api/types/container: StatsResponse: add OSType field

Adds a per-stats OSType field to allow handle the platform-specific fields.
Before this change, the client had to get the OSType field from the server's
API response header and copy it to each record.

Older daemon versions don't have this field, so the client still needs to
handle fallbacks.

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

api/docs/CHANGELOG.md

@@ -69,6 +69,8 @@ keywords: "API, Docker, rcli, REST, documentation"
   of the `Resource` requirements.
 * `GET /tasks/{id}` now  returns `SwapBytes` and `MemorySwappiness` fields as
   part of the `Resource` requirements.
+* `GET /containers/{id}/stats` now returns an `os_type` field to allow platform-
+  specific handling of the stats.
 
 ## v1.51 API changes
 

api/docs/v1.52.yaml

@@ -5639,6 +5639,13 @@ definitions:
         type: "string"
         x-nullable: true
         example: "boring_wozniak"
+      os_type:
+        description: |
+          OSType is the OS of the container ("linux" or "windows") to allow
+          platform-specific handling of stats.
+        type: "string"
+        x-nullable: true
+        example: "linux"
       read:
         description: |
           Date and time at which this sample was collected.

api/swagger.yaml

@@ -5639,6 +5639,13 @@ definitions:
         type: "string"
         x-nullable: true
         example: "boring_wozniak"
+      os_type:
+        description: |
+          OSType is the OS of the container ("linux" or "windows") to allow
+          platform-specific handling of stats.
+        type: "string"
+        x-nullable: true
+        example: "linux"
       read:
         description: |
           Date and time at which this sample was collected.

api/types/container/stats.go

@@ -155,6 +155,10 @@ type StatsResponse struct {
 	// Name is the name of the container for which the stats were collected.
 	Name string `json:"name,omitempty"`
 
+	// OSType is the OS of the container ("linux" or "windows") to allow
+	// platform-specific handling of stats.
+	OSType string `json:"os_type,omitempty"`
+
 	// Read is the date and time at which this sample was collected.
 	Read time.Time `json:"read"`
 

daemon/stats.go

@@ -29,8 +29,9 @@ func (daemon *Daemon) ContainerStats(ctx context.Context, prefixOrName string, c
 		if !ctr.State.IsRunning() || ctr.State.IsRestarting() {
 			// The container is either not running or restarting, return an empty stats.
 			return json.NewEncoder(config.OutStream()).Encode(&containertypes.StatsResponse{
-				Name: ctr.Name,
-				ID:   ctr.ID,
+				ID:     ctr.ID,
+				Name:   ctr.Name,
+				OSType: runtime.GOOS,
 			})
 		}
 		if config.OneShot {
@@ -133,8 +134,9 @@ done:
 		if cerrdefs.IsNotFound(err) || cerrdefs.IsConflict(err) {
 			// return empty stats containing only name and ID if not running or not found
 			return &containertypes.StatsResponse{
-				Name: ctr.Name,
-				ID:   ctr.ID,
+				ID:     ctr.ID,
+				Name:   ctr.Name,
+				OSType: runtime.GOOS,
 			}, nil
 		}
 		log.G(context.TODO()).Errorf("collecting stats for container %s: %v", ctr.Name, err)

daemon/stats/collector.go

@@ -1,6 +1,7 @@
 package stats
 
 import (
+	"runtime"
 	"sync"
 	"time"
 
@@ -109,8 +110,9 @@ func (s *Collector) Run() {
 			stats, err := s.supervisor.GetContainerStats(pair.container)
 			if err != nil {
 				stats = &containertypes.StatsResponse{
-					Name: pair.container.Name,
-					ID:   pair.container.ID,
+					ID:     pair.container.ID,
+					Name:   pair.container.Name,
+					OSType: runtime.GOOS,
 				}
 			}
 			pair.publisher.Publish(*stats)

daemon/stats_unix.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"runtime"
 	"strconv"
 	"strings"
 
@@ -47,9 +48,10 @@ func (daemon *Daemon) stats(c *container.Container) (*containertypes.StatsRespon
 		return nil, err
 	}
 	s := &containertypes.StatsResponse{
-		Name: c.Name,
-		ID:   c.ID,
-		Read: cs.Read,
+		ID:     c.ID,
+		Name:   c.Name,
+		OSType: runtime.GOOS,
+		Read:   cs.Read,
 	}
 	switch t := cs.Metrics.(type) {
 	case *statsV1.Metrics:

daemon/stats_windows.go

@@ -2,6 +2,7 @@ package daemon
 
 import (
 	"context"
+	"runtime"
 
 	cerrdefs "github.com/containerd/errdefs"
 	containertypes "github.com/moby/moby/api/types/container"
@@ -28,8 +29,9 @@ func (daemon *Daemon) stats(c *container.Container) (*containertypes.StatsRespon
 
 	// Start with an empty structure
 	s := &containertypes.StatsResponse{
-		Name:     c.Name,
 		ID:       c.ID,
+		Name:     c.Name,
+		OSType:   runtime.GOOS,
 		Read:     stats.Read,
 		NumProcs: platform.NumProcs(),
 	}

vendor/github.com/moby/moby/api/types/container/stats.go

@@ -155,6 +155,10 @@ type StatsResponse struct {
 	// Name is the name of the container for which the stats were collected.
 	Name string `json:"name,omitempty"`
 
+	// OSType is the OS of the container ("linux" or "windows") to allow
+	// platform-specific handling of stats.
+	OSType string `json:"os_type,omitempty"`
+
 	// Read is the date and time at which this sample was collected.
 	Read time.Time `json:"read"`