Generate job artifacts in an initContainer and export the files to workstation afterwards.

export-files-job.yaml

# Allows copying of job files to local after execution. Example copy command:

apiVersion: batch/v1
kind: Job
metadata:
  name: export-files-job
spec:
  template:
    metadata:
      labels:
        job-name: export-files-job
    spec:
      restartPolicy: Never
      volumes:
        - name: job-files
          emptyDir: {}
      initContainers:
        - name: job
          image: alpine
          volumeMounts:
            - name: job-files
              mountPath: /job
          workingDir: /job
          command: [/bin/sh, -c]
          args:
            - |
              echo "This is where your job would happen. The log from this job is"
              echo "is visible with 'kubectl logs POD job'."

              echo "Imagine the files below are generated from the job."
              echo contents of a file I want from a job container > ./file-1.txt
              date > ./file-2.txt
              hostname > ./file-3.txt
              
              echo "Now this initContainer will exit and the container below will start"
              echo "and sit idle so that these job files can be streamed out of the pod."
      containers:
        - name: export-files
          image: alpine
          volumeMounts:
            - name: job-files
              mountPath: /job
          workingDir: /job
          command: [/bin/sh, -c]
          args:
            - |
              echo "Using 'set -e' to fail on errors"
              set -e
              echo "Creating the fifo pipe to send the data"
              mkfifo /export-pipe
              echo "Tarring the correct files and piping them to the std of the pipe"
              echo "You'll need to stream them out with kubectl for this pod to shutdown"
              tar -cvf - $(find . -type f) | /export-pipe
              echo "The files have been read, so the previous command to pipe them stopped blocking"

grab-files.sh

#!/bin/bash

echo "Using 'set -e' to be strict about errors"
set -e

JOB_NAME=$1
DEST_DIR=$2

echo "Looking up the pod name"

POD_NAME=$(kubectl get pods --selector="job-name=$JOB_NAME" -o=jsonpath="{.items[0].metadata.name}")

echo "Creating the destination folder
mkdir -p $DEST_DIR || true

echo "Waiting for results to be available from $POD_NAME"
kubectl wait --timeout=600s --for=condition=ContainersReady pod/$POD_NAME

echo "Fetching results"
echo "Reading the stdout of the fifo pipe via 'kubectl exec'"
echo " and then piping the kubectl output into tar to expand the files again"
kubectl exec $POD_NAME -c export-files -- bash -c 'cat /export_pipe' | tar -C $DEST_DIR -xvf -

run-it.sh

#!/bin/bash

# Start the job
kubectl apply -f export-job-files.yaml

# Use the script to wait for the job (named "export-files-job") and then unpack the copied files into the "output folder"
./grab-files export-files-job output

Awesome! Thanks.