From 8ff99bf3122429fa3c44e702e8d1c92866d02867 Mon Sep 17 00:00:00 2001
From: Allen Sun <allensun.shl@alibaba-inc.com>
Date: Thu, 10 May 2018 16:24:44 +0800
Subject: [PATCH] refactor: reorder function sequence to make it more
 reasonable

Signed-off-by: Allen Sun <allensun.shl@alibaba-inc.com>
---
 apis/server/container_bridge.go | 336 +++++++++++---------------
 apis/server/exec_bridge.go      |  83 +++++++
 apis/server/image_bridge.go     |  22 +-
 apis/server/network_bridge.go   |  26 +-
 apis/server/volume_bridge.go    |  20 +-
 daemon/mgr/container.go         | 404 ++++++++++++--------------------
 daemon/mgr/container_exec.go    | 131 +++++++++++
 daemon/mgr/image.go             | 154 ++++++------
 daemon/mgr/network.go           | 142 +++++------
 daemon/mgr/volume.go            |  54 ++---
 10 files changed, 706 insertions(+), 666 deletions(-)
 create mode 100644 apis/server/exec_bridge.go
 create mode 100644 daemon/mgr/container_exec.go

diff --git a/apis/server/container_bridge.go b/apis/server/container_bridge.go
index 067520dbe..9386591dc 100644
--- a/apis/server/container_bridge.go
+++ b/apis/server/container_bridge.go
@@ -20,169 +20,155 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
-func (s *Server) removeContainers(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
-	name := mux.Vars(req)["name"]
-
-	option := &types.ContainerRemoveOptions{
-		Force:   httputils.BoolValue(req, "force"),
-		Volumes: httputils.BoolValue(req, "v"),
-		// TODO: Link will be supported in the future.
-		Link: httputils.BoolValue(req, "link"),
+func (s *Server) createContainer(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
+	config := &types.ContainerCreateConfig{}
+	reader := req.Body
+	var ex error
+	if s.ContainerPlugin != nil {
+		logrus.Infof("invoke container pre-create hook in plugin")
+		if reader, ex = s.ContainerPlugin.PreCreate(req.Body); ex != nil {
+			return errors.Wrapf(ex, "pre-create plugin point execute failed")
+		}
 	}
-
-	if err := s.ContainerMgr.Remove(ctx, name, option); err != nil {
-		return err
+	// decode request body
+	if err := json.NewDecoder(reader).Decode(config); err != nil {
+		return httputils.NewHTTPError(err, http.StatusBadRequest)
+	}
+	// validate request body
+	if err := config.Validate(strfmt.NewFormats()); err != nil {
+		return httputils.NewHTTPError(err, http.StatusBadRequest)
 	}
 
-	rw.WriteHeader(http.StatusNoContent)
-	return nil
-}
+	name := req.FormValue("name")
 
-func (s *Server) renameContainer(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
-	oldName := mux.Vars(req)["name"]
-	newName := req.FormValue("name")
+	// to do compensation to potential nil pointer after validation
+	if config.HostConfig == nil {
+		config.HostConfig = &types.HostConfig{}
+	}
+	if config.NetworkingConfig == nil {
+		config.NetworkingConfig = &types.NetworkingConfig{}
+	}
 
-	if err := s.ContainerMgr.Rename(ctx, oldName, newName); err != nil {
+	container, err := s.ContainerMgr.Create(ctx, name, config)
+	if err != nil {
 		return err
 	}
 
-	rw.WriteHeader(http.StatusNoContent)
-	return nil
+	return EncodeResponse(rw, http.StatusCreated, container)
 }
 
-func (s *Server) restartContainer(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
-	var (
-		t   int
-		err error
-	)
-
-	if v := req.FormValue("t"); v != "" {
-		if t, err = strconv.Atoi(v); err != nil {
-			return httputils.NewHTTPError(err, http.StatusBadRequest)
-		}
-	}
-
+func (s *Server) getContainer(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
 	name := mux.Vars(req)["name"]
 
-	if err = s.ContainerMgr.Restart(ctx, name, int64(t)); err != nil {
+	meta, err := s.ContainerMgr.Get(ctx, name)
+	if err != nil {
 		return err
 	}
 
-	rw.WriteHeader(http.StatusNoContent)
-	return nil
-}
-
-func (s *Server) createContainerExec(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
-	config := &types.ExecCreateConfig{}
-	// decode request body
-	if err := json.NewDecoder(req.Body).Decode(config); err != nil {
-		return httputils.NewHTTPError(err, http.StatusBadRequest)
-	}
-	// validate request body
-	if err := config.Validate(strfmt.NewFormats()); err != nil {
-		return httputils.NewHTTPError(err, http.StatusBadRequest)
+	container := types.ContainerJSON{
+		ID:          meta.ID,
+		Name:        meta.Name,
+		Image:       meta.Config.Image,
+		Created:     meta.Created,
+		State:       meta.State,
+		Config:      meta.Config,
+		HostConfig:  meta.HostConfig,
+		Snapshotter: meta.Snapshotter,
+		GraphDriver: &types.GraphDriverData{
+			Name: meta.Snapshotter.Name,
+			Data: meta.Snapshotter.Data,
+		},
 	}
 
-	name := mux.Vars(req)["name"]
-
-	id, err := s.ContainerMgr.CreateExec(ctx, name, config)
-	if err != nil {
-		return err
+	if meta.NetworkSettings != nil {
+		container.NetworkSettings = &types.NetworkSettings{
+			Networks: meta.NetworkSettings.Networks,
+		}
 	}
 
-	execCreateResp := &types.ExecCreateResp{
-		ID: id,
+	container.Mounts = []types.MountPoint{}
+	for _, mp := range meta.Mounts {
+		container.Mounts = append(container.Mounts, *mp)
 	}
 
-	return EncodeResponse(rw, http.StatusCreated, execCreateResp)
+	return EncodeResponse(rw, http.StatusOK, container)
 }
 
-func (s *Server) startContainerExec(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
-	config := &types.ExecStartConfig{}
-	// decode request body
-	if err := json.NewDecoder(req.Body).Decode(config); err != nil {
-		return httputils.NewHTTPError(err, http.StatusBadRequest)
+func (s *Server) getContainers(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
+	option := &mgr.ContainerListOption{
+		All: httputils.BoolValue(req, "all"),
 	}
-	// validate request body
-	if err := config.Validate(strfmt.NewFormats()); err != nil {
-		return httputils.NewHTTPError(err, http.StatusBadRequest)
+
+	metas, err := s.ContainerMgr.List(ctx, func(meta *mgr.ContainerMeta) bool {
+		return true
+	}, option)
+	if err != nil {
+		return err
 	}
 
-	name := mux.Vars(req)["name"]
-	_, upgrade := req.Header["Upgrade"]
+	containerList := make([]types.Container, 0, len(metas))
 
-	var attach *mgr.AttachConfig
+	for _, m := range metas {
+		status, err := m.FormatStatus()
+		if err != nil {
+			return err
+		}
 
-	if !config.Detach {
-		hijacker, ok := rw.(http.Hijacker)
-		if !ok {
-			return fmt.Errorf("not a hijack connection, container: %s", name)
+		t, err := time.Parse(utils.TimeLayout, m.Created)
+		if err != nil {
+			return err
 		}
 
-		attach = &mgr.AttachConfig{
-			Hijack:  hijacker,
-			Stdin:   config.Tty,
-			Stdout:  true,
-			Stderr:  true,
-			Upgrade: upgrade,
+		container := types.Container{
+			ID:         m.ID,
+			Names:      []string{m.Name},
+			Image:      m.Config.Image,
+			Command:    strings.Join(m.Config.Cmd, " "),
+			Status:     status,
+			Created:    t.UnixNano(),
+			Labels:     m.Config.Labels,
+			HostConfig: m.HostConfig,
 		}
-	}
 
