find ucloud -name \*.py -exec sed -i "s/ucloud/uncloud/g" {} \;

uncloud/scheduler/main.py

@@ -0,0 +1,75 @@
+# TODO
+#  1. send an email to an email address defined by env['admin-email']
+#     if resources are finished
+#  2. Introduce a status endpoint of the scheduler -
+#     maybe expose a prometheus compatible output
+
+from ucloud.common.request import RequestEntry, RequestType
+from ucloud.shared import shared
+from ucloud.settings import settings
+from .helper import (
+    dead_host_mitigation,
+    dead_host_detection,
+    assign_host,
+    NoSuitableHostFound,
+)
+from . import logger
+
+
+def main():
+    for request_iterator in [
+        shared.etcd_client.get_prefix(
+            settings["etcd"]["request_prefix"], value_in_json=True
+        ),
+        shared.etcd_client.watch_prefix(
+            settings["etcd"]["request_prefix"],
+            timeout=5,
+            value_in_json=True,
+        ),
+    ]:
+        for request_event in request_iterator:
+            request_entry = RequestEntry(request_event)
+            # Never Run time critical mechanism inside timeout
+            # mechanism because timeout mechanism only comes
+            # when no other event is happening. It means under
+            # heavy load there would not be a timeout event.
+            if request_entry.type == "TIMEOUT":
+
+                # Detect hosts that are dead and set their status
+                # to "DEAD", and their VMs' status to "KILLED"
+                dead_hosts = dead_host_detection()
+                if dead_hosts:
+                    logger.debug("Dead hosts: %s", dead_hosts)
+                    dead_host_mitigation(dead_hosts)
+
+            elif request_entry.type == RequestType.ScheduleVM:
+                print(request_event.value)
+                logger.debug(
+                    "%s, %s", request_entry.key, request_entry.value
+                )
+
+                vm_entry = shared.vm_pool.get(request_entry.uuid)
+                if vm_entry is None:
+                    logger.info(
+                        "Trying to act on {} but it is deleted".format(
+                            request_entry.uuid
+                        )
+                    )
+                    continue
+                shared.etcd_client.client.delete(
+                    request_entry.key
+                )  # consume Request
+
+                try:
+                    assign_host(vm_entry)
+                except NoSuitableHostFound:
+                    vm_entry.add_log(
+                        "Can't schedule VM. No Resource Left."
+                    )
+                    shared.vm_pool.put(vm_entry)
+
+                    logger.info("No Resource Left. Emailing admin....")
+
+
+if __name__ == "__main__":
+    main()