Added a script to drain and kill a marathon app as gracefully as possible

paasta_tools/bounce_lib.py

@@ -370,4 +370,21 @@ def downthenup_bounce(
         "tasks_to_drain": set.union(set(), *old_app_live_tasks.values()),
     }
 
+
+@register_bounce_method('down')
+def down_bounce(
+    new_config,
+    new_app_running,
+    happy_new_tasks,
+    old_app_live_tasks,
+):
+    """
+    Stops old apps, doesn't start any new apps.
+    Used for the graceful_app_drain script.
+    """
+    return {
+        "create_app": False,
+        "tasks_to_drain": set(*old_app_live_tasks.values()),
+    }
+
 # vim: tabstop=4 expandtab shiftwidth=4 softtabstop=4

paasta_tools/graceful_app_drain.py

@@ -0,0 +1,99 @@
+#!/usr/bin/env python
+
+import argparse
+import sys
+import time
+
+import service_configuration_lib
+from paasta_tools import marathon_tools
+from paasta_tools import drain_lib
+from paasta_tools import bounce_lib
+from paasta_tools.utils import decompose_job_id
+from paasta_tools.setup_marathon_job import do_bounce, get_old_live_draining_tasks
+from paasta_tools.utils import load_system_paasta_config
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(
+        description="""This script attempts to gracefully drain and kill a marathon app.
+        It is intended for use in emergencies when the regular bounce script can't proceed,
+        and needs to kill a specific app to get going.""",
+    )
+    parser.add_argument(
+        'appname',
+        help="the app that will be drained",
+    )
+    parser.add_argument(
+        '-d', '--soa-dir',
+        dest="soa_dir",
+        metavar="SOA_DIR",
+        default=service_configuration_lib.DEFAULT_SOA_DIR,
+        help="define a different soa config directory",
+    )
+    return parser.parse_args()
+
+
+def main():
+    args = parse_args()
+    full_appid = args.appname.lstrip('/')
+    soa_dir = args.soa_dir
+    marathon_config = marathon_tools.load_marathon_config()
+    client = marathon_tools.get_marathon_client(
+        url=marathon_config.get_url(),
+        user=marathon_config.get_username(),
+        passwd=marathon_config.get_password(),
+    )
+
+    if not marathon_tools.is_app_id_running(app_id=full_appid, client=client):
+        print("Couldn't find an app named {0}".format(full_appid))
+        sys.exit(1)
+
+    service, instance, _, __ = (s.replace('--', '_') for s in decompose_job_id(full_appid))
+    complete_config = marathon_tools.create_complete_config(service, instance, marathon_config)
+    cluster = load_system_paasta_config().get_cluster()
+    service_instance_config = marathon_tools.load_marathon_service_config(
+        service=service,
+        instance=instance,
+        cluster=cluster,
+        soa_dir=soa_dir,
+    )
+    nerve_ns = service_instance_config.get_nerve_namespace()
+    service_namespace_config = marathon_tools.load_service_namespace_config(service=service, namespace=nerve_ns)
+    drain_method = drain_lib.get_drain_method(
+        service_instance_config.get_drain_method(service_namespace_config),
+        service=service,
+        instance=instance,
+        nerve_ns=nerve_ns,
+        drain_method_params=service_instance_config.get_drain_method_params(service_namespace_config),
+    )
+
+    bounce_func = bounce_lib.get_bounce_method_func('down')
+
+    while marathon_tools.is_app_id_running(app_id=full_appid, client=client):
+        app_to_kill = client.get_app(full_appid)
+        old_app_live_tasks, old_app_draining_tasks = get_old_live_draining_tasks([app_to_kill], drain_method)
+        do_bounce(
+            bounce_func=bounce_func,
+            drain_method=drain_method,
+            config=complete_config,
+            new_app_running='',
+            happy_new_tasks=[],
+            old_app_live_tasks=old_app_live_tasks,
+            old_app_draining_tasks=old_app_draining_tasks,
+            serviceinstance="{0}.{1}".format(service, instance),
+            bounce_method='down',
+            service=service,
+            cluster=cluster,
+            instance=instance,
+            marathon_jobid=full_appid,
+            client=client,
+            soa_dir=soa_dir,
+        )
+
+        print "Sleeping for 10 seconds to give the tasks time to drain"
+        time.sleep(10)
+
+    print("Sucessfully killed {0}".format(full_appid))
+
+if __name__ == '__main__':
+    main()