Move unix specific logic into _unix.go

Signed-off-by: Lantao Liu <lantaol@google.com>

pkg/server/container_update_resources_unix.go

@@ -0,0 +1,148 @@
+// +build !windows
+
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package server
+
+import (
+	gocontext "context"
+
+	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/containers"
+	"github.com/containerd/containerd/errdefs"
+	"github.com/containerd/containerd/log"
+	"github.com/containerd/typeurl"
+	runtimespec "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/pkg/errors"
+	"golang.org/x/net/context"
+	runtime "k8s.io/cri-api/pkg/apis/runtime/v1alpha2"
+
+	"github.com/containerd/cri/pkg/containerd/opts"
+	ctrdutil "github.com/containerd/cri/pkg/containerd/util"
+	containerstore "github.com/containerd/cri/pkg/store/container"
+	"github.com/containerd/cri/pkg/util"
+)
+
+// UpdateContainerResources updates ContainerConfig of the container.
+func (c *criService) UpdateContainerResources(ctx context.Context, r *runtime.UpdateContainerResourcesRequest) (retRes *runtime.UpdateContainerResourcesResponse, retErr error) {
+	container, err := c.containerStore.Get(r.GetContainerId())
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to find container")
+	}
+	// Update resources in status update transaction, so that:
+	// 1) There won't be race condition with container start.
+	// 2) There won't be concurrent resource update to the same container.
+	if err := container.Status.Update(func(status containerstore.Status) (containerstore.Status, error) {
+		return status, c.updateContainerResources(ctx, container, r.GetLinux(), status)
+	}); err != nil {
+		return nil, errors.Wrap(err, "failed to update resources")
+	}
+	return &runtime.UpdateContainerResourcesResponse{}, nil
+}
+
+func (c *criService) updateContainerResources(ctx context.Context,
+	cntr containerstore.Container,
+	resources *runtime.LinuxContainerResources,
+	status containerstore.Status) (retErr error) {
+	id := cntr.ID
+	// Do not update the container when there is a removal in progress.
+	if status.Removing {
+		return errors.Errorf("container %q is in removing state", id)
+	}
+
+	// Update container spec. If the container is not started yet, updating
+	// spec makes sure that the resource limits are correct when start;
+	// if the container is already started, updating spec is still required,
+	// the spec will become our source of truth for resource limits.
+	oldSpec, err := cntr.Container.Spec(ctx)
+	if err != nil {
+		return errors.Wrap(err, "failed to get container spec")
+	}
+	newSpec, err := updateOCILinuxResource(ctx, oldSpec, resources)
+	if err != nil {
+		return errors.Wrap(err, "failed to update resource in spec")
+	}
+
+	if err := updateContainerSpec(ctx, cntr.Container, newSpec); err != nil {
+		return err
+	}
+	defer func() {
+		if retErr != nil {
+			deferCtx, deferCancel := ctrdutil.DeferContext()
+			defer deferCancel()
+			// Reset spec on error.
+			if err := updateContainerSpec(deferCtx, cntr.Container, oldSpec); err != nil {
+				log.G(ctx).WithError(err).Errorf("Failed to update spec %+v for container %q", oldSpec, id)
+			}
+		}
+	}()
+
+	// If container is not running, only update spec is enough, new resource
+	// limit will be applied when container start.
+	if status.State() != runtime.ContainerState_CONTAINER_RUNNING {
+		return nil
+	}
+
+	task, err := cntr.Container.Task(ctx, nil)
+	if err != nil {
+		if errdefs.IsNotFound(err) {
+			// Task exited already.
+			return nil
+		}
+		return errors.Wrap(err, "failed to get task")
+	}
+	// newSpec.Linux won't be nil
+	if err := task.Update(ctx, containerd.WithResources(newSpec.Linux.Resources)); err != nil {
+		if errdefs.IsNotFound(err) {
+			// Task exited already.
+			return nil
+		}
+		return errors.Wrap(err, "failed to update resources")
+	}
+	return nil
+}
+
+// updateContainerSpec updates container spec.
+func updateContainerSpec(ctx context.Context, cntr containerd.Container, spec *runtimespec.Spec) error {
+	any, err := typeurl.MarshalAny(spec)
+	if err != nil {
+		return errors.Wrapf(err, "failed to marshal spec %+v", spec)
+	}
+	if err := cntr.Update(ctx, func(ctx gocontext.Context, client *containerd.Client, c *containers.Container) error {
+		c.Spec = any
+		return nil
+	}); err != nil {
+		return errors.Wrap(err, "failed to update container spec")
+	}
+	return nil
+}
+
+// updateOCILinuxResource updates container resource limit.
+func updateOCILinuxResource(ctx context.Context, spec *runtimespec.Spec, new *runtime.LinuxContainerResources) (*runtimespec.Spec, error) {
+	// Copy to make sure old spec is not changed.
+	var cloned runtimespec.Spec
+	if err := util.DeepCopy(&cloned, spec); err != nil {
+		return nil, errors.Wrap(err, "failed to deep copy")
+	}
+	if cloned.Linux == nil {
+		cloned.Linux = &runtimespec.Linux{}
+	}
+	if err := opts.WithResources(new)(ctx, nil, nil, &cloned); err != nil {
+		return nil, errors.Wrap(err, "unable to set linux container resources")
+	}
+	return &cloned, nil
+}