Update README, set timeout as default 10 in configuration sample

.gitignore

@@ -1,4 +1,4 @@
 nodegopher
 config.yaml*
-!config.yaml.sample
+!config.sample.yml
 main.go.*

README.md

@@ -12,16 +12,20 @@ It gets time range values from Grafana, so it can relay them to prometheus if yo
 see config.yaml.sample  
 
 ## Grafana datasource
-Successfully tested with yesoreyeram-infinity-datasource datasource  
+Successfully tested with [yesoreyeram-infinity-datasource](https://github.com/grafana/grafana-infinity-datasource) datasource  
 
 Create an infinity query, name it "Edges". Type "JSON", Parser "Backend", Source "URL", Format "Table", Method "GET"  
 URL: "http://my-nodegopher-host:8080/graph1/edges?from=$__from&to=$__to&interval=$__interval"  
 
+![Edges configuration](https://git.nosd.in/yo/nodegopher/raw/branch/main/docs/nodegopher_grafana_edges.png "Edges configuration")
+
 Create a second infinity query named "Nodes", same config,  
 URL: "http://my-nodegopher-host:8080/graph1/nodes?from=$__from&to=$__to&interval=$__interval"  
 
 switch to visualization type "NodeGraph", and voila
 
+![NodeGraph sample](https://git.nosd.in/yo/nodegopher/raw/branch/main/docs/nodegopher_sample.png "NodeGraph sample")
+
 ## Instance management
 ### Reload configuration
 You can reload configuration file when the API is running, with either sending a signal, or make a POST request.  
@@ -36,3 +40,9 @@ Sending POST on /reload :
 curl -XPOST http://my-nodegopher-host:8080/reload
 {"message":"configuration successfully reloaded"}
 ```
+
+Reloading a badly formated configuration will produce an error and keep the old configuration running.  
+```
+% curl -XPOST 127.1:8080/reload
+{"error":"Unable to load new configuration, keeping old one. See logs."}
+```

config.sample.yaml

@@ -1,43 +1,50 @@
+# Formatting metrics in main & secondarystat. Supported: "english", "french", "german", "ukrainian", "chinese", "arabic". Default is english.
+language: 'english'
+
 # datasource describe a way to get prometheus metrics.
 # Properties :
 # - name: name of the query. To be used in edges or nodes mainstatquery or secondarystatquery. Result will be output in mainstat, or secondarystat.
 # - address: the address of prometheus.
 # - query: prometheus query. Same as typed in prometheus graph page.
 # - type: type of query. "query" will get instant value, "query_range" will get all samples for the grafana period. Result will be averaged.
-# - timeout: query timeout in seconds.
+# - timeout: query timeout in seconds. default is 10.
 datasources:
   - name: prom_samples_per_sec
     type: query
     address: 'http://prometheus.local.lan:9090'
     query: 'rate(prometheus_tsdb_head_samples_appended_total{type="float"}[10m])'
-    timeout: 10
+    timeout: 15
   - name: node_cpu_metric
     # Simple query, return an instant metric
     type: query
     address: 'http://prometheus.local.lan:9090'
     query: 'sum(rate(node_cpu_seconds_total{instance="router01.local.lan:9100",job="node",mode!~"idle"}[30s]))*100'
-    timeout: 10
+  - name: node_cpu_metric_over_80
+    type: query
+    address: 'http://prometheus.local.lan:9090'
+    # Return 1 if cpu rate > 80%
+    query: '(sum(rate(node_cpu_seconds_total{instance="router01.local.lan:9100",job="node",mode!~"idle"}[30s]))*100) > bool 80'
   - name: router01_net_down_rate
     # Range query. Return all metrics from a time range. Result will be averaged from these metrics. Time range will be provided by Grafana.
     type: query_range
     address: 'http://prometheus.local.lan:9090'
     query: 'rate(node_network_receive_bytes_total{device="igb0", instance="router01.local.lan:9100", job="node"}[30s])'
-    timeout: 10
   - name: router01_net_up_rate
     type: query_range
     address: 'http://prometheus.local.lan:9090'
     query: 'rate(node_network_transmit_bytes_total{device="igb0", instance="router01.local.lan:9100", job="node"}[30s])'
