plugins: set OTEL_RESOURCE_ATTRIBUTES when invoking a plugin

cli-plugins/manager/cobra.go

@@ -2,11 +2,14 @@ package manager
 
 import (
 	"fmt"
+	"net/url"
 	"os"
+	"strings"
 	"sync"
 
 	"github.com/docker/cli/cli/command"
 	"github.com/spf13/cobra"
+	"go.opentelemetry.io/otel/attribute"
 )
 
 const (
@@ -30,6 +33,10 @@ const (
 	// is, one which failed it's candidate test) and contains the
 	// reason for the failure.
 	CommandAnnotationPluginInvalid = "com.docker.cli.plugin-invalid"
+
+	// CommandAnnotationPluginCommandPath is added to overwrite the
+	// command path for a plugin invocation.
+	CommandAnnotationPluginCommandPath = "com.docker.cli.plugin.command_path"
 )
 
 var pluginCommandStubsOnce sync.Once
@@ -98,3 +105,44 @@ func AddPluginCommandStubs(dockerCli command.Cli, rootCmd *cobra.Command) (err e
 	})
 	return err
 }
+
+const (
+	dockerCliAttributePrefix = attribute.Key("docker.cli")
+
+	cobraCommandPath = attribute.Key("cobra.command_path")
+)
+
+func getPluginResourceAttributes(cmd *cobra.Command, plugin Plugin) attribute.Set {
+	commandPath := cmd.Annotations[CommandAnnotationPluginCommandPath]
+	if commandPath == "" {
+		commandPath = fmt.Sprintf("%s %s", cmd.CommandPath(), plugin.Name)
+	}
+
+	attrSet := attribute.NewSet(
+		cobraCommandPath.String(commandPath),
+	)
+
+	kvs := make([]attribute.KeyValue, 0, attrSet.Len())
+	for iter := attrSet.Iter(); iter.Next(); {
+		attr := iter.Attribute()
+		kvs = append(kvs, attribute.KeyValue{
+			Key:   dockerCliAttributePrefix + "." + attr.Key,
+			Value: attr.Value,
+		})
+	}
+	return attribute.NewSet(kvs...)
+}
+
+func appendPluginResourceAttributesEnvvar(env []string, cmd *cobra.Command, plugin Plugin) []string {
+	if attrs := getPluginResourceAttributes(cmd, plugin); attrs.Len() > 0 {
+		// values in environment variables need to be in baggage format
+		// otel/baggage package can be used after update to v1.22, currently it encodes incorrectly
+		attrsSlice := make([]string, attrs.Len())
+		for iter := attrs.Iter(); iter.Next(); {
+			i, v := iter.IndexedAttribute()
+			attrsSlice[i] = string(v.Key) + "=" + url.PathEscape(v.Value.AsString())
+		}
+		env = append(env, ResourceAttributesEnvvar+"="+strings.Join(attrsSlice, ","))
+	}
+	return env
+}

cli-plugins/manager/manager.go

@@ -17,11 +17,17 @@ import (
 	"golang.org/x/sync/errgroup"
 )
 
-// ReexecEnvvar is the name of an ennvar which is set to the command
-// used to originally invoke the docker CLI when executing a
-// plugin. Assuming $PATH and $CWD remain unchanged this should allow
-// the plugin to re-execute the original CLI.
-const ReexecEnvvar = "DOCKER_CLI_PLUGIN_ORIGINAL_CLI_COMMAND"
+const (
+	// ReexecEnvvar is the name of an ennvar which is set to the command
+	// used to originally invoke the docker CLI when executing a
+	// plugin. Assuming $PATH and $CWD remain unchanged this should allow
+	// the plugin to re-execute the original CLI.
+	ReexecEnvvar = "DOCKER_CLI_PLUGIN_ORIGINAL_CLI_COMMAND"
+
+	// ResourceAttributesEnvvar is the name of the envvar that includes additional
+	// resource attributes for OTEL.
+	ResourceAttributesEnvvar = "OTEL_RESOURCE_ATTRIBUTES"
+)
 
 // errPluginNotFound is the error returned when a plugin could not be found.
 type errPluginNotFound string
@@ -236,6 +242,7 @@ func PluginRunCommand(dockerCli command.Cli, name string, rootcmd *cobra.Command
 
 		cmd.Env = os.Environ()
 		cmd.Env = append(cmd.Env, ReexecEnvvar+"="+os.Args[0])
+		cmd.Env = appendPluginResourceAttributesEnvvar(cmd.Env, rootcmd, plugin)
 
 		return cmd, nil
 	}

cmd/docker/builder.go

@@ -69,7 +69,7 @@ func processBuilder(dockerCli command.Cli, cmd *cobra.Command, args, osargs []st
 	}
 
 	// is this a build that should be forwarded to the builder?
-	fwargs, fwosargs, forwarded := forwardBuilder(builderAlias, args, osargs)
+	fwargs, fwosargs, alias, forwarded := forwardBuilder(builderAlias, args, osargs)
 	if !forwarded {
 		return args, osargs, nil, nil
 	}
@@ -116,10 +116,13 @@ func processBuilder(dockerCli command.Cli, cmd *cobra.Command, args, osargs []st
 		envs = append([]string{"BUILDX_BUILDER=" + dockerCli.CurrentContext()}, envs...)
 	}
 
+	// overwrite the command path for this plugin using the alias name.
+	cmd.Annotations[pluginmanager.CommandAnnotationPluginCommandPath] = fmt.Sprintf("%s %s", cmd.CommandPath(), alias)
+
 	return fwargs, fwosargs, envs, nil
 }
 
-func forwardBuilder(alias string, args, osargs []string) ([]string, []string, bool) {
+func forwardBuilder(alias string, args, osargs []string) ([]string, []string, string, bool) {
 	aliases := [][2][]string{
 		{
 			{"builder"},
@@ -137,10 +140,10 @@ func forwardBuilder(alias string, args, osargs []string) ([]string, []string, bo
 	for _, al := range aliases {
 		if fwargs, changed := command.StringSliceReplaceAt(args, al[0], al[1], 0); changed {
 			fwosargs, _ := command.StringSliceReplaceAt(osargs, al[0], al[1], -1)
-			return fwargs, fwosargs, true
+			return fwargs, fwosargs, al[0][0], true
 		}
 	}
-	return args, osargs, false
+	return args, osargs, "", false
 }
 
 // hasBuilderName checks if a builder name is defined in args or env vars

vendor.mod

@@ -37,6 +37,7 @@ require (
 	github.com/theupdateframework/notary v0.7.1-0.20210315103452-bf96a202a09a
 	github.com/tonistiigi/go-rosetta v0.0.0-20200727161949-f79598599c5d
 	github.com/xeipuuv/gojsonschema v1.2.0
+	go.opentelemetry.io/otel v1.21.0
 	golang.org/x/sync v0.6.0
 	golang.org/x/sys v0.16.0
 	golang.org/x/term v0.15.0
@@ -77,7 +78,6 @@ require (
 	github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415 // indirect
 	go.etcd.io/etcd/raft/v3 v3.5.6 // indirect
 	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.46.1 // indirect
-	go.opentelemetry.io/otel v1.21.0 // indirect
 	go.opentelemetry.io/otel/metric v1.21.0 // indirect
 	go.opentelemetry.io/otel/trace v1.21.0 // indirect
 	golang.org/x/crypto v0.17.0 // indirect