Follow up work on docker_log input (#6008)

plugins/inputs/docker/docker.go

@@ -20,6 +20,7 @@ import (
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/filter"
 	"github.com/influxdata/telegraf/internal"
+	"github.com/influxdata/telegraf/internal/docker"
 	tlsint "github.com/influxdata/telegraf/internal/tls"
 	"github.com/influxdata/telegraf/plugins/inputs"
 )
@@ -361,44 +362,12 @@ func (d *Docker) gatherInfo(acc telegraf.Accumulator) error {
 	return nil
 }
 
-func parseImage(image string) (string, string) {
-	// Adapts some of the logic from the actual Docker library's image parsing
-	// routines:
-	// https://github.com/docker/distribution/blob/release/2.7/reference/normalize.go
-	domain := ""
-	remainder := ""
-
-	i := strings.IndexRune(image, '/')
-
-	if i == -1 || (!strings.ContainsAny(image[:i], ".:") && image[:i] != "localhost") {
-		remainder = image
-	} else {
-		domain, remainder = image[:i], image[i+1:]
-	}
-
-	imageName := ""
-	imageVersion := "unknown"
-
-	i = strings.LastIndex(remainder, ":")
-	if i > -1 {
-		imageVersion = remainder[i+1:]
-		imageName = remainder[:i]
-	} else {
-		imageName = remainder
-	}
-
-	if domain != "" {
-		imageName = domain + "/" + imageName
-	}
-
-	return imageName, imageVersion
-}
-
 func (d *Docker) gatherContainer(
 	container types.Container,
 	acc telegraf.Accumulator,
 ) error {
 	var v *types.StatsJSON
+
 	// Parse container name
 	var cname string
 	for _, name := range container.Names {
@@ -414,7 +383,7 @@ func (d *Docker) gatherContainer(
 		return nil
 	}
 
-	imageName, imageVersion := parseImage(container.Image)
+	imageName, imageVersion := docker.ParseImage(container.Image)
 
 	tags := map[string]string{
 		"engine_host":       d.engineHost,

plugins/inputs/docker/docker_test.go

@@ -9,10 +9,9 @@ import (
 	"testing"
 	"time"
 
-	"github.com/influxdata/telegraf/testutil"
-
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/swarm"
+	"github.com/influxdata/telegraf/testutil"
 	"github.com/stretchr/testify/require"
 )
 
@@ -945,54 +944,3 @@ func TestContainerName(t *testing.T) {
 		})
 	}
 }
-
-func TestParseImage(t *testing.T) {
-	tests := []struct {
-		image         string
-		parsedName    string
-		parsedVersion string
-	}{
-		{
-			image:         "postgres",
-			parsedName:    "postgres",
-			parsedVersion: "unknown",
-		},
-		{
-			image:         "postgres:latest",
-			parsedName:    "postgres",
-			parsedVersion: "latest",
-		},
-		{
-			image:         "coreos/etcd",
-			parsedName:    "coreos/etcd",
-			parsedVersion: "unknown",
-		},
-		{
-			image:         "coreos/etcd:latest",
-			parsedName:    "coreos/etcd",
-			parsedVersion: "latest",
-		},
-		{
-			image:         "quay.io/postgres",
-			parsedName:    "quay.io/postgres",
-			parsedVersion: "unknown",
-		},
-		{
-			image:         "quay.io:4443/coreos/etcd",
-			parsedName:    "quay.io:4443/coreos/etcd",
-			parsedVersion: "unknown",
-		},
-		{
-			image:         "quay.io:4443/coreos/etcd:latest",
-			parsedName:    "quay.io:4443/coreos/etcd",
-			parsedVersion: "latest",
-		},
-	}
-	for _, tt := range tests {
-		t.Run("parse name "+tt.image, func(t *testing.T) {
-			imageName, imageVersion := parseImage(tt.image)
-			require.Equal(t, tt.parsedName, imageName)
-			require.Equal(t, tt.parsedVersion, imageVersion)
-		})
-	}
-}