Move server to services pkg

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

services/server/server_linux.go

@@ -0,0 +1,54 @@
+/*
+   Copyright The containerd 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 (
+	"context"
+	"os"
+
+	"github.com/containerd/cgroups"
+	"github.com/containerd/containerd/log"
+	"github.com/containerd/containerd/sys"
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+// apply sets config settings on the server process
+func apply(ctx context.Context, config *Config) error {
+	if config.OOMScore != 0 {
+		log.G(ctx).Debugf("changing OOM score to %d", config.OOMScore)
+		if err := sys.SetOOMScore(os.Getpid(), config.OOMScore); err != nil {
+			log.G(ctx).WithError(err).Errorf("failed to change OOM score to %d", config.OOMScore)
+		}
+	}
+	if config.Cgroup.Path != "" {
+		cg, err := cgroups.Load(cgroups.V1, cgroups.StaticPath(config.Cgroup.Path))
+		if err != nil {
+			if err != cgroups.ErrCgroupDeleted {
+				return err
+			}
+			if cg, err = cgroups.New(cgroups.V1, cgroups.StaticPath(config.Cgroup.Path), &specs.LinuxResources{}); err != nil {
+				return err
+			}
+		}
+		if err := cg.Add(cgroups.Process{
+			Pid: os.Getpid(),
+		}); err != nil {
+			return err
+		}
+	}
+	return nil
+}