chore: remove config Validate call in docker (#34699)

**Description:** <Describe what has changed.>
<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
Configuration validation is done during collector's startup, making it
redundant when being called inside component's logic. This PR removes
the Validate call done during Dockers's receiver start function.

**Link to tracking Issue:** <Issue number if applicable>

#33498

**Testing:** <Describe what testing was performed and which tests were
added.>
No testing needed to be modified as the `Validate` functionality is
already covered.

**Documentation:** <Describe the documentation added.>

---------

Co-authored-by: Sean Marciniak <[email protected]>

extension/observer/dockerobserver/config.go

@@ -4,7 +4,6 @@
 package dockerobserver // import "github.com/open-telemetry/opentelemetry-collector-contrib/extension/observer/dockerobserver"
 
 import (
-	"errors"
 	"fmt"
 	"time"
 
@@ -15,16 +14,7 @@ import (
 
 // Config defines configuration for docker observer
 type Config struct {
-
-	// The URL of the docker server.  Default is "unix:///var/run/docker.sock" on non-Windows
-	// and "npipe:////./pipe/docker_engine" on Windows
-	Endpoint string `mapstructure:"endpoint"`
-
-	// The maximum amount of time to wait for docker API responses.  Default is 5s
-	Timeout time.Duration `mapstructure:"timeout"`
-
-	// A list of filters whose matching images are to be excluded.  Supports literals, globs, and regex.
-	ExcludedImages []string `mapstructure:"excluded_images"`
+	docker.Config `mapstructure:",squash"`
 
 	// If true, the "Config.Hostname" field (if present) of the docker
 	// container will be used as the discovered host that is used to configure
@@ -47,15 +37,9 @@ type Config struct {
 	// through the docker event listener example: cache_sync_interval: "20m"
 	// Default: "60m"
 	CacheSyncInterval time.Duration `mapstructure:"cache_sync_interval"`
-
-	// Docker client API version. Default is 1.22
-	DockerAPIVersion string `mapstructure:"api_version"`
 }
 
 func (config Config) Validate() error {
-	if config.Endpoint == "" {
-		return errors.New("endpoint must be specified")
-	}
 	if err := docker.VersionIsValidAndGTE(config.DockerAPIVersion, minimumRequiredDockerAPIVersion); err != nil {
 		return err
 	}
@@ -71,14 +55,12 @@ func (config Config) Validate() error {
 func (config *Config) Unmarshal(conf *confmap.Conf) error {
 	err := conf.Unmarshal(config)
 	if err != nil {
-		if floatAPIVersion, ok := conf.Get("api_version").(float64); ok {
-			return fmt.Errorf(
-				"%w.\n\nHint: You may want to wrap the 'api_version' value in quotes (api_version: \"%1.2f\")",
-				err,
-				floatAPIVersion,
-			)
-		}
 		return err
 	}
-	return nil
+
+	if len(config.ExcludedImages) == 0 {
+		config.ExcludedImages = nil
+	}
+
+	return err
 }

extension/observer/dockerobserver/config_test.go

@@ -15,6 +15,7 @@ import (
 	"go.opentelemetry.io/collector/confmap/confmaptest"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/extension/observer/dockerobserver/internal/metadata"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/internal/docker"
 )
 
 var version = "1.40"
@@ -34,14 +35,16 @@ func TestLoadConfig(t *testing.T) {
 		{
 			id: component.NewIDWithName(metadata.Type, "all_settings"),
 			expected: &Config{
-				Endpoint:              "unix:///var/run/docker.sock",
+				Config: docker.Config{
+					Endpoint:         "unix:///var/run/docker.sock",
+					Timeout:          20 * time.Second,
+					ExcludedImages:   []string{"excluded", "image"},
+					DockerAPIVersion: version,
+				},
 				CacheSyncInterval:     5 * time.Minute,
-				Timeout:               20 * time.Second,
-				ExcludedImages:        []string{"excluded", "image"},
 				UseHostnameIfPresent:  true,
 				UseHostBindings:       true,
 				IgnoreNonHostBindings: true,
-				DockerAPIVersion:      version,
 			},
 		},
 	}
@@ -59,19 +62,19 @@ func TestLoadConfig(t *testing.T) {
 }
 
 func TestValidateConfig(t *testing.T) {
-	cfg := &Config{}
+	cfg := &Config{Config: docker.Config{DockerAPIVersion: "1.24", Timeout: 5 * time.Second}, CacheSyncInterval: 5 * time.Second}
 	assert.Equal(t, "endpoint must be specified", component.ValidateConfig(cfg).Error())
 
