Custom Strategies

from watcher.decision_engine.strategy.strategies import base

class MyCustomStrategy(base.BaseStrategy):
    """Placement strategy for specialized workloads."""

    NAME = "my_custom_strategy"
    DISPLAY_NAME = "My Custom Strategy"
    GOAL_NAME = "server_consolidation"  # Associate with an existing goal

    def pre_execute(self):
        """Called before the main analysis — validate data sources."""
        pass

    def do_execute(self, audit):
        """Main analysis loop — build the action plan."""
        cluster_model = self.compute_model
        for host in cluster_model.compute_nodes.values():
            if self._is_underutilized(host):
                self._migrate_instances_from(host)

    def post_execute(self):
        """Called after analysis — cleanup."""
        pass

    def _is_underutilized(self, host):
        used_vcpu = host.vcpus - host.free_disk_gb  # Example metric
        return used_vcpu / host.vcpus < 0.15

    def _migrate_instances_from(self, source_host):
        for instance in self.compute_model.mapping.get_node_instances(source_host):
            self.solution.add_action(
                action_type="migrate",
                input_parameters={
                    "source_node": source_host.hostname,
                    "destination_node": self._find_target_host(instance),
                    "migration_type": "live"
                }
            )

[entry_points]
watcher_strategies =
    my_custom_strategy = mypackage.strategies:MyCustomStrategy

pip install -e /path/to/mypackage

docker cp /path/to/mypackage/ watcher_decision_engine:/opt/mypackage/
docker exec watcher_decision_engine pip install /opt/mypackage/

docker restart watcher_decision_engine

watcher strategy list

watcher goal list

[entry_points]
watcher_goals =
    my_custom_goal = mypackage.goals:MyCustomGoal

watcher_strategies =
    my_custom_strategy = mypackage.strategies:MyCustomStrategy

watcher audit create \
  --goal server_consolidation \
  --strategy my_custom_strategy \
  --name custom-strategy-test

watcher audit show custom-strategy-test

watcher actionplan list \
  --audit <audit-uuid>