Add prometheus submodule.

This submodule simplifies registering FastBreaker metrics to prometheus.

Author: Eduard Llull

go.work

@@ -0,0 +1,6 @@
+go 1.20
+
+use (
+	.
+	./prometheus
+)

go.work.sum

@@ -0,0 +1,4 @@
+github.com/google/go-cmp v0.5.8 h1:e6P7q2lk1O+qJJb4BtCQXlK8vWEO8V1ZeuEdJNOqZyg=
+golang.org/x/exp v0.0.0-20200224162631-6cc2880d07d6 h1:QE6XYQK6naiK1EPAe1g/ILLxN5RBoH5xkJk3CqlMI/Y=
+golang.org/x/sys v0.1.0 h1:kunALQeHf1/185U1i0GOB/fy1IPRDDpuoOOqRReG57U=
+golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

prometheus/go.mod

@@ -0,0 +1,20 @@
+module github.com/bluekiri/fastbreaker/prometheus
+
+go 1.20
+
+require (
+	github.com/bluekiri/fastbreaker v1.0.1
+	github.com/prometheus/client_golang v1.14.0
+	github.com/prometheus/client_model v0.3.0
+)
+
+require (
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.1.2 // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
+	github.com/prometheus/common v0.37.0 // indirect
+	github.com/prometheus/procfs v0.8.0 // indirect
+	golang.org/x/sys v0.1.0 // indirect
+	google.golang.org/protobuf v1.28.1 // indirect
+)