cloud/bmaas/bmdb: implement BMDB client metrics

This implements some basic BMDB metrics exported by any client code
using the BMDB.

It also enables their use in the Shepherd and BMSRV.

Change-Id: I1d5e82fd2c34a7bfd42f37fad540d69f7b23f347
Reviewed-on: https://review.monogon.dev/c/monogon/+/1600
Tested-by: Jenkins CI
Reviewed-by: Tim Windelschmidt <tim@monogon.tech>
diff --git a/cloud/shepherd/equinix/manager/updater.go b/cloud/shepherd/equinix/manager/updater.go
index 6c00b97..dd8c6ff 100644
--- a/cloud/shepherd/equinix/manager/updater.go
+++ b/cloud/shepherd/equinix/manager/updater.go
@@ -12,6 +12,7 @@
 	"k8s.io/klog/v2"
 
 	"source.monogon.dev/cloud/bmaas/bmdb"
+	"source.monogon.dev/cloud/bmaas/bmdb/metrics"
 	"source.monogon.dev/cloud/bmaas/bmdb/model"
 	"source.monogon.dev/cloud/lib/sinbin"
 	ecl "source.monogon.dev/cloud/shepherd/equinix/wrapngo"
@@ -57,7 +58,7 @@
 
 	for {
 		if sess == nil {
-			sess, err = conn.StartSession(ctx)
+			sess, err = conn.StartSession(ctx, bmdb.SessionOption{Processor: metrics.ProcessorShepherdUpdater})
 			if err != nil {
 				return fmt.Errorf("could not start BMDB session: %w", err)
 			}