api: remove code for container stats on api < v1.21

API v1.23 and older are deprecated, so we can remove the code to adjust
responses for API v1.20 and lower.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

api/server/router/container/container_routes.go

@@ -111,14 +111,11 @@ func (s *containerRouter) getContainersStats(ctx context.Context, w http.Respons
 		oneShot = httputils.BoolValueOrDefault(r, "one-shot", false)
 	}
 
-	config := &backend.ContainerStatsConfig{
+	return s.backend.ContainerStats(ctx, vars["name"], &backend.ContainerStatsConfig{
 		Stream:    stream,
 		OneShot:   oneShot,
 		OutStream: w,
-		Version:   httputils.VersionFromContext(ctx),
-	}
-
-	return s.backend.ContainerStats(ctx, vars["name"], config)
+	})
 }
 
 func (s *containerRouter) getContainersLogs(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {

api/types/backend/backend.go

@@ -89,7 +89,6 @@ type ContainerStatsConfig struct {
 	Stream    bool
 	OneShot   bool
 	OutStream io.Writer
-	Version   string
 }
 
 // ExecInspect holds information about a running process started

api/types/versions/README.md

@@ -1,14 +0,0 @@
-# Legacy API type versions
-
-This package includes types for legacy API versions. The stable version of the API types live in `api/types/*.go`.
-
-Consider moving a type here when you need to keep backwards compatibility in the API. This legacy types are organized by the latest API version they appear in. For instance, types in the `v1p19` package are valid for API versions below or equal `1.19`. Types in the `v1p20` package are valid for the API version `1.20`, since the versions below that will use the legacy types in `v1p19`.
-
-## Package name conventions
-
-The package name convention is to use `v` as a prefix for the version number and `p`(patch) as a separator. We use this nomenclature due to a few restrictions in the Go package name convention:
-
-1. We cannot use `.` because it's interpreted by the language, think of `v1.20.CallFunction`.
-2. We cannot use `_` because golint complains about it. The code is actually valid, but it looks probably more weird: `v1_20.CallFunction`.
-
-For instance, if you want to modify a type that was available in the version `1.21` of the API but it will have different fields in the version `1.22`, you want to create a new package under `api/types/versions/v1p21`.

api/types/versions/v1p20/types.go

@@ -1,40 +0,0 @@
-// Package v1p20 provides specific API types for the API version 1, patch 20.
-package v1p20 // import "github.com/docker/docker/api/types/versions/v1p20"
-
-import (
-	"github.com/docker/docker/api/types"
-	"github.com/docker/docker/api/types/container"
-	"github.com/docker/go-connections/nat"
-)
-
-// ContainerJSON is a backcompatibility struct for the API 1.20
-type ContainerJSON struct {
-	*types.ContainerJSONBase
-	Mounts          []types.MountPoint
-	Config          *ContainerConfig
-	NetworkSettings *NetworkSettings
-}
-
-// ContainerConfig is a backcompatibility struct used in ContainerJSON for the API 1.20
-type ContainerConfig struct {
-	*container.Config
-
-	MacAddress      string
-	NetworkDisabled bool
-	ExposedPorts    map[nat.Port]struct{}
-
-	// backward compatibility, they now live in HostConfig
-	VolumeDriver string
-}
-
-// StatsJSON is a backcompatibility struct used in Stats for APIs prior to 1.21
-type StatsJSON struct {
-	types.Stats
-	Network types.NetworkStats `json:"network,omitempty"`
-}
-
-// NetworkSettings is a backward compatible struct for APIs prior to 1.21
-type NetworkSettings struct {
-	types.NetworkSettingsBase
-	types.DefaultNetworkSettings
-}

daemon/stats.go

@@ -10,8 +10,6 @@ import (
 	"github.com/containerd/log"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/backend"
-	"github.com/docker/docker/api/types/versions"
-	"github.com/docker/docker/api/types/versions/v1p20"
 	"github.com/docker/docker/container"
 	"github.com/docker/docker/errdefs"
 	"github.com/docker/docker/pkg/ioutils"
@@ -20,13 +18,6 @@ import (
 // ContainerStats writes information about the container to the stream
 // given in the config object.
 func (daemon *Daemon) ContainerStats(ctx context.Context, prefixOrName string, config *backend.ContainerStatsConfig) error {
-	// Engine API version (used for backwards compatibility)
-	apiVersion := config.Version
-
-	if isWindows && versions.LessThan(apiVersion, "1.21") {
-		return errors.New("API versions pre v1.21 do not support stats on Windows")
-	}
-
 	ctr, err := daemon.GetContainer(prefixOrName)
 	if err != nil {
 		return err
@@ -87,46 +78,7 @@ func (daemon *Daemon) ContainerStats(ctx context.Context, prefixOrName string, c
 				return nil
 			}
 
