succd: Export all process values as prometheus metrics

For more detailed monitoring, let's export all process values that are
exposed to the web API as prometheus metrics.

succbone/succd/http.go

@@ -163,16 +163,60 @@ func (s *webServer) viewStream(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+func boolToFloat(b bool) float32 {
+	if b {
+		return 1.0
+	} else {
+		return 0.0
+	}
+}
+
 // httpMetrics serves minimalistic Prometheus-compatible metrics.
 func (s *webServer) viewMetrics(w http.ResponseWriter, r *http.Request) {
 	// TODO(q3k): also serve Go stuff using the actual Prometheus metrics client
 	// library.
 	// TODO(q3k): serve the rest of the data model
 	state := s.d.snapshot()
-	mbar := state.piraniMbar100.mbar
+
+	// sem_pressure_mbar is meant to represent the fused pressure value
+	// from all data sources once we have more vacuum sensors in the
+	// system.  sem_pirani_mbar is just the reading from the pirani gauge.
 	fmt.Fprintf(w, "# HELP sem_pressure_mbar Pressure in the SEM chamber, in millibar\n")
 	fmt.Fprintf(w, "# TYPE sem_pressure_mbar gauge\n")
-	fmt.Fprintf(w, "sem_pressure_mbar %f\n", mbar)
+	fmt.Fprintf(w, "sem_pressure_mbar %f\n", state.piraniMbar100.mbar)
+
+	fmt.Fprintf(w, "# HELP sem_pirani_mbar Pressure reading by the Pirani gauge, in millibar\n")
+	fmt.Fprintf(w, "# TYPE sem_pirani_mbar gauge\n")
+	fmt.Fprintf(w, "sem_pirani_mbar %f\n", state.piraniMbar100.mbar)
+
+	fmt.Fprintf(w, "# HELP sem_pirani_volts Voltage output from the Pirani gauge, in volts\n")
+	fmt.Fprintf(w, "# TYPE sem_pirani_volts gauge\n")
+	fmt.Fprintf(w, "sem_pirani_volts %f\n", state.piraniVolts100.avg)
+
+	fmt.Fprintf(w, "# HELP sem_pirani_failsafe_active Whether pirani gauge failsafe mode is active (boolean)\n")
+	fmt.Fprintf(w, "# TYPE sem_pirani_failsafe_active gauge\n")
+	fmt.Fprintf(w, "sem_pirani_failsafe_active %f\n", boolToFloat(state.safety.failsafe))
+
+	fmt.Fprintf(w, "# HELP sem_dp_lockout_active Whether diffusion pump lockout is active (boolean)\n")
+	fmt.Fprintf(w, "# TYPE sem_dp_lockout_active gauge\n")
+	fmt.Fprintf(w, "sem_dp_lockout_active %f\n", boolToFloat(state.safety.highPressure))
+
+	fmt.Fprintf(w, "# HELP sem_pump_diffusion_running Whether the diffusion pump is running (boolean)\n")
+	fmt.Fprintf(w, "# TYPE sem_pump_diffusion_running gauge\n")
+	fmt.Fprintf(w, "sem_pump_diffusion_running %f\n", boolToFloat(state.dpOn))
+
+	fmt.Fprintf(w, "# HELP sem_pump_roughing_running Whether the roughing pump is running (boolean)\n")
+	fmt.Fprintf(w, "# TYPE sem_pump_roughing_running gauge\n")
+	fmt.Fprintf(w, "sem_pump_roughing_running %f\n", boolToFloat(state.rpOn))
+
+	rough, high := state.vacuumStatus()
+	fmt.Fprintf(w, "# HELP sem_vacuum_rough_reached Whether a rough vacuum has been reached (boolean)\n")
+	fmt.Fprintf(w, "# TYPE sem_vacuum_rough_reached gauge\n")
+	fmt.Fprintf(w, "sem_vacuum_rough_reached %f\n", boolToFloat(rough))
+
+	fmt.Fprintf(w, "# HELP sem_vacuum_high_reached Whether a high vacuum has been reached (boolean)\n")
+	fmt.Fprintf(w, "# TYPE sem_vacuum_high_reached gauge\n")
+	fmt.Fprintf(w, "sem_vacuum_high_reached %f\n", boolToFloat(high))
 }
 
 func (s *webServer) viewRoughingPumpEnable(w http.ResponseWriter, r *http.Request) {