devicemapper: seperate implementation pkg from plugin pkg

Signed-off-by: Teemu Kallio <teemu.kallio@pm.me>

cmd/containerd/builtins_devmapper_linux.go

@@ -18,4 +18,4 @@
 
 package main
 
-import _ "github.com/containerd/containerd/snapshots/devmapper"
+import _ "github.com/containerd/containerd/snapshots/devmapper/plugin"

snapshots/devmapper/plugin/plugin.go

@@ -0,0 +1,52 @@
+// +build linux
+
+/*
+   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 plugin
+
+import (
+	"github.com/containerd/containerd/platforms"
+	"github.com/containerd/containerd/plugin"
+	"github.com/containerd/containerd/snapshots/devmapper"
+	"github.com/pkg/errors"
+)
+
+func init() {
+	plugin.Register(&plugin.Registration{
+		Type:   plugin.SnapshotPlugin,
+		ID:     "devmapper",
+		Config: &devmapper.Config{},
+		InitFn: func(ic *plugin.InitContext) (interface{}, error) {
+			ic.Meta.Platforms = append(ic.Meta.Platforms, platforms.DefaultSpec())
+
+			config, ok := ic.Config.(*devmapper.Config)
+			if !ok {
+				return nil, errors.New("invalid devmapper configuration")
+			}
+
+			if config.PoolName == "" {
+				return nil, errors.New("devmapper not configured")
+			}
+
+			if config.RootPath == "" {
+				config.RootPath = ic.Root
+			}
+
+			return devmapper.NewSnapshotter(ic.Context, config)
+		},
+	})
+}

snapshots/devmapper/snapshotter.go

@@ -30,8 +30,6 @@ import (
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/log"
 	"github.com/containerd/containerd/mount"
-	"github.com/containerd/containerd/platforms"
-	"github.com/containerd/containerd/plugin"
 	"github.com/containerd/containerd/snapshots"
 	"github.com/containerd/containerd/snapshots/devmapper/dmsetup"
 	"github.com/containerd/containerd/snapshots/storage"
@@ -40,32 +38,6 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
-func init() {
-	plugin.Register(&plugin.Registration{
-		Type:   plugin.SnapshotPlugin,
-		ID:     "devmapper",
-		Config: &Config{},
-		InitFn: func(ic *plugin.InitContext) (interface{}, error) {
-			ic.Meta.Platforms = append(ic.Meta.Platforms, platforms.DefaultSpec())
-
-			config, ok := ic.Config.(*Config)
-			if !ok {
-				return nil, errors.New("invalid devmapper configuration")
-			}
-
-			if config.PoolName == "" {
-				return nil, errors.New("devmapper not configured")
-			}
-
-			if config.RootPath == "" {
-				config.RootPath = ic.Root
-			}
-
-			return NewSnapshotter(ic.Context, config)
-		},
-	})
-}
-
 const (
 	metadataFileName = "metadata.db"
 	fsTypeExt4       = "ext4"