How to run containers sequentially as a Kubernetes job?

Question

I'm trying to replace my legacy job scheduler with Kubernetes job and wondering how to write sequential jobs as a Kubernetes job.

First, I wrote the following script to execute job1 and job2 in the written order but it didn't work as I expected.

apiVersion: batch/v1 kind: Job metadata:   name: sequential spec:   activeDeadlineSeconds: 100   template:     metadata:       name: sequential_jobs     spec:       containers:       - name: job1         image: image1       - name: job2         image: image2       restartPolicy: Never 

The job described above seems to run job1 and job2 in parallel. Is there any good way to run job1 and job2 in the written order?

Appended.

I recently found https://github.com/argoproj/argo very good for my usecase.

Answer 1

After a few attempts, I did this and that solved the basic problem (similar to what the OP has posted). This configuration ensures that job-1 completes before job-2 begins. If job-1 fails, job-2 container is not started. I still need to work on the retries and failure handling, but the basics works. Hopefully, this will help others:

apiVersion: v1 kind: Pod metadata:   name: sequential-job spec:   initContainers:   - name: job-1     image: busybox     # runs for 15 seconds; echoes job name and timestamp     command: ['sh', '-c', 'for i in 1 2 3; do echo "job-1 `date`" && sleep 5s; done;']   - name: job-2     image: busybox     # runs for 15 seconds; echoes job name and timestamp     command: ['sh', '-c', 'for i in 1 2 3; do echo "job-2 `date`" && sleep 5s; done;']   # I don't really need the 'containers', but syntax requires    # it so, I'm using it as a place where I can report the    # completion status   containers:   - name: job-done     image: busybox     command: ['sh', '-c', 'echo "job-1 and job-2 completed"']   restartPolicy: Never 

Update

The same configuration as above also works inside a Job spec:

apiVersion: batch/v1 kind: Job metadata:   name: sequential-jobs spec:   template:     metadata:       name: sequential-job     spec:       initContainers:       - name: job-1         image: busybox         command: ['sh', '-c', 'for i in 1 2 3; do echo "job-1 `date`" && sleep 5s; done;']       - name: job-2         image: busybox         command: ['sh', '-c', 'for i in 1 2 3; do echo "job-2 `date`" && sleep 5s; done;']       containers:       - name: job-done         image: busybox         command: ['sh', '-c', 'echo "job-1 and job-2 completed"']       restartPolicy: Never