[pkg/datadog] add IgnoreMissingDatadogFields config flag for consumpt… (#40226)

…ion by datadog-agent connector

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description

IgnoreMissingDatadogFields is needed in datadog-agent fork of
datadogconnector. In `opentelemetry-collector-contrib`, for now, using
this flag will throw an error. In an upcoming datadog-agent PR, we will
use this flag to control datadogconnector logic in datadog-agent's
`stats.OTLPTracesToConcentratorInputsWithObfuscation`. Once that is
merged, a follow up PR in `opentelemetry-collector-contrib` will bump
the datadog-agent version and enable these changes, at which point we'll
allow IgnoreMissingDatadogFields to be set.

<!-- Issue number (e.g. #1234) or full URL to issue, if applicable. -->
#### Link to tracking issue
Fixes

<!--Describe what testing was performed and which tests were added.-->
#### Testing

<!--Describe the documentation added.-->
#### Documentation

<!--Please delete paragraphs that you did not use before submitting.-->

Author: IbraheemA

connector/datadogconnector/config.go

@@ -4,6 +4,8 @@
 package datadogconnector // import "github.com/open-telemetry/opentelemetry-collector-contrib/connector/datadogconnector"
 
 import (
+	"errors"
+
 	"go.opentelemetry.io/collector/component"
 
 	datadogconfig "github.com/open-telemetry/opentelemetry-collector-contrib/pkg/datadog/config"
@@ -21,5 +23,8 @@ type Config struct {
 
 // Validate checks if the configuration is valid
 func (c *Config) Validate() error {
+	if c.Traces.IgnoreMissingDatadogFields {
+		return errors.New("ignore_missing_datadog_fields is not yet supported in the connector")
+	}
 	return c.Traces.Validate()
 }

connector/datadogconnector/config_test.go

@@ -99,6 +99,15 @@ func TestValidate(t *testing.T) {
 			},
 			err: "bucket interval must be non-negative",
 		},
+		{
+			name: "With ignore_missing_datadog_fields",
+			cfg: &Config{
+				Traces: datadogconfig.TracesConnectorConfig{
+					IgnoreMissingDatadogFields: true,
+				},
+			},
+			err: "ignore_missing_datadog_fields is not yet supported in the connector",
+		},
 	}
 	for _, testInstance := range tests {
 		t.Run(testInstance.name, func(t *testing.T) {

pkg/datadog/config/traces.go

@@ -150,6 +150,13 @@ type TracesConnectorConfig struct {
 	// If you are concerned about the metric volume generated by the Datadog connector and the resulting networking egress, try increasing bucket_interval.
 	// Default is 10s if unset.
 	BucketInterval time.Duration `mapstructure:"bucket_interval"`
+
+	// IgnoreMissingDatadogFields specifies whether we should recompute DD span fields if the corresponding "datadog."
+	// namespaced span attributes are missing. If it is false (default), we will use the incoming "datadog." namespaced
+	// OTLP span attributes to construct the DD span, and if they are missing, we will recompute them from the other
+	// OTLP semantic convention attributes. If it is true, we will only populate a field if its associated "datadog."
+	// OTLP span attribute exists, otherwise we will leave it empty.
+	IgnoreMissingDatadogFields bool `mapstructure:"ignore_missing_datadog_fields"`
 }
 
 func (c *TracesConnectorConfig) Validate() error {