-			var statsJSON interface{}
-			statsJSONPost120 := getStatJSON(v)
-			if versions.LessThan(apiVersion, "1.21") {
-				var (
-					rxBytes   uint64
-					rxPackets uint64
-					rxErrors  uint64
-					rxDropped uint64
-					txBytes   uint64
-					txPackets uint64
-					txErrors  uint64
-					txDropped uint64
-				)
-				for _, v := range statsJSONPost120.Networks {
-					rxBytes += v.RxBytes
-					rxPackets += v.RxPackets
-					rxErrors += v.RxErrors
-					rxDropped += v.RxDropped
-					txBytes += v.TxBytes
-					txPackets += v.TxPackets
-					txErrors += v.TxErrors
-					txDropped += v.TxDropped
-				}
-				statsJSON = &v1p20.StatsJSON{
-					Stats: statsJSONPost120.Stats,
-					Network: types.NetworkStats{
-						RxBytes:   rxBytes,
-						RxPackets: rxPackets,
-						RxErrors:  rxErrors,
-						RxDropped: rxDropped,
-						TxBytes:   txBytes,
-						TxPackets: txPackets,
-						TxErrors:  txErrors,
-						TxDropped: txDropped,
-					},
-				}
-			} else {
-				statsJSON = statsJSONPost120
-			}
-
+			statsJSON := getStatJSON(v)
 			if !config.Stream && noStreamFirstFrame {
 				// prime the cpu stats so they aren't 0 in the final output
 				noStreamFirstFrame = false

integration-cli/docker_api_stats_test.go

@@ -8,13 +8,11 @@ import (
 	"runtime"
 	"strconv"
 	"strings"
-	"sync"
 	"testing"
 	"time"
 
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/system"
-	"github.com/docker/docker/api/types/versions"
 	"github.com/docker/docker/client"
 	"github.com/docker/docker/integration-cli/cli"
 	"github.com/docker/docker/testutil"
@@ -166,27 +164,13 @@ func (s *DockerAPISuite) TestAPIStatsNetworkStats(c *testing.T) {
 }
 
 func (s *DockerAPISuite) TestAPIStatsNetworkStatsVersioning(c *testing.T) {
-	// Windows doesn't support API versions less than 1.25, so no point testing 1.17 .. 1.21
 	testRequires(c, testEnv.IsLocalDaemon, DaemonIsLinux)
 
 	id := runSleepingContainer(c)
 	cli.WaitRun(c, id)
-	wg := sync.WaitGroup{}
-
-	for i := 17; i <= 21; i++ {
-		wg.Add(1)
-		go func(i int) {
-			defer wg.Done()
-			apiVersion := fmt.Sprintf("v1.%d", i)
-			statsJSONBlob := getVersionedStats(c, id, apiVersion)
-			if versions.LessThan(apiVersion, "v1.21") {
-				assert.Assert(c, jsonBlobHasLTv121NetworkStats(statsJSONBlob), "Stats JSON blob from API %s %#v does not look like a <v1.21 API stats structure", apiVersion, statsJSONBlob)
-			} else {
-				assert.Assert(c, jsonBlobHasGTE121NetworkStats(statsJSONBlob), "Stats JSON blob from API %s %#v does not look like a >=v1.21 API stats structure", apiVersion, statsJSONBlob)
-			}
-		}(i)
-	}
-	wg.Wait()
+
+	statsJSONBlob := getStats(c, id)
+	assert.Assert(c, jsonBlobHasGTE121NetworkStats(statsJSONBlob), "Stats JSON blob from API does not look like a >=v1.21 API stats structure", statsJSONBlob)
 }
 
 func getNetworkStats(c *testing.T, id string) map[string]types.NetworkStats {
@@ -202,14 +186,15 @@ func getNetworkStats(c *testing.T, id string) map[string]types.NetworkStats {
 	return st.Networks
 }
 
-// getVersionedStats returns stats result for the
+// getStats returns stats result for the
 // container with id using an API call with version apiVersion. Since the
 // stats result type differs between API versions, we simply return
 // map[string]interface{}.
-func getVersionedStats(c *testing.T, id string, apiVersion string) map[string]interface{} {
+func getStats(c *testing.T, id string) map[string]interface{} {
+	c.Helper()
 	stats := make(map[string]interface{})
 
-	_, body, err := request.Get(testutil.GetContext(c), "/"+apiVersion+"/containers/"+id+"/stats?stream=false")
+	_, body, err := request.Get(testutil.GetContext(c), "/containers/"+id+"/stats?stream=false")
 	assert.NilError(c, err)
 	defer body.Close()
 
@@ -219,23 +204,6 @@ func getVersionedStats(c *testing.T, id string, apiVersion string) map[string]in
 	return stats
 }
 
-func jsonBlobHasLTv121NetworkStats(blob map[string]interface{}) bool {
-	networkStatsIntfc, ok := blob["network"]
-	if !ok {
-		return false
-	}
-	networkStats, ok := networkStatsIntfc.(map[string]interface{})
-	if !ok {
-		return false
-	}
-	for _, expectedKey := range expectedNetworkInterfaceStats {
-		if _, ok := networkStats[expectedKey]; !ok {
-			return false
-		}
-	}
-	return true
-}
-
 func jsonBlobHasGTE121NetworkStats(blob map[string]interface{}) bool {
 	networksStatsIntfc, ok := blob["networks"]
 	if !ok {