[receiver/memcached] Migrate memcached scraper to the new metrics bu…

…ilder (#9329)

The v2 generated metrics are scoped to "otelcol/memcachedreceiver" instead of "otelcol/memcached". If this is a breaking change, let me know how we should handle it.

receiver/memcachedreceiver/config.go

@@ -19,6 +19,8 @@ import (
 
 	"go.opentelemetry.io/collector/config/confignet"
 	"go.opentelemetry.io/collector/receiver/scraperhelper"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/memcachedreceiver/internal/metadata"
 )
 
 type Config struct {
@@ -27,4 +29,7 @@ type Config struct {
 
 	// Timeout for the memcache stats request
 	Timeout time.Duration `mapstructure:"timeout"`
+
+	// Metrics allows customizing scraped metrics representation.
+	Metrics metadata.MetricsSettings `mapstructure:"metrics"`
 }

receiver/memcachedreceiver/doc.go

@@ -15,6 +15,6 @@
 //go:build !windows
 // +build !windows
 
-//go:generate mdatagen metadata.yaml
+//go:generate mdatagen --experimental-gen metadata.yaml
 
 package memcachedreceiver // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/memcachedreceiver"

receiver/memcachedreceiver/documentation.md

@@ -20,7 +20,14 @@ These are the metrics available for this scraper.
 | **memcached.operations** | Operation counts. | {operations} | Sum(Int) | <ul> <li>type</li> <li>operation</li> </ul> |
 | **memcached.threads** | Number of threads used by the memcached instance. | {threads} | Sum(Int) | <ul> </ul> |
 
-**Highlighted metrics** are emitted by default.
+**Highlighted metrics** are emitted by default. Other metrics are optional and not emitted by default.
+Any metric can be enabled or disabled with the following scraper configuration:
+
+```yaml
+metrics:
+  <metric_name>:
+    enabled: <true|false>
+```
 
 ## Metric attributes
 

receiver/memcachedreceiver/factory.go

@@ -14,8 +14,6 @@
 
 package memcachedreceiver // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/memcachedreceiver"
 
-//go:generate mdatagen metadata.yaml
-
 import (
 	"context"
 	"time"
@@ -25,6 +23,8 @@ import (
 	"go.opentelemetry.io/collector/config/confignet"
 	"go.opentelemetry.io/collector/consumer"
 	"go.opentelemetry.io/collector/receiver/scraperhelper"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/memcachedreceiver/internal/metadata"
 )
 
 const (
@@ -49,6 +49,7 @@ func createDefaultConfig() config.Receiver {
 		NetAddr: confignet.NetAddr{
 			Endpoint: "localhost:11211",
 		},
+		Metrics: metadata.DefaultMetricsSettings(),
 	}
 }