Function InstancePlacementRun

internal/server/scriptlet/instance_placement.go:25–519

InstancePlacementRun runs the instance placement scriptlet and returns the chosen cluster member target.

(ctx context.Context, l logger.Logger, s *state.State, req *apiScriptlet.InstancePlacement, candidateMembers []db.NodeInfo, leaderAddress string)

// InstancePlacementRun runs the instance placement scriptlet and returns the chosen cluster member target.
func InstancePlacementRun(ctx context.Context, l logger.Logger, s *state.State, req *apiScriptlet.InstancePlacement, candidateMembers []db.NodeInfo, leaderAddress string) (*db.NodeInfo, error) {
	ctx, cancel := context.WithCancel(ctx)
	defer cancel()

	logFunc := log.CreateLogger(l, "Instance placement scriptlet")

	var targetMember *db.NodeInfo

	setTargetFunc := func(thread *starlark.Thread, b *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) {
		var memberName string

		err := starlark.UnpackArgs(b.Name(), args, kwargs, "member_name", &memberName)
		if err != nil {
			return nil, err
		}

		for i := range candidateMembers {
			if candidateMembers[i].Name == memberName {
				targetMember = &candidateMembers[i]
				break
			}
		}

		if targetMember == nil {
			l.Error("Instance placement scriptlet set invalid member target", logger.Ctx{"member": memberName})
			return nil, fmt.Errorf("Invalid member name: %s", memberName)
		}

		l.Info("Instance placement scriptlet set member target", logger.Ctx{"member": targetMember.Name})

		return starlark.None, nil
	}

	getClusterMemberResourcesFunc := func(thread *starlark.Thread, b *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) {
		var memberName string

		err := starlark.UnpackArgs(b.Name(), args, kwargs, "member_name", &memberName)
		if err != nil {
			return nil, err
		}

		var res *api.Resources

		// Get the local resource usage.
		if memberName == s.ServerName {
			res, err = resources.GetResources()
			if err != nil {
				return nil, err
			}
		} else {
			// Get remote member resource usage.
			var targetMember *db.NodeInfo
			for i := range candidateMembers {
				if candidateMembers[i].Name == memberName {
					targetMember = &candidateMembers[i]
					break
				}
			}