-	return s.ContainerMgr.StartExec(ctx, name, config, attach)
-}
+		if m.NetworkSettings != nil {
+			container.NetworkSettings = &types.ContainerNetworkSettings{
+				Networks: m.NetworkSettings.Networks,
+			}
+		}
 
-func (s *Server) getExecInfo(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
-	name := mux.Vars(req)["name"]
-	execInfo, err := s.ContainerMgr.InspectExec(ctx, name)
-	if err != nil {
-		return err
+		containerList = append(containerList, container)
 	}
-	return EncodeResponse(rw, http.StatusOK, execInfo)
+	return EncodeResponse(rw, http.StatusOK, containerList)
 }
 
-func (s *Server) createContainer(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
-	config := &types.ContainerCreateConfig{}
-	reader := req.Body
-	var ex error
-	if s.ContainerPlugin != nil {
-		logrus.Infof("invoke container pre-create hook in plugin")
-		if reader, ex = s.ContainerPlugin.PreCreate(req.Body); ex != nil {
-			return errors.Wrapf(ex, "pre-create plugin point execute failed")
-		}
-	}
-	// decode request body
-	if err := json.NewDecoder(reader).Decode(config); err != nil {
-		return httputils.NewHTTPError(err, http.StatusBadRequest)
-	}
-	// validate request body
-	if err := config.Validate(strfmt.NewFormats()); err != nil {
-		return httputils.NewHTTPError(err, http.StatusBadRequest)
-	}
-
-	name := req.FormValue("name")
+func (s *Server) startContainer(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
+	name := mux.Vars(req)["name"]
 
-	// to do compensation to potential nil pointer after validation
-	if config.HostConfig == nil {
-		config.HostConfig = &types.HostConfig{}
-	}
-	if config.NetworkingConfig == nil {
-		config.NetworkingConfig = &types.NetworkingConfig{}
-	}
+	detachKeys := req.FormValue("detachKeys")
 
-	container, err := s.ContainerMgr.Create(ctx, name, config)
-	if err != nil {
+	if err := s.ContainerMgr.Start(ctx, name, detachKeys); err != nil {
 		return err
 	}
 
-	return EncodeResponse(rw, http.StatusCreated, container)
+	rw.WriteHeader(http.StatusNoContent)
+	return nil
 }
 
-func (s *Server) startContainer(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
-	name := mux.Vars(req)["name"]
+func (s *Server) restartContainer(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
+	var (
+		t   int
+		err error
+	)
 
-	detachKeys := req.FormValue("detachKeys")
+	if v := req.FormValue("t"); v != "" {
+		if t, err = strconv.Atoi(v); err != nil {
+			return httputils.NewHTTPError(err, http.StatusBadRequest)
+		}
+	}
 
-	if err := s.ContainerMgr.Start(ctx, name, detachKeys); err != nil {
+	name := mux.Vars(req)["name"]
+
+	if err = s.ContainerMgr.Restart(ctx, name, int64(t)); err != nil {
 		return err
 	}
 
@@ -234,6 +220,18 @@ func (s *Server) unpauseContainer(ctx context.Context, rw http.ResponseWriter, r
 	return nil
 }
 
+func (s *Server) renameContainer(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
+	oldName := mux.Vars(req)["name"]
+	newName := req.FormValue("name")
+
+	if err := s.ContainerMgr.Rename(ctx, oldName, newName); err != nil {
+		return err
+	}
+
+	rw.WriteHeader(http.StatusNoContent)
+	return nil
+}
+
 func (s *Server) attachContainer(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
 	name := mux.Vars(req)["name"]
 
@@ -259,90 +257,6 @@ func (s *Server) attachContainer(ctx context.Context, rw http.ResponseWriter, re
 	return nil
 }
 
-func (s *Server) getContainers(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
-	option := &mgr.ContainerListOption{
-		All: httputils.BoolValue(req, "all"),
-	}
-
-	metas, err := s.ContainerMgr.List(ctx, func(meta *mgr.ContainerMeta) bool {
-		return true
-	}, option)
-	if err != nil {
-		return err
-	}
-
-	containerList := make([]types.Container, 0, len(metas))
-
-	for _, m := range metas {
-		status, err := m.FormatStatus()
-		if err != nil {
-			return err
-		}
-
-		t, err := time.Parse(utils.TimeLayout, m.Created)
-		if err != nil {
-			return err
-		}
-
-		container := types.Container{
-			ID:         m.ID,
-			Names:      []string{m.Name},
-			Image:      m.Config.Image,
-			Command:    strings.Join(m.Config.Cmd, " "),
-			Status:     status,
-			Created:    t.UnixNano(),
-			Labels:     m.Config.Labels,
-			HostConfig: m.HostConfig,
-		}
-
-		if m.NetworkSettings != nil {
-			container.NetworkSettings = &types.ContainerNetworkSettings{
-				Networks: m.NetworkSettings.Networks,
-			}
-		}
-
-		containerList = append(containerList, container)
-	}
-	return EncodeResponse(rw, http.StatusOK, containerList)
-}
-
-func (s *Server) getContainer(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
-	name := mux.Vars(req)["name"]
-
-	meta, err := s.ContainerMgr.Get(ctx, name)
-	if err != nil {
-		return err
-	}
-
-	container := types.ContainerJSON{
-		ID:          meta.ID,
-		Name:        meta.Name,
-		Image:       meta.Config.Image,
-		Created:     meta.Created,
-		State:       meta.State,
-		Config:      meta.Config,
-		HostConfig:  meta.HostConfig,
-		Snapshotter: meta.Snapshotter,
-		GraphDriver: &types.GraphDriverData{
-			Name: meta.Snapshotter.Name,
-			Data: meta.Snapshotter.Data,
-		},
-	}
-
-	if meta.NetworkSettings != nil {
-		container.NetworkSettings = &types.NetworkSettings{
-			Networks: meta.NetworkSettings.Networks,
-		}
-	}
-
-	container.Mounts = []types.MountPoint{}
-	for _, mp := range meta.Mounts {
-		container.Mounts = append(container.Mounts, *mp)
-	}
-
-	return EncodeResponse(rw, http.StatusOK, container)
-}
-
 func (s *Server) updateContainer(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
 	config := &types.UpdateConfig{}
 	// decode request body
@@ -428,3 +342,21 @@ func (s *Server) resizeContainer(ctx context.Context, rw http.ResponseWriter, re
 	rw.WriteHeader(http.StatusOK)
 	return nil
 }
+
+func (s *Server) removeContainers(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
+	name := mux.Vars(req)["name"]
+
+	option := &types.ContainerRemoveOptions{
+		Force:   httputils.BoolValue(req, "force"),
+		Volumes: httputils.BoolValue(req, "v"),
+		// TODO: Link will be supported in the future.
+		Link: httputils.BoolValue(req, "link"),
+	}
+
+	if err := s.ContainerMgr.Remove(ctx, name, option); err != nil {
+		return err
+	}
+
+	rw.WriteHeader(http.StatusNoContent)
+	return nil
+}
diff --git a/apis/server/exec_bridge.go b/apis/server/exec_bridge.go
new file mode 100644
index 000000000..87f418fa5
--- /dev/null
+++ b/apis/server/exec_bridge.go
@@ -0,0 +1,83 @@
+package server
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	"github.com/alibaba/pouch/apis/types"
+	"github.com/alibaba/pouch/daemon/mgr"
+	"github.com/alibaba/pouch/pkg/httputils"
+
+	"github.com/go-openapi/strfmt"
+	"github.com/gorilla/mux"
+)
+
+func (s *Server) createContainerExec(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
+	config := &types.ExecCreateConfig{}
+	// decode request body
+	if err := json.NewDecoder(req.Body).Decode(config); err != nil {
+		return httputils.NewHTTPError(err, http.StatusBadRequest)
+	}
+	// validate request body
+	if err := config.Validate(strfmt.NewFormats()); err != nil {
+		return httputils.NewHTTPError(err, http.StatusBadRequest)
+	}
+
+	name := mux.Vars(req)["name"]
+
+	id, err := s.ContainerMgr.CreateExec(ctx, name, config)
+	if err != nil {
+		return err
+	}
+
+	execCreateResp := &types.ExecCreateResp{
+		ID: id,
+	}
+
+	return EncodeResponse(rw, http.StatusCreated, execCreateResp)
+}
+
+func (s *Server) startContainerExec(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
+	config := &types.ExecStartConfig{}
+	// decode request body
+	if err := json.NewDecoder(req.Body).Decode(config); err != nil {
+		return httputils.NewHTTPError(err, http.StatusBadRequest)
+	}
+	// validate request body
+	if err := config.Validate(strfmt.NewFormats()); err != nil {
+		return httputils.NewHTTPError(err, http.StatusBadRequest)
+	}
+
+	name := mux.Vars(req)["name"]
+	_, upgrade := req.Header["Upgrade"]
+
+	var attach *mgr.AttachConfig
+
+	if !config.Detach {
+		hijacker, ok := rw.(http.Hijacker)
+		if !ok {
+			return fmt.Errorf("not a hijack connection, container: %s", name)
+		}
+
+		attach = &mgr.AttachConfig{
+			Hijack:  hijacker,
+			Stdin:   config.Tty,
+			Stdout:  true,
+			Stderr:  true,
+			Upgrade: upgrade,
+		}
+	}
+
+	return s.ContainerMgr.StartExec(ctx, name, config, attach)
+}
+
+func (s *Server) getExecInfo(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
+	name := mux.Vars(req)["name"]
+	execInfo, err := s.ContainerMgr.InspectExec(ctx, name)
+	if err != nil {
+		return err
+	}
+	return EncodeResponse(rw, http.StatusOK, execInfo)
+}
diff --git a/apis/server/image_bridge.go b/apis/server/image_bridge.go
index 8aace658c..b32ee6b72 100644
--- a/apis/server/image_bridge.go
+++ b/apis/server/image_bridge.go
@@ -54,17 +54,6 @@ func (s *Server) pullImage(ctx context.Context, rw http.ResponseWriter, req *htt
 	return nil
 }
 
