add pause_processing managemenet command

Author: avrohomgottlieb

api/scpca_portal/management/commands/pause_processing.py

@@ -0,0 +1,27 @@
+import logging
+
+from django.core.management.base import BaseCommand
+from django.template.defaultfilters import pluralize
+
+from scpca_portal.models import Job
+
+logger = logging.getLogger()
+logger.setLevel(logging.INFO)
+logger.addHandler(logging.StreamHandler())
+
+
+class Command(BaseCommand):
+    help = """Pauses all processing jobs and adds them to the pending queue."""
+
+    def handle(self, *args, **kwargs):
+        self.pause_processing()
+
+    def pause_processing(self):
+        terminated_jobs = Job.terminate_processing(reason="Processing paused on re-deploy.")
+        retry_jobs = Job.create_retry_jobs(terminated_jobs)
+
+        retry_job_count = len(retry_jobs)
+        logger.info(
+            f"{retry_job_count} processing job{pluralize(retry_job_count)} were paused "
+            "and added to the pending queue before deploy."
+        )