s, limit %s.\n", c.Namespace, c.Name, since.Format(time.RFC3339), next.Format(time.RFC3339), limit.Format(time.RFC3339))
+					if next.Before(limit) {
+						fmt.Printf("%s was not scheduled. Sending Slack notification.\n", c.Name)
+						m := &chat.Message{
+							Text:     fmt.Sprintf("Cronjob %s/%s is not running according to schedule (%s). Last scheduled: %s", c.Namespace, c.Name, c.Spec.Schedule, since.Format(time.RFC3339)),
+							Username: "cron-checker",
+						}
+						resp, err := m.Send(slack)
+						if err != nil {
+							fmt.Printf("Unable to send Slack notification: %s", err)
+						}
+						if !resp.OK {
+							fmt.Printf("Unable to send Slack notification: %s", resp.Error)
+						}
+					}
+				}
+			}
+			time.Sleep(60 * time.Second)
+		}
+	}
+}