Fix computersystems field (#70)

* fix graceful shutdown logic in main func, improve unmarshalling logic for different possible json responses

* update CHANGELOG and README

CHANGELOG.md

@@ -25,6 +25,7 @@ log is based on the [Keep a CHANGELOG](http://keepachangelog.com/) project.
 - Thermal Summary, Power total consumed for Cisco servers and Chassis, memory metrics for Gen9 server models [#53](https://github.com/Comcast/fishymetrics/issues/53)
 - Firmware gathering endpoint update and add device info to other HP models [#55](https://github.com/Comcast/fishymetrics/issues/55)
 - C220 drive metrics on hosts with fw < 4.0, psu metrics result and label values [#57](https://github.com/Comcast/fishymetrics/issues/57)
+- Chassis ComputerSystems field is handled improperly [#68](https://github.com/Comcast/fishymetrics/issues/68)
 
 ## Updated
 

README.md

@@ -9,7 +9,7 @@ This app can support any chassis that has the redfish API available. If one need
 
 To run it:
 
-```bash
+```
 $ ./fishymetrics --help
 usage: fishymetrics [<flags>]
 
@@ -57,7 +57,7 @@ Flags:
 
 Or set the following ENV Variables:
 
-```bash
+```
 BMC_USERNAME=<string>
 BMC_PASSWORD=<string>
 BMC_TIMEOUT=<duration> (Default: 15s)

cmd/fishymetrics/main.go

@@ -23,6 +23,7 @@ import (
 	"html/template"
 	"io"
 	logg "log"
+	"net"
 	"net/http"
 	"os"
 	"os/signal"
@@ -319,17 +320,27 @@ func main() {
 		Handler: loggingHandler(mux),
 	}
 
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
-
-		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
-			log.Error("starting "+app+" service failed", zap.Error(err))
-		}
-	}()
-
 	signals := make(chan os.Signal, 1)
 	signal.Notify(signals, os.Interrupt, syscall.SIGTERM, syscall.SIGHUP)
+
+	listener, err := net.Listen("tcp4", ":"+*exporterPort)
+	if err != nil {
+		log.Error("starting "+app+" service failed", zap.Error(err))
+		signals <- syscall.SIGTERM
+	} else {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+
+			if err := srv.Serve(listener); err != nil && err != http.ErrServerClosed {
+				log.Error("http server received an error", zap.Error(err))
+				signals <- syscall.SIGTERM
+			}
+		}()
+
+		log.Info("started " + app + " service")
+	}
+
 	wg.Add(1)
 	go func() {
 		defer wg.Done()
@@ -346,8 +357,6 @@ func main() {
 		doneRenew <- true
 	}()
 
-	log.Info("started " + app + " service")
-
 	wg.Wait()
 }
 

oem/chassis.go

@@ -17,7 +17,6 @@
 package oem
 
 import (
-	"bytes"
 	"encoding/json"
 )
 
@@ -62,25 +61,36 @@ type LinksWrapper struct {
 
 func (w *LinksWrapper) UnmarshalJSON(data []byte) error {
 	// because of a change in output between firmware versions we need to account for this
-	if bytes.Compare([]byte("[{"), data[0:2]) == 0 {
-		var linksTmp []struct {
-			URL  string `json:"@odata.id,omitempty"`
-			HRef string `json:"href,omitempty"`
-		}
-		err := json.Unmarshal(data, &linksTmp)
-		if len(linksTmp) > 0 {
-			for _, l := range linksTmp {
+	// try to unmarshal as a slice of structs
+	// [
+	//   {
+	//     "@odata.id": "/redfish/v1/Systems/XXXX"
+	//   }
+	// ]
+	var links []struct {
+		URL  string `json:"@odata.id,omitempty"`
+		HRef string `json:"href,omitempty"`
+	}
+	err := json.Unmarshal(data, &links)
+	if err == nil {
+		if len(links) > 0 {
+			for _, l := range links {
 				if l.URL != "" {
 					w.LinksURLSlice = append(w.LinksURLSlice, l.URL)
 				} else {
 					w.LinksURLSlice = append(w.LinksURLSlice, l.HRef)
 				}
 			}
-			return nil
 		}
-		return err
+	} else {
+		// try to unmarshal as a slice of strings
+		// [
+		//   "/redfish/v1/Systems/XXXX"
+		// ]
+		return json.Unmarshal(data, &w.LinksURLSlice)
 	}
-	return json.Unmarshal(data, &w.LinksURLSlice)
+
+	return nil
 }
 
 type ChassisStorageBattery struct {

oem/drive.go

@@ -17,7 +17,6 @@
 package oem
 
 import (
-	"bytes"
 	"encoding/json"
 )
 
@@ -81,22 +80,36 @@ type LocationWrapper struct {
 
 func (w *LocationWrapper) UnmarshalJSON(data []byte) error {
 	// because of a change in output between firmware versions we need to account for this
-	if bytes.Compare([]byte("[{"), data[0:2]) == 0 {
-		var locTmp []struct {
-			Loc string `json:"Info,omitempty"`
-		}
-		err := json.Unmarshal(data, &locTmp)
-		if len(locTmp) > 0 {
-			for _, l := range locTmp {
+	// try to unmarshal as a slice of structs
+	// [
+	//   {
+	//     "Info": "location data"
+	//   }
+	// ]
+	var loc []struct {
+		Loc string `json:"Info,omitempty"`
+	}
+	err := json.Unmarshal(data, &loc)
+	if err == nil {
+		if len(loc) > 0 {
+			for _, l := range loc {
 				if l.Loc != "" {
 					w.Location = l.Loc
 				}
 			}
-			return nil
 		}
-		return err
+	} else {
+		// try to unmarshal as a string
+		// {
+		//   ...
+		//   "Location": "location data"
+		//   ...
+		// }
+		return json.Unmarshal(data, &w.Location)
 	}
-	return json.Unmarshal(data, &w.Location)
+
+	return nil
+
 }
 