-func (s *Server) listImages(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
-	filters := req.FormValue("filters")
-
-	imageList, err := s.ImageMgr.ListImages(ctx, filters)
-	if err != nil {
-		logrus.Errorf("failed to list images: %v", err)
-		return err
-	}
-	return EncodeResponse(rw, http.StatusOK, imageList)
-}
-
 func (s *Server) getImage(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
 	idOrRef := mux.Vars(req)["name"]
 
@@ -77,6 +66,17 @@ func (s *Server) getImage(ctx context.Context, rw http.ResponseWriter, req *http
 	return EncodeResponse(rw, http.StatusOK, imageInfo)
 }
 
+func (s *Server) listImages(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
+	filters := req.FormValue("filters")
+
+	imageList, err := s.ImageMgr.ListImages(ctx, filters)
+	if err != nil {
+		logrus.Errorf("failed to list images: %v", err)
+		return err
+	}
+	return EncodeResponse(rw, http.StatusOK, imageList)
+}
+
 func (s *Server) searchImages(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
 	searchPattern := req.FormValue("term")
 	registry := req.FormValue("registry")
diff --git a/apis/server/network_bridge.go b/apis/server/network_bridge.go
index d9352e408..9cd211a84 100644
--- a/apis/server/network_bridge.go
+++ b/apis/server/network_bridge.go
@@ -37,6 +37,19 @@ func (s *Server) createNetwork(ctx context.Context, rw http.ResponseWriter, req
 	return EncodeResponse(rw, http.StatusCreated, networkCreateResp)
 }
 
+func (s *Server) getNetwork(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
+	id := mux.Vars(req)["id"]
+
+	network, err := s.NetworkMgr.Get(ctx, id)
+	if err != nil {
+		return err
+	}
+
+	networkResp := buildNetworkInspectResp(network)
+
+	return EncodeResponse(rw, http.StatusOK, networkResp)
+}
+
 func (s *Server) listNetwork(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
 	networks, err := s.NetworkMgr.List(ctx, map[string]string{})
 	if err != nil {
@@ -54,19 +67,6 @@ func (s *Server) listNetwork(ctx context.Context, rw http.ResponseWriter, req *h
 	return EncodeResponse(rw, http.StatusOK, respNetworks)
 }
 
-func (s *Server) getNetwork(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
-	id := mux.Vars(req)["id"]
-
-	network, err := s.NetworkMgr.Get(ctx, id)
-	if err != nil {
-		return err
-	}
-
-	networkResp := buildNetworkInspectResp(network)
-
-	return EncodeResponse(rw, http.StatusOK, networkResp)
-}
-
 func (s *Server) deleteNetwork(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
 	id := mux.Vars(req)["id"]
 
diff --git a/apis/server/volume_bridge.go b/apis/server/volume_bridge.go
index cf86cc1a0..16b17f133 100644
--- a/apis/server/volume_bridge.go
+++ b/apis/server/volume_bridge.go
@@ -97,16 +97,6 @@ func (s *Server) getVolume(ctx context.Context, rw http.ResponseWriter, req *htt
 	return EncodeResponse(rw, http.StatusOK, respVolume)
 }
 
-func (s *Server) removeVolume(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
-	name := mux.Vars(req)["name"]
-
-	if err := s.VolumeMgr.Remove(ctx, name); err != nil {
-		return err
-	}
-	rw.WriteHeader(http.StatusNoContent)
-	return nil
-}
-
 func (s *Server) listVolume(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
 	volumes, err := s.VolumeMgr.List(ctx, map[string]string{})
 	if err != nil {
@@ -138,3 +128,13 @@ func (s *Server) listVolume(ctx context.Context, rw http.ResponseWriter, req *ht
 	}
 	return EncodeResponse(rw, http.StatusOK, respVolumes)
 }
+
+func (s *Server) removeVolume(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
+	name := mux.Vars(req)["name"]
+
+	if err := s.VolumeMgr.Remove(ctx, name); err != nil {
+		return err
+	}
+	rw.WriteHeader(http.StatusNoContent)
+	return nil
+}
diff --git a/daemon/mgr/container.go b/daemon/mgr/container.go
index c7fe50843..4235b2616 100644
--- a/daemon/mgr/container.go
+++ b/daemon/mgr/container.go
@@ -37,22 +37,36 @@ import (
 	"github.com/magiconair/properties"
 	digest "github.com/opencontainers/go-digest"
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
-	"github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
 
 // ContainerMgr as an interface defines all operations against container.
+// ContainerMgr's functionality could be divided into three parts:
+// 1. regular container management;
+// 2. container exec management;
+// 3. container network management.
 type ContainerMgr interface {
+	// 1. the following functions are related to regular container management
+
 	// Create a new container.
 	Create(ctx context.Context, name string, config *types.ContainerCreateConfig) (*types.ContainerCreateResp, error)
 
+	// Get the detailed information of container.
+	Get(ctx context.Context, name string) (*ContainerMeta, error)
+
+	// List returns the list of containers.
+	List(ctx context.Context, filter ContainerFilter, option *ContainerListOption) ([]*ContainerMeta, error)
+
 	// Start a container.
 	Start(ctx context.Context, id, detachKeys string) error
 
 	// Stop a container.
 	Stop(ctx context.Context, name string, timeout int64) error
 
+	// Restart restart a running container.
+	Restart(ctx context.Context, name string, timeout int64) error
+
 	// Pause a container.
 	Pause(ctx context.Context, name string) error
 
@@ -62,30 +76,9 @@ type ContainerMgr interface {
 	// Attach a container.
 	Attach(ctx context.Context, name string, attach *AttachConfig) error
 
