Kubernetes Cron-Job Slack Notification - kubernetes

Question

I have a cronjob which creates postgres backup job.. I would like to send notification to slack channels via webhook with cronjob status fail or success. How can I add a condition or specify the status of Job and sending to slack? I suppose that also below curl request will work but please warn if you see any fault.
kind: CronJob
metadata:
name: standup
spec:
schedule: "* 17 * * 1-5"
jobTemplate:
spec:
template:
spec:
containers:
- name: standup
image: busybox
resources:
requests:
cpu: 1m
memory: 100Mi
env:
- args: /bin/sh
- -c
- curl -X POST -H 'Content-type: application/json' --data '{"text":"Hello, World!"}' https://hooks.slack.com/services/TQPCENFHP/
restartPolicy: OnFailure
~ semural$ kubectl logs $pods -n database
The following backups are available in specified backup path:
Added `s3` successfully.
[2020-04-13 14:24:46 UTC] 0B postgresql-cluster/
NAME SCHEDULE SUSPEND ACTIVE LAST SCHEDULE AGE
postgresql-postgresql-helm-backup 0 0 * * * False 0 8h 18h
NAME COMPLETIONS DURATION AGE
postgresql-postgresql-helm-backup-1586822400 1/1 37s 8h
postgresql-postgresql-helm-backup-list 1/1 2s 18h
postgresql-postgresql-helm-pgmon 1/1 49s 18h

Answer 1

I think we can create a simple script to get the cronjob status:
import json
import os
from kubernetes import client, config, utils
from kubernetes.client.rest import ApiException
from api.exceptions import BatchApiNamespaceNotExistedException
class Constants:
BACKOFF_LIMIT = 1
STATUS_RUNNING = "RUNNING"
STATUS_SUCCEED = "SUCCEED"
STATUS_FAILED = "FAILED"
STATUS_NOT_FOUND = "NOT FOUND"
class KubernetesApi:
def __init__(self):
try:
config.load_incluster_config()
except:
config.load_kube_config()
self.configuration = client.Configuration()
self.api_instance = client.BatchV1Api(client.ApiClient(self.configuration))
self.api_instance_v1_beta = client.BatchV1beta1Api(client.ApiClient(self.configuration))
def get_job_status(self, job):
if job is not None:
total_failed_pod = job.status.failed or 0
total_succeeded_pod = job.status.succeeded or 0
if total_failed_pod + total_succeeded_pod < Constants.BACKOFF_LIMIT:
return Constants.STATUS_RUNNING
elif total_succeeded_pod > 0:
return Constants.STATUS_SUCCEED
return Constants.STATUS_FAILED
return Constants.STATUS_NOT_FOUND
def get_cron_job_status(self, namespace):
try:
cron_job_list = self.api_instance_v1_beta.list_namespaced_cron_job(namespace=namespace,
watch=False)
except ApiException as e:
raise BatchApiNamespaceNotExistedException("Exception when calling BatchV1Api->list_namespaced_cron_job: %s\n" % e)
for cron_job in cron_job_list.items:
if cron_job.status.active is not None:
for active_cron_job in cron_job.status.active:
job = self.api_instance.read_namespaced_job(namespace=namespace,
name=active_cron_job.name)
if job_status == Constants.STATUS_FAILED:
# Do whatever you want in there
print(job_status)
So if the status is failed then we can send the log to slack.

Answer 2

I think what you have is already a good start.. Assuming you have the curl command as a script that takes the first argument as the message to be posted you can do something as the following:
kind: CronJob
metadata:
name: standup
spec:
schedule: "* 17 * * 1-5"
jobTemplate:
spec:
template:
spec:
containers:
- name: standup
image: busybox
resources:
requests:
cpu: 1m
memory: 100Mi
env:
- args: /bin/sh
- -c
- run-job.py || notify-cron-job "FAIL" && notify-cron-job "SUCCESS"