-    timeout: 10
   - name: router01_lan_down_rate
     type: query_range
     address: 'http://prometheus.local.lan:9090'
     query: 'rate(node_network_receive_bytes_total{device="ix3", instance="router01.local.lan:9100", job="node"}[30s])'
-    timeout: 10
   - name: router01_lan_up_rate
     type: query_range
     address: 'http://prometheus.local.lan:9090'
     query: 'rate(node_network_transmit_bytes_total{device="ix3", instance="router01.local.lan:9100", job="node"}[30s])'
-    timeout: 10
+  - name: router01_net_down_rate_perten
+    type: query
+    address: 'http://prometheus.local.lan:9090'
+    query: 'rate(node_network_receive_bytes_total{device="igb0", instance="router01.local.lan:9100", job="node"}[30s])/62500000*10'
 
 # graphs identifies context for a nodegraph. You can have many contexts, and your grafana query will mention this context name.
 #  For this example named "internet", grafana URL will be :
@@ -47,16 +54,25 @@ datasources:
 # - name: name of the context
 # - nodes: list of nodegraph nodes
 # - edges: list of nodegraph edges
+#
+# Dynamic fields :
+#  nodes:
+#    - mainstat : use mainstatquery and mainstatformat. mainstatquery should return a metric, mainstatformat is a printf format specifier.
+#    - secondarystat : use secondarystatquery and secondarystatformat. same as mainstat(query|format).
+#    - hightlighted : use highlightedquery. if result return > 0, item will be highligthed.
+#  edges:
+#    - same list as nodes.
+#    - thickness: use thicknessquery.
 graphs:
   - name: internet
     nodes:
-    - name: internet
-      id: internet
-      title: "internet"
-      subtitle: "The internets"
-      color: "grey"
-      # icons come from https://developers.grafana.com/ui/latest/index.html?path=/story/docs-overview-icon--icons-overview
-      icon: "globe"
+    - name: host01
+      id: host01
+      title: host01
+      subtitle: "A workstation"
+      color: "green"
+      # icon come from https://developers.grafana.com/ui/latest/index.html?path=/story/docs-overview-icon--icons-overview
+      icon: "user"
     - name: router01
       id: router01
       title: router01
@@ -65,39 +81,43 @@ graphs:
       mainstatquery: '{{ node_cpu_metric }}'
       # Use %% if you want to display '%' in you metric label
       mainstatformat: '%0.2f%% cpu'
-    - name: host01
-      id: host01
-      title: host01
-      subtitle: "A workstation"
-      color: "green"
-      icon: "user"
+      # highlight router if cpu > 80%
+      highlightedquery: '{{ node_cpu_metric_over_80 }}'
+    - name: internet
+      id: internet
+      title: "internet"
+      subtitle: "The internets"
+      color: "grey"
+      icon: "globe"
     edges:
     - id: edge0
-      source: internet
-      target: router01
-      mainstatquery: '{{ router01_net_up_rate }}'
-      mainstatformat: 'up %0.0f bps'
-      secondarystatquery: '{{ router01_net_down_rate }}'
-      secondarystatformat: 'down %0.0f bps'
-    - id: edge1
-      source: router01
-      target: internet
-      mainstatquery: '{{ router01_net_up_rate }}'
-      mainstatformat: 'up %0.0f bps'
-      secondarystatquery: '{{ router01_net_down_rate }}'
-      secondarystatformat: 'down %0.0f bps'
-    - id: edge2
-      source: router01
-      target: host01
-      mainstatquery: '{{ router01_lan_down_rate }}'
-      mainstatformat: 'up %0.0f bps'
-      secondarystatquery: '{{ router01_lan_up_rate }}'
-      secondarystatformat: 'down %0.0f bps'
-    - id: edge3
       source: host01
       target: router01
       mainstatquery: '{{ router01_lan_down_rate }}'
-      mainstatformat: 'up %0.0f bps'
+      mainstatformat: 'up %0.0f Bps'
       secondarystatquery: '{{ router01_lan_up_rate }}'
-      secondarystatformat: 'down %0.0f bps'
+      secondarystatformat: 'down %0.0f Bps'
+    - id: edge1
+      source: router01
+      target: host01
+      mainstatquery: '{{ router01_lan_down_rate }}'