-	// List returns the list of containers.
-	List(ctx context.Context, filter ContainerFilter, option *ContainerListOption) ([]*ContainerMeta, error)
-
-	// CreateExec creates exec process's environment.
-	CreateExec(ctx context.Context, name string, config *types.ExecCreateConfig) (string, error)
-
-	// StartExec executes a new process in container.
-	StartExec(ctx context.Context, execid string, config *types.ExecStartConfig, attach *AttachConfig) error
-
-	// InspectExec returns low-level information about exec command.
-	InspectExec(ctx context.Context, execid string) (*types.ContainerExecInspect, error)
-
-	// GetExecConfig returns execonfig of a exec process inside container.
-	GetExecConfig(ctx context.Context, execid string) (*ContainerExecConfig, error)
-
-	// Remove removes a container, it may be running or stopped and so on.
-	Remove(ctx context.Context, name string, option *types.ContainerRemoveOptions) error
-
 	// Rename renames a container.
 	Rename(ctx context.Context, oldName string, newName string) error
 
-	// Get the detailed information of container.
-	Get(ctx context.Context, name string) (*ContainerMeta, error)
-
 	// Update updates the configurations of a container.
 	Update(ctx context.Context, name string, config *types.UpdateConfig) error
 
@@ -98,8 +91,26 @@ type ContainerMgr interface {
 	// Resize resizes the size of container tty.
 	Resize(ctx context.Context, name string, opts types.ResizeOptions) error
 
-	// Restart restart a running container.
-	Restart(ctx context.Context, name string, timeout int64) error
+	// Remove removes a container, it may be running or stopped and so on.
+	Remove(ctx context.Context, name string, option *types.ContainerRemoveOptions) error
+
+	// 2. The following five functions is related to containr exec.
+
+	// CreateExec creates exec process's environment.
+	CreateExec(ctx context.Context, name string, config *types.ExecCreateConfig) (string, error)
+
+	// StartExec executes a new process in container.
+	StartExec(ctx context.Context, execid string, config *types.ExecStartConfig, attach *AttachConfig) error
+
+	// InspectExec returns low-level information about exec command.
+	InspectExec(ctx context.Context, execid string) (*types.ContainerExecInspect, error)
+
+	// GetExecConfig returns execonfig of a exec process inside container.
+	GetExecConfig(ctx context.Context, execid string) (*ContainerExecConfig, error)
+
+	// 3. The following two function is related to network management.
+	// TODO: inconsistency, Connect/Disconnect operation is in newtork_bridge.go in upper API layer.
+	// Here we encapsualted them in container manager, inconsistency exists.
 
 	// Connect is used to connect a container to a network.
 	Connect(ctx context.Context, name string, networkIDOrName string, epConfig *types.EndpointSettings) error
@@ -210,170 +221,6 @@ func (mgr *ContainerManager) Restore(ctx context.Context) error {
 	return mgr.Store.ForEach(fn)
 }
 
-// Remove removes a container, it may be running or stopped and so on.
-func (mgr *ContainerManager) Remove(ctx context.Context, name string, options *types.ContainerRemoveOptions) error {
-	c, err := mgr.container(name)
-	if err != nil {
-		return err
-	}
-	c.Lock()
-	defer c.Unlock()
-
-	if !c.IsStopped() && !c.IsExited() && !c.IsCreated() && !options.Force {
-		return fmt.Errorf("container: %s is not stopped, can't remove it without flag force", c.ID())
-	}
-
-	// if the container is running, force to stop it.
-	if c.IsRunning() && options.Force {
-		msg, err := mgr.Client.DestroyContainer(ctx, c.ID(), c.StopTimeout())
-		if err != nil && !errtypes.IsNotfound(err) {
-			return errors.Wrapf(err, "failed to destroy container: %s", c.ID())
-		}
-		if err := mgr.markStoppedAndRelease(c, msg); err != nil {
-			return errors.Wrapf(err, "failed to mark container: %s stop status", c.ID())
-		}
-	}
-
-	if err := mgr.detachVolumes(ctx, c.meta, options.Volumes); err != nil {
-		logrus.Errorf("failed to detach volume: %v", err)
-	}
-
-	// remove name
-	mgr.NameToID.Remove(c.Name())
-
-	// remove meta data
-	if err := mgr.Store.Remove(c.meta.Key()); err != nil {
-		logrus.Errorf("failed to remove container: %s meta store, %v", c.ID(), err)
-	}
-
-	// remove container cache
-	mgr.cache.Remove(c.ID())
-
-	// remove snapshot
-	if err := mgr.Client.RemoveSnapshot(ctx, c.ID()); err != nil {
-		logrus.Errorf("failed to remove container: %s snapshot, %v", c.ID(), err)
-	}
-
-	return nil
-}
-
-// CreateExec creates exec process's meta data.
-func (mgr *ContainerManager) CreateExec(ctx context.Context, name string, config *types.ExecCreateConfig) (string, error) {
-	c, err := mgr.container(name)
-	if err != nil {
-		return "", err
-	}
-
-	if !c.IsRunning() {
-		return "", fmt.Errorf("container %s is not running", c.ID())
-	}
-
-	execid := randomid.Generate()
-	execConfig := &ContainerExecConfig{
-		ExecID:           execid,
-		ExecCreateConfig: *config,
-		ContainerID:      c.ID(),
-	}
-
-	mgr.ExecProcesses.Put(execid, execConfig)
-
-	return execid, nil
-}
-
-// StartExec executes a new process in container.
-func (mgr *ContainerManager) StartExec(ctx context.Context, execid string, config *types.ExecStartConfig, attach *AttachConfig) error {
-	v, ok := mgr.ExecProcesses.Get(execid).Result()
-	if !ok {
-		return errors.Wrap(errtypes.ErrNotfound, "to be exec process: "+execid)
-	}
-	execConfig, ok := v.(*ContainerExecConfig)
-	if !ok {
-		return fmt.Errorf("invalid exec config type")
-	}
-
-	if attach != nil {
-		attach.Stdin = execConfig.AttachStdin
-	}
-
-	io, err := mgr.openExecIO(execid, attach)
-	if err != nil {
-		return err
-	}
-
-	c, err := mgr.container(execConfig.ContainerID)
-	if err != nil {
-		return err
-	}
-
-	process := &specs.Process{
-		Args:     execConfig.Cmd,
-		Terminal: execConfig.Tty,
-		Cwd:      "/",
-		Env:      c.Config().Env,
-	}
-
-	if execConfig.User != "" {
-		c.meta.Config.User = execConfig.User
-	}
-
-	if err = setupUser(ctx, c.meta, &specs.Spec{Process: process}); err != nil {
-		return err
-	}
-
-	// set exec process ulimit
-	if err := setupRlimits(ctx, c.meta.HostConfig, &specs.Spec{Process: process}); err != nil {
-		return err
-	}
-
-	execConfig.Running = true
-	defer func() {
-		if err != nil {
-			execConfig.Running = false
-			exitCode := 126
-			execConfig.ExitCode = int64(exitCode)
-		}
-		mgr.ExecProcesses.Put(execid, execConfig)
-	}()
-
-	err = mgr.Client.ExecContainer(ctx, &ctrd.Process{
-		ContainerID: execConfig.ContainerID,
-		ExecID:      execid,
-		IO:          io,
-		P:           process,
-	})
-
-	return err
-}
-
-// InspectExec returns low-level information about exec command.
-func (mgr *ContainerManager) InspectExec(ctx context.Context, execid string) (*types.ContainerExecInspect, error) {
-	execConfig, err := mgr.GetExecConfig(ctx, execid)
-	if err != nil {
-		return nil, err
-	}
-
-	return &types.ContainerExecInspect{
-		ID: execConfig.ExecID,
-		// FIXME: try to use the correct running status of exec
-		Running:     execConfig.Running,
-		ExitCode:    execConfig.ExitCode,
-		ContainerID: execConfig.ContainerID,
-	}, nil
-}
-
-// GetExecConfig returns execonfig of a exec process inside container.
-func (mgr *ContainerManager) GetExecConfig(ctx context.Context, execid string) (*ContainerExecConfig, error) {
-	v, ok := mgr.ExecProcesses.Get(execid).Result()
-	if !ok {
-		return nil, errors.Wrap(errtypes.ErrNotfound, "exec process "+execid)
-	}
-	execConfig, ok := v.(*ContainerExecConfig)
-	if !ok {
-		return nil, fmt.Errorf("invalid exec config type")
-	}
-	return execConfig, nil
-}
-
 // Create checks passed in parameters and create a Container object whose status is set at Created.
 func (mgr *ContainerManager) Create(ctx context.Context, name string, config *types.ContainerCreateConfig) (*types.ContainerCreateResp, error) {
 	imgID, _, primaryRef, err := mgr.ImageMgr.CheckReference(ctx, config.Image)
@@ -528,6 +375,45 @@ func (mgr *ContainerManager) Create(ctx context.Context, name string, config *ty
 	}, nil
 }
 
