Add MapMonitoredResource field to Log config. (#826)

* Add MapMonitoredResource field to Log config.

* Update exporter/collector/config.go

Co-authored-by: David Ashpole <dashpole@google.com>
Signed-off-by: aglipska <107988284+aglipska@users.noreply.github.com>

* Fix lint and test problems.

---------

Signed-off-by: aglipska <107988284+aglipska@users.noreply.github.com>
Co-authored-by: David Ashpole <dashpole@google.com>

exporter/collector/config.go

@@ -168,6 +168,11 @@ type ResourceFilter struct {
 }
 
 type LogConfig struct {
+	// MapMonitoredResource is not exposed as an option in the configuration, but
+	// can be used by other exporters to extend the functionality of this
+	// exporter. It allows overriding the function used to map otel resource to
+	// monitored resource.
+	MapMonitoredResource func(pcommon.Resource) *monitoredrespb.MonitoredResource
 	// DefaultLogName sets the fallback log name to use when one isn't explicitly set
 	// for a log entry. If unset, logs without a log name will raise an error.
 	DefaultLogName string `mapstructure:"default_log_name"`
@@ -194,6 +199,7 @@ func DefaultConfig() Config {
 		UserAgent: "opentelemetry-collector-contrib {{version}}",
 		LogConfig: LogConfig{
 			ServiceResourceLabels: true,
+			MapMonitoredResource:  defaultResourceToLoggingMonitoredResource,
 		},
 		MetricConfig: MetricConfig{
 			KnownDomains:                     domains,

exporter/collector/integrationtest/config/config_test.go

@@ -89,6 +89,7 @@ func TestLoadConfig(t *testing.T) {
 func sanitize(cfg *testExporterConfig) *testExporterConfig {
 	cfg.Config.MetricConfig.MapMonitoredResource = nil
 	cfg.Config.MetricConfig.GetMetricName = nil
+	cfg.Config.LogConfig.MapMonitoredResource = nil
 	return cfg
 }
 

exporter/collector/logs.go

@@ -278,7 +278,7 @@ func (l logMapper) createEntries(ld plog.Logs) (map[string][]*logpb.LogEntry, er
 	entries := make(map[string][]*logpb.LogEntry)
 	for i := 0; i < ld.ResourceLogs().Len(); i++ {
 		rl := ld.ResourceLogs().At(i)
-		mr := defaultResourceToLoggingMonitoredResource(rl.Resource())
+		mr := l.cfg.LogConfig.MapMonitoredResource(rl.Resource())
 		extraResourceLabels := attributesToUnsanitizedLabels(filterAttributes(rl.Resource().Attributes(), l.cfg.LogConfig.ServiceResourceLabels, l.cfg.LogConfig.ResourceFilters))
 		projectID := l.cfg.ProjectID
 		// override project ID with gcp.project.id, if present