Move tracing to plugin

This just makes the implementation a little cleaner.
It also makes the trace exporter pluggable.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>

services/server/config/config.go

@@ -67,8 +67,6 @@ type Config struct {
 	Timeouts map[string]string `toml:"timeouts"`
 	// Imports are additional file path list to config files that can overwrite main config file fields
 	Imports []string `toml:"imports"`
-	// OpenTelemetry configuration
-	OpenTelemetry OpenTelemetryConfig `toml:"otel"`
 
 	StreamProcessors map[string]StreamProcessor `toml:"stream_processors"`
 }
@@ -167,14 +165,6 @@ type ProxyPlugin struct {
 	Address string `toml:"address"`
 }
 
-// OpenTelemetryConfig provides open telemetry configuration
-type OpenTelemetryConfig struct {
-	ServiceName        string  `toml:"service_name"`
-	ExporterName       string  `toml:"exporter_name"`
-	ExporterEndpoint   string  `toml:"exporter_endpoint"`
-	TraceSamplingRatio float64 `toml:"trace_sampling_ratio"`
-}
-
 // BoltConfig defines the configuration values for the bolt plugin, which is
 // loaded here, rather than back registered in the metadata package.
 type BoltConfig struct {
@@ -213,24 +203,6 @@ func (bc *BoltConfig) Validate() error {
 	}
 }
 
-const (
-	// ExporterTypeOTLP represents the open telemetry exporter OTLP
-	ExporterTypeOTLP = "otlp"
-)
-
-// Validate OpenTelemetry config
-func (cfg *OpenTelemetryConfig) Validate() error {
-	switch cfg.ExporterName {
-	case ExporterTypeOTLP:
-		if cfg.ServiceName == "" {
-			return errors.Wrapf(errdefs.ErrInvalidArgument, "missing service name in config %+v", cfg)
-		}
-		return nil
-	default:
-		return errors.Wrapf(errdefs.ErrInvalidArgument, "unsupported exporter: %+v", cfg)
-	}
-}
-
 // Decode unmarshals a plugin specific configuration by plugin id
 func (c *Config) Decode(p *plugin.Registration) (interface{}, error) {
 	id := p.URI()