 // GenericDrive is used to iterate over differing drive endpoints

oem/manager.go

@@ -17,7 +17,6 @@
 package oem
 
 import (
-	"bytes"
 	"encoding/json"
 )
 
@@ -45,26 +44,37 @@ type ServerManagerURLWrapper struct {
 }
 
 func (w *ServerManagerURLWrapper) UnmarshalJSON(data []byte) error {
-	// because of a change in output betwen c220 firmware versions we need to account for this
-	if bytes.Compare([]byte("[{"), data[0:2]) == 0 {
-		var serMgrTmp []struct {
-			UrlLinks string `json:"@odata.id,omitempty"`
-			Urllinks string `json:"href,omitempty"`
-		}
-		err := json.Unmarshal(data, &serMgrTmp)
-		if len(serMgrTmp) > 0 {
-			s := make([]string, 0)
-			if serMgrTmp[0].UrlLinks != "" {
-				s = append(s, serMgrTmp[0].UrlLinks)
-			} else {
-				s = append(s, serMgrTmp[0].Urllinks)
+	// because of a change in output between firmware versions we need to account for this
+	// try to unmarshal as a slice of structs
+	// [
+	//   {
+	//     "@odata.id": "/redfish/v1/Systems/XXXX"
+	//   }
+	// ]
+	var svrMgr []struct {
+		URL  string `json:"@odata.id,omitempty"`
+		HRef string `json:"href,omitempty"`
+	}
+	err := json.Unmarshal(data, &svrMgr)
+	if err == nil {
+		if len(svrMgr) > 0 {
+			for _, l := range svrMgr {
+				if l.URL != "" {
+					w.ServerManagerURLSlice = append(w.ServerManagerURLSlice, l.URL)
+				} else {
+					w.ServerManagerURLSlice = append(w.ServerManagerURLSlice, l.HRef)
+				}
 			}
-			w.ServerManagerURLSlice = s
-			return nil
 		}
-		return err
+	} else {
+		// try to unmarshal as a slice of strings
+		// [
+		//   "/redfish/v1/Systems/XXXX"
+		// ]
+		return json.Unmarshal(data, &w.ServerManagerURLSlice)
 	}
-	return json.Unmarshal(data, &w.ServerManagerURLSlice)
+
+	return nil
 }
 
 type IloSelfTest struct {

oem/power.go

@@ -17,7 +17,6 @@
 package oem
 
 import (
-	"bytes"
 	"encoding/json"
 )
 
@@ -50,19 +49,19 @@ type PowerControlWrapper struct {
 }
 
 func (w *PowerControlWrapper) UnmarshalJSON(data []byte) error {
-	// because of a change in output betwen firmware versions we need to account for this
-	if bytes.Compare([]byte("{"), data[0:1]) == 0 {
-		var powCtlSlice PowerControl
-		err := json.Unmarshal(data, &powCtlSlice)
-		if err != nil {
-			return err
-		}
+	// because of a change in output between firmware versions we need to account for this
+	// PowerControl can either be []PowerControl or a singular PowerControl
+	var powCtl PowerControl
+	err := json.Unmarshal(data, &powCtl)
+	if err == nil {
 		s := make([]PowerControl, 0)
-		s = append(s, powCtlSlice)
+		s = append(s, powCtl)
 		w.PowerControl = s
-		return nil
+	} else {
+		return json.Unmarshal(data, &w.PowerControl)
 	}
-	return json.Unmarshal(data, &w.PowerControl)
+
+	return nil
 }
 
 // PowerMetric contains avg/min/max power metadata

oem/storage_ctrl.go

@@ -17,7 +17,6 @@
 package oem
 
 import (
-	"bytes"
 	"encoding/json"
 )
 
@@ -48,19 +47,19 @@ type StorageControllerWrapper struct {
 }
 
 func (w *StorageControllerWrapper) UnmarshalJSON(data []byte) error {
-	// because of a change in output betwen c220 firmware versions we need to account for this
-	if bytes.Compare([]byte("{"), data[0:1]) == 0 {
-		var storCtlSlice StorageController
-		err := json.Unmarshal(data, &storCtlSlice)
-		if err != nil {
-			return err
-		}
-		s := make([]StorageController, 0)
-		s = append(s, storCtlSlice)
-		w.StorageController = s
-		return nil
+	// because of a change in output between firmware versions we need to account for this
+	// StorageController can either be []StorageController or a singular StorageController
+	var storCtl StorageController
+	err := json.Unmarshal(data, &storCtl)
+	if err == nil {
+		sc := make([]StorageController, 0)
+		sc = append(sc, storCtl)
+		w.StorageController = sc
+	} else {
+		return json.Unmarshal(data, &w.StorageController)
 	}
-	return json.Unmarshal(data, &w.StorageController)
+
+	return nil
 }
 
 type Drive struct {