feat(inputs.docker): Add disk usage

plugins/inputs/docker/README.md

@@ -53,6 +53,11 @@ See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
   # container_state_include = []
   # container_state_exclude = []
 
+  ## Objects to include for disk usage query
+  ## Allowed values are "container", "image", "volume" 
+  ## When empty disk usage is excluded
+  storage_objects = []
+
   ## Timeout for docker list, info, and stats commands
   timeout = "5s"
 
@@ -379,6 +384,23 @@ status if configured.
     - tasks_desired
     - tasks_running
 
+- docker_disk_usage
+  - tags:
+    - engine_host
+    - server_version
+    - container_name
+    - container_image
+    - container_version
+    - image_id
+    - image_name
+    - image_version
+    - volume_name
+  - fields:
+    - size_rw
+    - size_root_fs
+    - size
+    - shared_size
+
 ## Example Output
 
 ```text

plugins/inputs/docker/client.go

@@ -11,7 +11,6 @@ import (
 )
 
 var (
-	version        = "1.24" // https://docs.docker.com/engine/api/
 	defaultHeaders = map[string]string{"User-Agent": "engine-api-cli-1.0"}
 )
 
@@ -23,6 +22,8 @@ type Client interface {
 	ServiceList(ctx context.Context, options types.ServiceListOptions) ([]swarm.Service, error)
 	TaskList(ctx context.Context, options types.TaskListOptions) ([]swarm.Task, error)
 	NodeList(ctx context.Context, options types.NodeListOptions) ([]swarm.Node, error)
+	DiskUsage(ctx context.Context, options types.DiskUsageOptions) (types.DiskUsage, error)
+	ClientVersion() string
 	Close() error
 }
 
@@ -43,7 +44,7 @@ func NewClient(host string, tlsConfig *tls.Config) (Client, error) {
 	client, err := dockerClient.NewClientWithOpts(
 		dockerClient.WithHTTPHeaders(defaultHeaders),
 		dockerClient.WithHTTPClient(httpClient),
-		dockerClient.WithVersion(version),
+		dockerClient.WithAPIVersionNegotiation(),
 		dockerClient.WithHost(host))
 	if err != nil {
 		return nil, err
@@ -77,6 +78,14 @@ func (c *SocketClient) TaskList(ctx context.Context, options types.TaskListOptio
 func (c *SocketClient) NodeList(ctx context.Context, options types.NodeListOptions) ([]swarm.Node, error) {
 	return c.client.NodeList(ctx, options)
 }
+func (c *SocketClient) DiskUsage(ctx context.Context, options types.DiskUsageOptions) (types.DiskUsage, error) {
+	return c.client.DiskUsage(ctx, options)
+}
+
+func (c *SocketClient) ClientVersion() string {
+	return c.client.ClientVersion()
+}
+
 func (c *SocketClient) Close() error {
 	return c.client.Close()
 }

plugins/inputs/docker/docker.go

@@ -15,6 +15,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/Masterminds/semver/v3"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/filters"
 	"github.com/docker/docker/api/types/swarm"
@@ -53,6 +54,8 @@ type Docker struct {
 	ContainerStateInclude []string `toml:"container_state_include"`
 	ContainerStateExclude []string `toml:"container_state_exclude"`
 
+	StorageObjects []string `toml:"storage_objects"`
+
 	IncludeSourceTag bool `toml:"source_tag"`
 
 	Log telegraf.Logger
@@ -69,6 +72,7 @@ type Docker struct {
 	labelFilter     filter.Filter
 	containerFilter filter.Filter
 	stateFilter     filter.Filter
+	objectTypes     []types.DiskUsageObject
 }
 
 // KB, MB, GB, TB, PB...human friendly
@@ -87,6 +91,9 @@ var (
 	containerStates        = []string{"created", "restarting", "running", "removing", "paused", "exited", "dead"}
 	containerMetricClasses = []string{"cpu", "network", "blkio"}
 	now                    = time.Now
+
+	minVersion          = semver.MustParse("1.23")
+	minDiskUsageVersion = semver.MustParse("1.42")
 )
 
 func (*Docker) SampleConfig() string {
@@ -123,6 +130,21 @@ func (d *Docker) Init() error {
 		}
 	}
 
+	d.objectTypes = make([]types.DiskUsageObject, 0, len(d.StorageObjects))
+
+	for _, object := range d.StorageObjects {
+		switch object {
+		case "container":
+			d.objectTypes = append(d.objectTypes, types.ContainerObject)
+		case "image":
+			d.objectTypes = append(d.objectTypes, types.ImageObject)
+		case "volume":
+			d.objectTypes = append(d.objectTypes, types.VolumeObject)
+		default:
+			d.Log.Warnf("Unrecognized storage object type: %s", object)