+// Get the detailed information of container.
+func (mgr *ContainerManager) Get(ctx context.Context, name string) (*ContainerMeta, error) {
+	c, err := mgr.container(name)
+	if err != nil {
+		return nil, err
+	}
+
+	c.Lock()
+	defer c.Unlock()
+
+	return c.meta, nil
+}
+
+// List returns the container's list.
+func (mgr *ContainerManager) List(ctx context.Context, filter ContainerFilter, option *ContainerListOption) ([]*ContainerMeta, error) {
+	metas := []*ContainerMeta{}
+
+	list, err := mgr.Store.List()
+	if err != nil {
+		return nil, err
+	}
+
+	for _, obj := range list {
+		m, ok := obj.(*ContainerMeta)
+		if !ok {
+			return nil, fmt.Errorf("failed to get container list, invalid meta type")
+		}
+		if filter != nil && filter(m) {
+			if option.All {
+				metas = append(metas, m)
+			} else if m.State.Status == types.StatusRunning || m.State.Status == types.StatusPaused {
+				metas = append(metas, m)
+			}
+		}
+	}
+
+	return metas, nil
+}
+
 // Start a pre created Container.
 func (mgr *ContainerManager) Start(ctx context.Context, id, detachKeys string) (err error) {
 	if id == "" {
@@ -694,6 +580,33 @@ func (mgr *ContainerManager) stop(ctx context.Context, c *Container, timeout int
 	return mgr.markStoppedAndRelease(c, msg)
 }
 
+// Restart restarts a running container.
+func (mgr *ContainerManager) Restart(ctx context.Context, name string, timeout int64) error {
+	c, err := mgr.container(name)
+	if err != nil {
+		return err
+	}
+
+	c.Lock()
+	defer c.Unlock()
+
+	if timeout == 0 {
+		timeout = c.StopTimeout()
+	}
+
+	if c.IsRunning() || c.IsPaused() {
+		// stop container if it is running or paused.
+		if err := mgr.stop(ctx, c, timeout); err != nil {
+			logrus.Errorf("failed to stop container %s when restarting: %v", c.ID(), err)
+			return errors.Wrapf(err, fmt.Sprintf("failed to stop container %s", c.ID()))
+		}
+	}
+
+	logrus.Debugf("start container %s when restarting", c.ID())
+	// start container
+	return mgr.start(ctx, c, "")
+}
+
 // Pause pauses a running container.
 func (mgr *ContainerManager) Pause(ctx context.Context, name string) error {
 	var (
@@ -781,46 +694,7 @@ func (mgr *ContainerManager) Attach(ctx context.Context, name string, attach *At
 	return nil
 }
 
-// List returns the container's list.
-func (mgr *ContainerManager) List(ctx context.Context, filter ContainerFilter, option *ContainerListOption) ([]*ContainerMeta, error) {
-	metas := []*ContainerMeta{}
-
-	list, err := mgr.Store.List()
-	if err != nil {
-		return nil, err
-	}
-
-	for _, obj := range list {
-		m, ok := obj.(*ContainerMeta)
-		if !ok {
-			return nil, fmt.Errorf("failed to get container list, invalid meta type")
-		}
-		if filter != nil && filter(m) {
-			if option.All {
-				metas = append(metas, m)
-			} else if m.State.Status == types.StatusRunning || m.State.Status == types.StatusPaused {
-				metas = append(metas, m)
-			}
-		}
-	}
-
-	return metas, nil
-}
-
-// Get the detailed information of container.
-func (mgr *ContainerManager) Get(ctx context.Context, name string) (*ContainerMeta, error) {
-	c, err := mgr.container(name)
-	if err != nil {
-		return nil, err
-	}
-
-	c.Lock()
-	defer c.Unlock()
-
-	return c.meta, nil
-}
-
-// Rename renames a container
+// Rename renames a container.
 func (mgr *ContainerManager) Rename(ctx context.Context, oldName, newName string) error {
 	var (
 		c   *Container
@@ -941,6 +815,53 @@ func (mgr *ContainerManager) Update(ctx context.Context, name string, config *ty
 	return updateErr
 }
 
+// Remove removes a container, it may be running or stopped and so on.
+func (mgr *ContainerManager) Remove(ctx context.Context, name string, options *types.ContainerRemoveOptions) error {
+	c, err := mgr.container(name)
+	if err != nil {
+		return err
+	}
+	c.Lock()
+	defer c.Unlock()
+
+	if !c.IsStopped() && !c.IsExited() && !c.IsCreated() && !options.Force {
+		return fmt.Errorf("container: %s is not stopped, can't remove it without flag force", c.ID())
+	}
+
+	// if the container is running, force to stop it.
+	if c.IsRunning() && options.Force {
+		msg, err := mgr.Client.DestroyContainer(ctx, c.ID(), c.StopTimeout())
+		if err != nil && !errtypes.IsNotfound(err) {
+			return errors.Wrapf(err, "failed to destroy container: %s", c.ID())
+		}
+		if err := mgr.markStoppedAndRelease(c, msg); err != nil {
+			return errors.Wrapf(err, "failed to mark container: %s stop status", c.ID())
+		}
+	}
+
+	if err := mgr.detachVolumes(ctx, c.meta, options.Volumes); err != nil {
+		logrus.Errorf("failed to detach volume: %v", err)
+	}
+
+	// remove name
+	mgr.NameToID.Remove(c.Name())
+
+	// remove meta data
+	if err := mgr.Store.Remove(c.meta.Key()); err != nil {
+		logrus.Errorf("failed to remove container: %s meta store, %v", c.ID(), err)
+	}
+
+	// remove container cache
+	mgr.cache.Remove(c.ID())
+
+	// remove snapshot
+	if err := mgr.Client.RemoveSnapshot(ctx, c.ID()); err != nil {
+		logrus.Errorf("failed to remove container: %s snapshot, %v", c.ID(), err)
+	}
+
+	return nil
+}
+
 func (mgr *ContainerManager) updateContainerDiskQuota(ctx context.Context, c *ContainerMeta, diskQuota string) error {
 	if diskQuota == "" {
 		return nil
@@ -1340,33 +1261,6 @@ func (mgr *ContainerManager) Resize(ctx context.Context, name string, opts types
 	return mgr.Client.ResizeContainer(ctx, c.ID(), opts)
 }
 
