I am working on integrating a few Laravel PHP applications into a new Kubernetes architecture, and still struggling on how I can run php artisan schedule:run in a nice manner.

In the official Laravel manual, we are advised to set up the cronjob like this.

* * * * * cd /path-to-your-project && php artisan schedule:run >> /dev/null 2>&1

ref. https://readouble.com/laravel/5.7/en/scheduling.html

Cronjob

Initially, I came up with the idea of using cronjob in Kubernetes, and it works fine for now but started worried about the current architecture.

(One deployment for web service, and one cronjob for the task scheduling.)

---
apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: cron
  namespace: my-laravel-app
spec:
  concurrencyPolicy: Replace
  schedule: "*/1 * * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - image: my_laravel_app_image:latest
            name: cron
            command: ["php", "artisan", "schedule:run"]
            imagePullPolicy: Always
            envFrom:
            - configMapRef:
                name: laravel-app-config
            - secretRef:
                name: laravel-app-secret
          restartPolicy: Never

However, since I use concurrencyPolicy: Replace here the pod itself might be terminated even the job is still running (for more than 1 minute). To avoid this issue, I could use the default value concurrencyPolicy: Allow but it introduces another issue - Even I set failedJobsHistoryLimit at 1 and successfulJobsHistoryLimit at 1 the pod associated with the job are not properly terminated in the current running in-house Kubernetes cluster, and it reaches quota limit.

NAME                        READY   STATUS      RESTARTS   AGE
pod/test-cronjob-a           0/1     Completed   0          4m30s
pod/test-cronjob-b           0/1     Completed   0          3m30s
pod/test-cronjob-c           0/1     Completed   0          2m29s
pod/test-cronjob-d           0/1     Completed   0          88s
pod/test-cronjob-e           0/1     Completed   0          28s

ref. https://github.com/kubernetes/kubernetes/issues/74741#issuecomment-712707783

Also, I feel It's a bit tricky to configure the monitoring and logging stack for those one-off jobs.

Deployment

Instead of using cronjob, I'm thinking to try to deploy the scheduler as another pod having the cron setting in the container using deployment resource.

(One deployment for web service, and one deployment for the task scheduling.)

I just wonder how you guys normally work around this issue in a scalable manner.