-	cfg = &Config{Endpoint: "someEndpoint", DockerAPIVersion: "1.23"}
+	cfg = &Config{Config: docker.Config{Endpoint: "someEndpoint", DockerAPIVersion: "1.23"}}
 	assert.Equal(t, `"api_version" 1.23 must be at least 1.24`, component.ValidateConfig(cfg).Error())
 
-	cfg = &Config{Endpoint: "someEndpoint", DockerAPIVersion: version}
+	cfg = &Config{Config: docker.Config{Endpoint: "someEndpoint", DockerAPIVersion: version}}
 	assert.Equal(t, "timeout must be specified", component.ValidateConfig(cfg).Error())
 
-	cfg = &Config{Endpoint: "someEndpoint", DockerAPIVersion: version, Timeout: 5 * time.Minute}
+	cfg = &Config{Config: docker.Config{Endpoint: "someEndpoint", DockerAPIVersion: version, Timeout: 5 * time.Minute}}
 	assert.Equal(t, "cache_sync_interval must be specified", component.ValidateConfig(cfg).Error())
 
-	cfg = &Config{Endpoint: "someEndpoint", DockerAPIVersion: version, Timeout: 5 * time.Minute, CacheSyncInterval: 5 * time.Minute}
+	cfg = &Config{Config: docker.Config{Endpoint: "someEndpoint", DockerAPIVersion: version, Timeout: 5 * time.Minute}, CacheSyncInterval: 5 * time.Minute}
 	assert.Nil(t, component.ValidateConfig(cfg))
 }
 

extension/observer/dockerobserver/extension.go

@@ -26,9 +26,11 @@ var (
 	minimumRequiredDockerAPIVersion = docker.MustNewAPIVersion(defaultDockerAPIVersion)
 )
 
-var _ extension.Extension = (*dockerObserver)(nil)
-var _ observer.EndpointsLister = (*dockerObserver)(nil)
-var _ observer.Observable = (*dockerObserver)(nil)
+var (
+	_ extension.Extension      = (*dockerObserver)(nil)
+	_ observer.EndpointsLister = (*dockerObserver)(nil)
+	_ observer.Observable      = (*dockerObserver)(nil)
+)
 
 type dockerObserver struct {
 	*observer.EndpointsWatcher
@@ -60,11 +62,9 @@ func (d *dockerObserver) Start(ctx context.Context, _ component.Host) error {
 	d.ctx = dCtx
 
 	// Create new Docker client
-	dConfig, err := docker.NewConfig(d.config.Endpoint, d.config.Timeout, d.config.ExcludedImages, d.config.DockerAPIVersion)
-	if err != nil {
-		return err
-	}
+	dConfig := docker.NewConfig(d.config.Endpoint, d.config.Timeout, d.config.ExcludedImages, d.config.DockerAPIVersion)
 
+	var err error
 	d.dClient, err = docker.NewDockerClient(dConfig, d.logger)
 	if err != nil {
 		return fmt.Errorf("could not create docker client: %w", err)
@@ -119,7 +119,6 @@ func (d *dockerObserver) ListEndpoints() []observer.Endpoint {
 // containerEndpoints generates a list of observer.Endpoint given a Docker ContainerJSON.
 // This function will only generate endpoints if a container is in the Running state and not Paused.
 func (d *dockerObserver) containerEndpoints(c *dtypes.ContainerJSON) []observer.Endpoint {
-
 	if !c.State.Running || c.State.Running && c.State.Paused {
 		return nil
 	}

extension/observer/dockerobserver/factory.go

@@ -12,6 +12,7 @@ import (
 	"go.opentelemetry.io/collector/extension"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/extension/observer/dockerobserver/internal/metadata"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/internal/docker"
 )
 