-// Restart restarts a running container.
-func (mgr *ContainerManager) Restart(ctx context.Context, name string, timeout int64) error {
-	c, err := mgr.container(name)
-	if err != nil {
-		return err
-	}
-
-	c.Lock()
-	defer c.Unlock()
-
-	if timeout == 0 {
-		timeout = c.StopTimeout()
-	}
-
-	if c.IsRunning() || c.IsPaused() {
-		// stop container if it is running or paused.
-		if err := mgr.stop(ctx, c, timeout); err != nil {
-			logrus.Errorf("failed to stop container %s when restarting: %v", c.ID(), err)
-			return errors.Wrapf(err, fmt.Sprintf("failed to stop container %s", c.ID()))
-		}
-	}
-
-	logrus.Debugf("start container %s when restarting", c.ID())
-	// start container
-	return mgr.start(ctx, c, "")
-}
-
 // Connect is used to connect a container to a network.
 func (mgr *ContainerManager) Connect(ctx context.Context, name string, networkIDOrName string, epConfig *types.EndpointSettings) error {
 	c, err := mgr.container(name)
diff --git a/daemon/mgr/container_exec.go b/daemon/mgr/container_exec.go
new file mode 100644
index 000000000..4cf9aeaab
--- /dev/null
+++ b/daemon/mgr/container_exec.go
@@ -0,0 +1,131 @@
+package mgr
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/alibaba/pouch/apis/types"
+	"github.com/alibaba/pouch/ctrd"
+	"github.com/alibaba/pouch/pkg/errtypes"
+	"github.com/alibaba/pouch/pkg/randomid"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/pkg/errors"
+)
+
+// CreateExec creates exec process's meta data.
+func (mgr *ContainerManager) CreateExec(ctx context.Context, name string, config *types.ExecCreateConfig) (string, error) {
+	c, err := mgr.container(name)
+	if err != nil {
+		return "", err
+	}
+
+	if !c.IsRunning() {
+		return "", fmt.Errorf("container %s is not running", c.ID())
+	}
+
+	execid := randomid.Generate()
+	execConfig := &ContainerExecConfig{
+		ExecID:           execid,
+		ExecCreateConfig: *config,
+		ContainerID:      c.ID(),
+	}
+
+	mgr.ExecProcesses.Put(execid, execConfig)
+
+	return execid, nil
+}
+
+// StartExec executes a new process in container.
+func (mgr *ContainerManager) StartExec(ctx context.Context, execid string, config *types.ExecStartConfig, attach *AttachConfig) error {
+	v, ok := mgr.ExecProcesses.Get(execid).Result()
+	if !ok {
+		return errors.Wrap(errtypes.ErrNotfound, "to be exec process: "+execid)
+	}
+	execConfig, ok := v.(*ContainerExecConfig)
+	if !ok {
+		return fmt.Errorf("invalid exec config type")
+	}
+
+	if attach != nil {
+		attach.Stdin = execConfig.AttachStdin
+	}
+
+	io, err := mgr.openExecIO(execid, attach)
+	if err != nil {
+		return err
+	}
+
+	c, err := mgr.container(execConfig.ContainerID)
+	if err != nil {
+		return err
+	}
+
+	process := &specs.Process{
+		Args:     execConfig.Cmd,
+		Terminal: execConfig.Tty,
+		Cwd:      "/",
+		Env:      c.Config().Env,
+	}
+
+	if execConfig.User != "" {
+		c.meta.Config.User = execConfig.User
+	}
+
+	if err = setupUser(ctx, c.meta, &specs.Spec{Process: process}); err != nil {
+		return err
+	}
+
+	// set exec process ulimit
+	if err := setupRlimits(ctx, c.meta.HostConfig, &specs.Spec{Process: process}); err != nil {
+		return err
+	}
+
+	execConfig.Running = true
+	defer func() {
+		if err != nil {
+			execConfig.Running = false
+			exitCode := 126
+			execConfig.ExitCode = int64(exitCode)
+		}
+		mgr.ExecProcesses.Put(execid, execConfig)
+	}()
+
+	err = mgr.Client.ExecContainer(ctx, &ctrd.Process{
+		ContainerID: execConfig.ContainerID,
+		ExecID:      execid,
+		IO:          io,
+		P:           process,
+	})
+
+	return err
+}
+
+// InspectExec returns low-level information about exec command.
+func (mgr *ContainerManager) InspectExec(ctx context.Context, execid string) (*types.ContainerExecInspect, error) {
+	execConfig, err := mgr.GetExecConfig(ctx, execid)
+	if err != nil {
+		return nil, err
+	}
+
+	return &types.ContainerExecInspect{
+		ID: execConfig.ExecID,
+		// FIXME: try to use the correct running status of exec
+		Running:     execConfig.Running,
+		ExitCode:    execConfig.ExitCode,
+		ContainerID: execConfig.ContainerID,
+	}, nil
+}
+
+// GetExecConfig returns execonfig of a exec process inside container.
+func (mgr *ContainerManager) GetExecConfig(ctx context.Context, execid string) (*ContainerExecConfig, error) {
+	v, ok := mgr.ExecProcesses.Get(execid).Result()
+	if !ok {
+		return nil, errors.Wrap(errtypes.ErrNotfound, "exec process "+execid)
+	}
+	execConfig, ok := v.(*ContainerExecConfig)
+	if !ok {
+		return nil, fmt.Errorf("invalid exec config type")
+	}
+	return execConfig, nil
+}
diff --git a/daemon/mgr/image.go b/daemon/mgr/image.go
index 876b6fbd7..2549dfe77 100644
--- a/daemon/mgr/image.go
+++ b/daemon/mgr/image.go
@@ -26,15 +26,15 @@ type ImageMgr interface {
 	// PullImage pulls images from specified registry.
 	PullImage(ctx context.Context, ref string, authConfig *types.AuthConfig, out io.Writer) error
 
+	// GetImage returns imageInfo by reference or id.
+	GetImage(ctx context.Context, idOrRef string) (*types.ImageInfo, error)
+
 	// ListImages lists images stored by containerd.
 	ListImages(ctx context.Context, filter ...string) ([]types.ImageInfo, error)
 
 	// Search Images from specified registry.
 	SearchImages(ctx context.Context, name string, registry string) ([]types.SearchResultItem, error)
 
-	// GetImage returns imageInfo by reference or id.
-	GetImage(ctx context.Context, idOrRef string) (*types.ImageInfo, error)
-
 	// RemoveImage deletes an image by reference.
 	RemoveImage(ctx context.Context, idOrRef string, force bool) error
 
@@ -81,80 +81,6 @@ func NewImageManager(cfg *config.Config, client ctrd.APIClient) (*ImageManager,
 	return mgr, nil
 }
 
-// CheckReference returns image ID and actual reference.
-func (mgr *ImageManager) CheckReference(ctx context.Context, idOrRef string) (actualID digest.Digest, actualRef reference.Named, primaryRef reference.Named, err error) {
-	var namedRef reference.Named
-
-	namedRef, err = reference.Parse(idOrRef)
-	if err != nil {
-		return
-	}
-
-	// NOTE: we cannot add default registry for the idOrRef directly
-	// because the idOrRef maybe short ID or ID. we should run search
-	// without addDefaultRegistryIfMissing at first round.
-	actualID, actualRef, err = mgr.localStore.Search(namedRef)
-	if err != nil {
-		if !errtypes.IsNotfound(err) {
-			return
-		}
-
-		newIDOrRef := addDefaultRegistryIfMissing(idOrRef, mgr.DefaultRegistry, mgr.DefaultNamespace)
-		if newIDOrRef == idOrRef {
-			return
-		}
-
-		// ideally, the err should be nil
-		namedRef, err = reference.Parse(newIDOrRef)
-		if err != nil {
-			return
-		}
-
-		actualID, actualRef, err = mgr.localStore.Search(namedRef)
-		if err != nil {
-			return
-		}
-	}
-
-	// NOTE: if the actualRef is short ID or ID, the primaryRef is first one of
-	// primary reference
-	if reference.IsNamedOnly(actualRef) {
-		refs := mgr.localStore.GetPrimaryReferences(actualID)
-		if len(refs) == 0 {
-			err = errtypes.ErrNotfound
-			logrus.Errorf("one Image ID must have the primary references, but got nothing")
-			return
-		}
-
-		primaryRef = refs[0]
-	} else {
-		primaryRef, err = mgr.localStore.GetPrimaryReference(actualRef)
-		if err != nil {
-			return
-		}
-	}
-	return
-}
-
-// GetImage returns imageInfo by reference.
-func (mgr *ImageManager) GetImage(ctx context.Context, idOrRef string) (*types.ImageInfo, error) {
-	_, _, ref, err := mgr.CheckReference(ctx, idOrRef)
-	if err != nil {
-		return nil, err
-	}
-
-	img, err := mgr.client.GetImage(ctx, ref.String())
-	if err != nil {
-		return nil, err
-	}
-
-	imgInfo, err := mgr.containerdImageToImageInfo(ctx, img)
-	if err != nil {
-		return nil, err
-	}
-	return &imgInfo, nil
-}
-
 // PullImage pulls images from specified registry.
 func (mgr *ImageManager) PullImage(ctx context.Context, ref string, authConfig *types.AuthConfig, out io.Writer) error {
 	newRef := addDefaultRegistryIfMissing(ref, mgr.DefaultRegistry, mgr.DefaultNamespace)
@@ -185,6 +111,25 @@ func (mgr *ImageManager) PullImage(ctx context.Context, ref string, authConfig *
 	return mgr.storeImageReference(ctx, img)
 }
 