+		}
+	}
+
 	return nil
 }
 
@@ -134,6 +156,19 @@ func (d *Docker) Gather(acc telegraf.Accumulator) error {
 			return err
 		}
 		d.client = c
+
+		version, err := semver.NewVersion(d.client.ClientVersion())
+		if err != nil {
+			return err
+		}
+
+		if version.LessThan(minVersion) {
+			d.Log.Warnf("Unsupported api version (%v.%v), upgrade to docker engine 1.12 or later (api version 1.24)",
+				version.Major(), version.Minor())
+		} else if version.LessThan(minDiskUsageVersion) && len(d.objectTypes) > 0 {
+			d.Log.Warnf("Unsupported api version for disk usage (%v.%v), upgrade to docker engine 23.0 or later (api version 1.42)",
+				version.Major(), version.Minor())
+		}
 	}
 
 	// Close any idle connections in the end of gathering
@@ -209,6 +244,11 @@ func (d *Docker) Gather(acc telegraf.Accumulator) error {
 	}
 	wg.Wait()
 
+	// Get disk usage data
+	if len(d.objectTypes) > 0 {
+		d.gatherDiskUsage(acc, types.DiskUsageOptions{Types: d.objectTypes})
+	}
+
 	return nil
 }
 
@@ -412,21 +452,27 @@ func hostnameFromID(id string) string {
 	return id
 }
 
-func (d *Docker) gatherContainer(
-	container types.Container,
-	acc telegraf.Accumulator,
-) error {
-	var v *types.StatsJSON
-
-	// Parse container name
+// Parse container name
+func parseContainerName(containerNames []string) string {
 	var cname string
-	for _, name := range container.Names {
+
+	for _, name := range containerNames {
 		trimmedName := strings.TrimPrefix(name, "/")
 		if !strings.Contains(trimmedName, "/") {
 			cname = trimmedName
-			break
+			return cname
 		}
 	}
+	return cname
+}
+
+func (d *Docker) gatherContainer(
+	container types.Container,
+	acc telegraf.Accumulator,
+) error {
+	var v *types.StatsJSON
+
+	cname := parseContainerName(container.Names)
 
 	if cname == "" {
 		return nil
@@ -849,6 +895,93 @@ func (d *Docker) gatherBlockIOMetrics(
 	}
 }
 
+func (d *Docker) gatherDiskUsage(acc telegraf.Accumulator, opts types.DiskUsageOptions) {
+	ctx, cancel := context.WithTimeout(context.Background(), time.Duration(d.Timeout))
+	defer cancel()
+
+	du, err := d.client.DiskUsage(ctx, opts)
+
+	if err != nil {
+		acc.AddError(err)
+	}
+
+	now := time.Now()
+	duName := "docker_disk_usage"
+
+	// Layers size
+	fields := map[string]interface{}{
+		"layers_size": du.LayersSize,
+	}
+
+	tags := map[string]string{
+		"engine_host":    d.engineHost,
+		"server_version": d.serverVersion,
+	}
+
+	acc.AddFields(duName, fields, tags, now)
+
+	// Containers
+	for _, container := range du.Containers {
+		fields := map[string]interface{}{
+			"size_rw":      container.SizeRw,
+			"size_root_fs": container.SizeRootFs,
+		}
+
+		imageName, imageVersion := dockerint.ParseImage(container.Image)
+
+		tags := map[string]string{
+			"engine_host":       d.engineHost,
+			"server_version":    d.serverVersion,
+			"container_name":    parseContainerName(container.Names),
+			"container_image":   imageName,
+			"container_version": imageVersion,
+		}
+
+		if d.IncludeSourceTag {
+			tags["source"] = hostnameFromID(container.ID)
+		}
+
+		acc.AddFields(duName, fields, tags, now)
+	}
+
+	// Images
+	for _, image := range du.Images {
+		fields := map[string]interface{}{
+			"size":        image.Size,
+			"shared_size": image.SharedSize,
+		}
+
+		tags := map[string]string{
+			"engine_host":    d.engineHost,
+			"server_version": d.serverVersion,
+			"image_id":       image.ID[7:19], // remove "sha256:" and keep the first 12 characters
+		}
+
+		if len(image.RepoTags) > 0 {
+			imageName, imageVersion := dockerint.ParseImage(image.RepoTags[0])
+			tags["image_name"] = imageName
+			tags["image_version"] = imageVersion
+		}
+
+		acc.AddFields(duName, fields, tags, now)
+	}
+
+	// Volumes
+	for _, volume := range du.Volumes {
+		fields := map[string]interface{}{
+			"size": volume.UsageData.Size,
+		}
+
+		tags := map[string]string{
+			"engine_host":    d.engineHost,
+			"server_version": d.serverVersion,
+			"volume_name":    volume.Name,
+		}
+
+		acc.AddFields(duName, fields, tags, now)
+	}
+}
+
 func copyTags(in map[string]string) map[string]string {
 	out := make(map[string]string)
 	for k, v := range in {