 // NewFactory should be called to create a factory with default values.
@@ -26,10 +27,12 @@ func NewFactory() extension.Factory {
 
 func createDefaultConfig() component.Config {
 	return &Config{
-		Endpoint:          client.DefaultDockerHost,
-		Timeout:           5 * time.Second,
+		Config: docker.Config{
+			Endpoint:         client.DefaultDockerHost,
+			Timeout:          5 * time.Second,
+			DockerAPIVersion: defaultDockerAPIVersion,
+		},
 		CacheSyncInterval: 60 * time.Minute,
-		DockerAPIVersion:  defaultDockerAPIVersion,
 	}
 }
 

internal/docker/config.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/docker/docker/api/types/versions"
 	"github.com/docker/docker/client"
+	"go.opentelemetry.io/collector/confmap"
 )
 
 type Config struct {
@@ -29,16 +30,39 @@ type Config struct {
 	DockerAPIVersion string `mapstructure:"api_version"`
 }
 
+func (config *Config) Unmarshal(conf *confmap.Conf) error {
+	// WithIgonreUnused needed because this configuration is embedded inside other configurations
+	err := conf.Unmarshal(config, confmap.WithIgnoreUnused())
+	if err != nil {
+		if floatAPIVersion, ok := conf.Get("api_version").(float64); ok {
+			return fmt.Errorf(
+				"%w.\n\nHint: You may want to wrap the 'api_version' value in quotes (api_version: \"%1.2f\")",
+				err,
+				floatAPIVersion,
+			)
+		}
+		return err
+	}
+	return nil
+}
+
+func (config Config) Validate() error {
+	if config.Endpoint == "" {
+		return errors.New("endpoint must be specified")
+	}
+	return nil
+}
+
 // NewConfig creates a new config to be used when creating
 // a docker client
-func NewConfig(endpoint string, timeout time.Duration, excludedImages []string, apiVersion string) (*Config, error) {
+func NewConfig(endpoint string, timeout time.Duration, excludedImages []string, apiVersion string) *Config {
 	cfg := &Config{
 		Endpoint:         endpoint,
 		Timeout:          timeout,
 		ExcludedImages:   excludedImages,
 		DockerAPIVersion: apiVersion,
 	}
-	return cfg, cfg.validate()
+	return cfg
 }
 
 // NewDefaultConfig creates a new config with default values
@@ -53,18 +77,6 @@ func NewDefaultConfig() *Config {
 	return cfg
 }
 
-// validate asserts that an endpoint field is set
-// on the config struct
-func (config Config) validate() error {
-	if config.Endpoint == "" {
-		return errors.New("config.Endpoint must be specified")
-	}
-	if err := VersionIsValidAndGTE(config.DockerAPIVersion, minimumRequiredDockerAPIVersion); err != nil {
-		return err
-	}
-	return nil
-}
-
 type apiVersion struct {
 	major int
 	minor int

internal/docker/go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/docker/docker v26.1.5+incompatible
 	github.com/gobwas/glob v0.2.3
 	github.com/stretchr/testify v1.9.0
+	go.opentelemetry.io/collector/confmap v1.14.1
 	go.uber.org/goleak v1.3.0
 	go.uber.org/zap v1.27.0
 )
@@ -20,8 +21,13 @@ require (
 	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/go-logr/logr v1.4.1 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/go-viper/mapstructure/v2 v2.1.0 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
-	github.com/kr/pretty v0.2.1 // indirect
+	github.com/knadh/koanf/maps v0.1.1 // indirect
+	github.com/knadh/koanf/providers/confmap v0.1.0 // indirect
+	github.com/knadh/koanf/v2 v2.1.1 // indirect
+	github.com/mitchellh/copystructure v1.2.0 // indirect
+	github.com/mitchellh/reflectwalk v1.0.2 // indirect
 	github.com/moby/docker-image-spec v1.3.1 // indirect
 	github.com/moby/term v0.0.0-20210619224110-3f7ff695adc6 // indirect
 	github.com/morikuni/aec v1.0.0 // indirect
@@ -39,7 +45,6 @@ require (
 	golang.org/x/net v0.23.0 // indirect
 	golang.org/x/sys v0.18.0 // indirect
 	golang.org/x/time v0.4.0 // indirect
-	gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 	gotest.tools/v3 v3.0.3 // indirect
 )