+// GetImage returns imageInfo by reference.
+func (mgr *ImageManager) GetImage(ctx context.Context, idOrRef string) (*types.ImageInfo, error) {
+	_, _, ref, err := mgr.CheckReference(ctx, idOrRef)
+	if err != nil {
+		return nil, err
+	}
+
+	img, err := mgr.client.GetImage(ctx, ref.String())
+	if err != nil {
+		return nil, err
+	}
+
+	imgInfo, err := mgr.containerdImageToImageInfo(ctx, img)
+	if err != nil {
+		return nil, err
+	}
+	return &imgInfo, nil
+}
+
 // ListImages lists images stored by containerd.
 func (mgr *ImageManager) ListImages(ctx context.Context, filter ...string) ([]types.ImageInfo, error) {
 	imgs, err := mgr.client.ListImages(ctx, filter...)
@@ -277,6 +222,61 @@ func (mgr *ImageManager) RemoveImage(ctx context.Context, idOrRef string, force
 	return mgr.localStore.RemoveReference(id, namedRef)
 }
 
+// CheckReference returns image ID and actual reference.
+func (mgr *ImageManager) CheckReference(ctx context.Context, idOrRef string) (actualID digest.Digest, actualRef reference.Named, primaryRef reference.Named, err error) {
+	var namedRef reference.Named
+
+	namedRef, err = reference.Parse(idOrRef)
+	if err != nil {
+		return
+	}
+
+	// NOTE: we cannot add default registry for the idOrRef directly
+	// because the idOrRef maybe short ID or ID. we should run search
+	// without addDefaultRegistryIfMissing at first round.
+	actualID, actualRef, err = mgr.localStore.Search(namedRef)
+	if err != nil {
+		if !errtypes.IsNotfound(err) {
+			return
+		}
+
+		newIDOrRef := addDefaultRegistryIfMissing(idOrRef, mgr.DefaultRegistry, mgr.DefaultNamespace)
+		if newIDOrRef == idOrRef {
+			return
+		}
+
+		// ideally, the err should be nil
+		namedRef, err = reference.Parse(newIDOrRef)
+		if err != nil {
+			return
+		}
+
+		actualID, actualRef, err = mgr.localStore.Search(namedRef)
+		if err != nil {
+			return
+		}
+	}
+
+	// NOTE: if the actualRef is short ID or ID, the primaryRef is first one of
+	// primary reference
+	if reference.IsNamedOnly(actualRef) {
+		refs := mgr.localStore.GetPrimaryReferences(actualID)
+		if len(refs) == 0 {
+			err = errtypes.ErrNotfound
+			logrus.Errorf("one Image ID must have the primary references, but got nothing")
+			return
+		}
+
+		primaryRef = refs[0]
+	} else {
+		primaryRef, err = mgr.localStore.GetPrimaryReference(actualRef)
+		if err != nil {
+			return
+		}
+	}
+	return
+}
+
 // updateLocalStore updates the local store.
 func (mgr *ImageManager) updateLocalStore() error {
 	ctx, cancel := context.WithTimeout(context.Background(), deadlineLoadImagesAtBootup)
diff --git a/daemon/mgr/network.go b/daemon/mgr/network.go
index 0ff450802..9c174cedf 100644
--- a/daemon/mgr/network.go
+++ b/daemon/mgr/network.go
@@ -32,26 +32,26 @@ type NetworkMgr interface {
 	// Create is used to create network.
 	Create(ctx context.Context, create apitypes.NetworkCreateConfig) (*types.Network, error)
 
-	// NetworkRemove is used to delete an existing network.
-	Remove(ctx context.Context, name string) error
+	// Get returns the information of network that specified name/id.
+	Get(ctx context.Context, name string) (*types.Network, error)
 
 	// List returns all networks on this host.
 	List(ctx context.Context, labels map[string]string) ([]*types.Network, error)
 
-	// Get returns the information of network that specified name/id.
-	Get(ctx context.Context, name string) (*types.Network, error)
+	// NetworkRemove is used to delete an existing network.
+	Remove(ctx context.Context, name string) error
 
 	// EndpointCreate is used to create network endpoint.
 	EndpointCreate(ctx context.Context, endpoint *types.Endpoint) (string, error)
 
-	// EndpointRemove is used to remove network endpoint.
-	EndpointRemove(ctx context.Context, endpoint *types.Endpoint) error
+	// EndpointInfo returns the information of endpoint that specified name/id.
+	EndpointInfo(ctx context.Context, name string) (*types.Endpoint, error)
 
 	// EndpointList returns all endpoints.
 	EndpointList(ctx context.Context) ([]*types.Endpoint, error)
 
-	// EndpointInfo returns the information of endpoint that specified name/id.
-	EndpointInfo(ctx context.Context, name string) (*types.Endpoint, error)
+	// EndpointRemove is used to remove network endpoint.
+	EndpointRemove(ctx context.Context, endpoint *types.Endpoint) error
 
 	// Controller returns the network controller.
 	Controller() libnetwork.NetworkController
@@ -119,20 +119,24 @@ func (nm *NetworkManager) Create(ctx context.Context, create apitypes.NetworkCre
 	return &network, nil
 }
 
-// Remove is used to delete an existing network.
-func (nm *NetworkManager) Remove(ctx context.Context, name string) error {
-	nw, err := nm.controller.NetworkByName(name)
-	if err != nil {
-		if err == libnetwork.ErrNoSuchNetwork(name) {
-			return errors.Wrap(errtypes.ErrNotfound, err.Error())
-		}
-		return err
+// Get returns the information of network for specified string that represent network name or ID.
+// If network name is given, the network with same name is returned.
+// If prefix of network ID is given, the network with same prefix is returned.
+func (nm *NetworkManager) Get(ctx context.Context, idName string) (*types.Network, error) {
+	n, err := nm.GetNetworkByName(idName)
+	if err != nil && !isNoSuchNetworkError(err) {
+		return nil, err
 	}
-	if nw == nil {
-		return nil
+
+	if n != nil {
+		return n, nil
 	}
 
-	return nw.Delete()
+	n, err = nm.GetNetworkByPartialID(idName)
+	if err != nil {
+		return nil, err
+	}
+	return n, err
 }
 
 // List returns all networks on this host.
@@ -151,6 +155,22 @@ func (nm *NetworkManager) List(ctx context.Context, labels map[string]string) ([
 	return net, nil
 }
 
+// Remove is used to delete an existing network.
+func (nm *NetworkManager) Remove(ctx context.Context, name string) error {
+	nw, err := nm.controller.NetworkByName(name)
+	if err != nil {
+		if err == libnetwork.ErrNoSuchNetwork(name) {
+			return errors.Wrap(errtypes.ErrNotfound, err.Error())
+		}
+		return err
+	}
+	if nw == nil {
+		return nil
+	}
+
+	return nw.Delete()
+}
+
 // GetNetworkByName returns the information of network that specified name.
 func (nm *NetworkManager) GetNetworkByName(name string) (*types.Network, error) {
 	n, err := nm.controller.NetworkByName(name)
@@ -165,26 +185,6 @@ func (nm *NetworkManager) GetNetworkByName(name string) (*types.Network, error)
 	}, nil
 }
 
