Files
2023-05-23 19:32:04 +02:00

128 lines
3.4 KiB
Go

package main
import (
"context"
"fmt"
"io"
"os"
"os/signal"
"syscall"
"time"
"github.com/alecthomas/kingpin/v2"
"github.com/multiplay/go-slack/chat"
"github.com/multiplay/go-slack/webhook"
"github.com/robfig/cron"
v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/client-go/kubernetes"
batchv1 "k8s.io/client-go/kubernetes/typed/batch/v1"
"k8s.io/client-go/rest"
)
var checkFunc = doCheck
var exitFunc = os.Exit
func main() {
slackUrl := kingpin.Flag("slack-url", "The Slack Webhook URL").Envar("SLACK_URL").Required().String()
kingpin.Parse()
exitFunc(doMain(*slackUrl, &DefaultProvider{&InClusterProvider{}}))
}
func doMain(slackUrl string, provider ClientProvider) int {
client, err := provider.Provide()
if err != nil {
fmt.Printf("Unable to connect to K8S: %s\n", err)
return 1
}
ic := make(chan os.Signal, 1)
signal.Notify(ic, os.Interrupt, syscall.SIGTERM)
if err := checkFunc(client, slackUrl, ic, 60*time.Second, os.Stdout); err != nil {
fmt.Printf("Error checking jobs: %s\n", err)
return 1
}
return 0
}
func doCheck(client Client, slackUrl string, ic chan os.Signal, sleepTime time.Duration, out io.Writer) error {
slack := webhook.New(slackUrl)
parser := cron.NewParser(cron.Minute | cron.Hour | cron.Dom | cron.Month | cron.Dow)
for {
select {
case <-ic:
_, _ = fmt.Fprintf(out, "Got SIGTERM signal, exiting\n")
return nil
default:
cronJobs, err := client.BatchV1().CronJobs("").List(context.Background(), v1.ListOptions{})
if err != nil {
return fmt.Errorf("error getting cronjobs: %w", err)
}
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 {
return fmt.Errorf("error parsing schedule of %s/%s (%s): %w", c.Namespace, c.Name, c.Spec.Schedule, err)
}
next := schedule.Next(since.Time)
_, _ = fmt.Fprintf(out, "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.Fprintf(out, "%s/%s was not scheduled. Sending Slack notification.\n", c.Namespace, 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",
}
_, err := m.Send(slack)
if err != nil {
_, _ = fmt.Fprintf(out, "Unable to send Slack notification: %s\n", err)
}
}
}
}
time.Sleep(sleepTime)
}
}
}
type Client interface {
BatchV1() batchv1.BatchV1Interface
}
type ClientProvider interface {
Provide() (Client, error)
}
type DefaultProvider struct {
provider ConfigProvider
}
func (d DefaultProvider) Provide() (Client, error) {
config, err := d.provider.Provide()
if err != nil {
return nil, err
}
return kubernetes.NewForConfig(config)
}
var _ ClientProvider = &DefaultProvider{}
type ConfigProvider interface {
Provide() (*rest.Config, error)
}
type InClusterProvider struct{}
func (i InClusterProvider) Provide() (*rest.Config, error) {
return rest.InClusterConfig()
}
var _ ConfigProvider = &InClusterProvider{}