-// GetNetworksByPartialID returns a list of networks that ID starts with the given prefix.
-func (nm *NetworkManager) GetNetworksByPartialID(partialID string) []*types.Network {
-	var matchedNetworks []*types.Network
-
-	walker := func(nw libnetwork.Network) bool {
-		if strings.HasPrefix(nw.ID(), partialID) {
-			matchedNetwork := &types.Network{
-				Name:    nw.Name(),
-				ID:      nw.ID(),
-				Type:    nw.Type(),
-				Network: nw,
-			}
-			matchedNetworks = append(matchedNetworks, matchedNetwork)
-		}
-		return false
-	}
-	nm.controller.WalkNetworks(walker)
-	return matchedNetworks
-}
-
 // GetNetworkByPartialID returns the information of network that ID starts with the given prefix.
 // If there are not matching networks, it fails with ErrNotfound.
 // If there are multiple matching networks, it fails with ErrTooMany.
@@ -211,32 +211,32 @@ func (nm *NetworkManager) GetNetworkByPartialID(partialID string) (*types.Networ
 	return matchedNetworks[0], nil
 }
 
+// GetNetworksByPartialID returns a list of networks that ID starts with the given prefix.
+func (nm *NetworkManager) GetNetworksByPartialID(partialID string) []*types.Network {
+	var matchedNetworks []*types.Network
+
+	walker := func(nw libnetwork.Network) bool {
+		if strings.HasPrefix(nw.ID(), partialID) {
+			matchedNetwork := &types.Network{
+				Name:    nw.Name(),
+				ID:      nw.ID(),
+				Type:    nw.Type(),
+				Network: nw,
+			}
+			matchedNetworks = append(matchedNetworks, matchedNetwork)
+		}
+		return false
+	}
+	nm.controller.WalkNetworks(walker)
+	return matchedNetworks
+}
+
 // isNoSuchNetworkError looks up the error type and returns a bool if it is ErrNoSuchNetwork or not.
 func isNoSuchNetworkError(err error) bool {
 	_, ok := err.(libnetwork.ErrNoSuchNetwork)
 	return ok
 }
 
-// Get returns the information of network for specified string that represent network name or ID.
-// If network name is given, the network with same name is returned.
-// If prefix of network ID is given, the network with same prefix is returned.
-func (nm *NetworkManager) Get(ctx context.Context, idName string) (*types.Network, error) {
-	n, err := nm.GetNetworkByName(idName)
-	if err != nil && !isNoSuchNetworkError(err) {
-		return nil, err
-	}
-
-	if n != nil {
-		return n, nil
-	}
-
-	n, err = nm.GetNetworkByPartialID(idName)
-	if err != nil {
-		return nil, err
-	}
-	return n, err
-}
-
 // EndpointCreate is used to create network endpoint.
 func (nm *NetworkManager) EndpointCreate(ctx context.Context, endpoint *types.Endpoint) (string, error) {
 	containerID := endpoint.Owner
@@ -330,6 +330,18 @@ func (nm *NetworkManager) EndpointCreate(ctx context.Context, endpoint *types.En
 	return endpointName, nil
 }
 
+// EndpointInfo returns the information of endpoint that specified name/id.
+func (nm *NetworkManager) EndpointInfo(ctx context.Context, name string) (*types.Endpoint, error) {
+	// TODO
+	return nil, nil
+}
+
+// EndpointList returns all endpoints.
+func (nm *NetworkManager) EndpointList(ctx context.Context) ([]*types.Endpoint, error) {
+	// TODO
+	return nil, nil
+}
+
 // EndpointRemove is used to remove network endpoint.
 func (nm *NetworkManager) EndpointRemove(ctx context.Context, endpoint *types.Endpoint) error {
 	sid := endpoint.NetworkConfig.SandboxID
@@ -358,18 +370,6 @@ func (nm *NetworkManager) EndpointRemove(ctx context.Context, endpoint *types.En
 	return nil
 }
 
-// EndpointList returns all endpoints.
-func (nm *NetworkManager) EndpointList(ctx context.Context) ([]*types.Endpoint, error) {
-	// TODO
-	return nil, nil
-}
-
-// EndpointInfo returns the information of endpoint that specified name/id.
-func (nm *NetworkManager) EndpointInfo(ctx context.Context, name string) (*types.Endpoint, error) {
-	// TODO
-	return nil, nil
-}
-
 // Controller returns the network controller.
 func (nm *NetworkManager) Controller() libnetwork.NetworkController {
 	return nm.controller
diff --git a/daemon/mgr/volume.go b/daemon/mgr/volume.go
index 6861ffd37..bc5fd6d51 100644
--- a/daemon/mgr/volume.go
+++ b/daemon/mgr/volume.go
@@ -18,14 +18,14 @@ type VolumeMgr interface {
 	// Create is used to create volume.
 	Create(ctx context.Context, name, driver string, options, labels map[string]string) error
 
-	// Remove is used to delete an existing volume.
-	Remove(ctx context.Context, name string) error
+	// Get returns the information of volume that specified name/id.
+	Get(ctx context.Context, name string) (*types.Volume, error)
 
 	// List returns all volumes on this host.
 	List(ctx context.Context, labels map[string]string) ([]*types.Volume, error)
 
-	// Get returns the information of volume that specified name/id.
-	Get(ctx context.Context, name string) (*types.Volume, error)
+	// Remove is used to delete an existing volume.
+	Remove(ctx context.Context, name string) error
 
 	// Path returns the mount path of volume.
 	Path(ctx context.Context, name string) (string, error)
@@ -91,28 +91,19 @@ func (vm *VolumeManager) Create(ctx context.Context, name, driver string, option
 	return vm.core.CreateVolume(id)
 }
 
-// Remove is used to delete an existing volume.
-func (vm *VolumeManager) Remove(ctx context.Context, name string) error {
-	vol, err := vm.Get(ctx, name)
-	if err != nil {
-		return errors.Wrapf(err, "failed to get volume: %s", name)
-	}
-
-	ref := vol.Option(types.OptionRef)
-	if ref != "" {
-		return errors.Wrapf(errtypes.ErrUsingbyContainers, "failed to remove volume: %s", name)
-	}
-
+// Get returns the information of volume that specified name/id.
+func (vm *VolumeManager) Get(ctx context.Context, name string) (*types.Volume, error) {
 	id := types.VolumeID{
 		Name: name,
 	}
-	if err := vm.core.RemoveVolume(id); err != nil {
+	vol, err := vm.core.GetVolume(id)
+	if err != nil {
 		if strings.Contains(err.Error(), "not found") {
-			return errors.Wrap(errtypes.ErrNotfound, err.Error())
+			return nil, errors.Wrap(errtypes.ErrNotfound, err.Error())
 		}
+		return nil, err
 	}
-
-	return nil
+	return vol, nil
 }
 
 // List returns all volumes on this host.
@@ -129,19 +120,28 @@ func (vm *VolumeManager) List(ctx context.Context, labels map[string]string) ([]
 	return vm.core.ListVolumes(labels)
 }
 
-// Get returns the information of volume that specified name/id.
-func (vm *VolumeManager) Get(ctx context.Context, name string) (*types.Volume, error) {
+// Remove is used to delete an existing volume.
+func (vm *VolumeManager) Remove(ctx context.Context, name string) error {
+	vol, err := vm.Get(ctx, name)
+	if err != nil {
+		return errors.Wrapf(err, "failed to get volume: %s", name)
+	}
+
+	ref := vol.Option(types.OptionRef)
+	if ref != "" {
+		return errors.Wrapf(errtypes.ErrUsingbyContainers, "failed to remove volume: %s", name)
+	}
+
 	id := types.VolumeID{
 		Name: name,
 	}
-	vol, err := vm.core.GetVolume(id)
-	if err != nil {
+	if err := vm.core.RemoveVolume(id); err != nil {
 		if strings.Contains(err.Error(), "not found") {
-			return nil, errors.Wrap(errtypes.ErrNotfound, err.Error())
+			return errors.Wrap(errtypes.ErrNotfound, err.Error())
 		}
-		return nil, err
 	}
-	return vol, nil
+
+	return nil
 }
 
 // Path returns the mount path of volume.