+      mainstatformat: 'up %0.0f Bps'
+      secondarystatquery: '{{ router01_lan_up_rate }}'
+      secondarystatformat: 'down %0.0f Bps'
+      thicknessquery: '{{ router01_net_down_rate_perten }}'
+    - id: edge2
+      source: router01
+      target: internet
+      mainstatquery: '{{ router01_net_up_rate }}'
+      mainstatformat: 'up %0.0f Bps'
+      secondarystatquery: '{{ router01_net_down_rate }}'
+      secondarystatformat: 'down %0.0f Bps'
+    - id: edge3
+      source: internet
+      target: router01
+      mainstatquery: '{{ router01_net_up_rate }}'
+      mainstatformat: 'up %0.0f Bps'
+      secondarystatquery: '{{ router01_net_down_rate }}'
+      secondarystatformat: 'down %0.0f Bps'
+      thicknessquery: '{{ router01_net_down_rate_perten }}'
 

edges.go

@@ -20,7 +20,9 @@ type Edge struct {
 	SecondaryStatFormat string  `yaml:"secondarystatformat,omitempty" json:"secondarystatformat,omitempty"`
 	Color               string  `yaml:"color,omitempty" json:"color,omitempty"`
 	Thickness           int     `yaml:"thickness,omitempty" json:"thickness,omitempty"`
-	HighLighted         bool    `yaml:"highlighted,omitempty" json:"hightlighted,omitempty"`
+	ThicknessQuery      string  `yaml:"thicknessquery,omitempty" json:"thicknessquery,omitempty"`
+	Highlighted         bool    `yaml:"highlighted,omitempty" json:"hightlighted,omitempty"`
+	HighlightedQuery    string  `yaml:"highlightedquery,omitempty" json:"highlightedquery,omitempty"`
 	StrokeDashArray     float32 `yaml:"strokeDasharray,omitempty" json:"strokeDasharray,omitempty"`
 }
 
@@ -56,10 +58,26 @@ func (e *Edge) SetMainStat(stat string) {
 	e.MainStat = fmt.Sprintf("%s", stat)
 }
 
+func (e *Edge) GetThicknessQuery() string {
+	return e.ThicknessQuery
+}
+
+func (e *Edge) SetThickness(thickness float64) {
+	e.Thickness = int(thickness)
+}
+
 func (e *Edge) SetSecondaryStat(stat string) {
 	e.SecondaryStat = fmt.Sprintf("%s", stat)
 }
 
+func (e *Edge) GetHighlightedQuery() string {
+	return e.HighlightedQuery
+}
+
+func (e *Edge) SetHighlighted(highlighted bool) {
+	e.Highlighted = highlighted
+}
+
 // Custom marshaler to not send (main|secondary)statquery
 func (e Edge) MarshalJSON() ([]byte, error) {
 	jsonRes := `{"id":"` + e.Id + `","source":"` + e.Source + `","target":"` + e.Target + `"`
@@ -75,7 +93,7 @@ func (e Edge) MarshalJSON() ([]byte, error) {
 	if e.Thickness > 0 {
 		jsonRes += `,"thickness":` + strconv.Itoa(e.Thickness)
 	}
-	if e.HighLighted {
+	if e.Highlighted {
 		jsonRes += `,"highlighted":true`
 	}
 	// TODO : e.StrokeDashArray

main.go

@@ -18,20 +18,25 @@ import (
 	"syscall"
 	"net/http"
 	"os/signal"
-	
+
 	"gopkg.in/yaml.v2"
 	"github.com/spf13/viper"
 	"github.com/gin-gonic/gin"
 	"github.com/fsnotify/fsnotify"
 	log "github.com/sirupsen/logrus"
-	
+
+	"golang.org/x/text/language"
+	"golang.org/x/text/message"
+
 	"github.com/prometheus/common/model"
 	"github.com/prometheus/client_golang/api"
 	v1 "github.com/prometheus/client_golang/api/prometheus/v1"
 )
 
 const (
-	gVersion = "0.2.1"
+	gVersion = "0.2.5"
+	// Default datasource timeout is 10 seconds
+	gDefaultDSTimeout = 10
 )
 
 type PromDataSourceConfig struct {
@@ -57,7 +62,11 @@ type Item interface {
 	GetSecondaryStat()       string
 	GetSecondaryStatQuery()  string
 	GetSecondaryStatFormat() string
-	SetSecondaryStat(string) 
+	SetSecondaryStat(string)
+	GetThicknessQuery()      string
+	SetThickness(float64)
+	GetHighlightedQuery()    string
+	SetHighlighted(bool)
 }
 
 // Query arguments. Based on grafana internal variables.
@@ -75,6 +84,7 @@ type MyRange struct {
 }
 
 var (
+	gPrinter *message.Printer
 	gDebug bool
 	gGraphs []Graph
 	gDataSources []PromDataSourceConfig
@@ -112,13 +122,13 @@ func (d *PromDataSourceConfig) GetData(timeRange *MyRange) (float64, error) {
 		result, warnings, err = v1api.QueryRange(ctx, d.Query, rng, v1.WithTimeout(time.Duration(d.Timeout)*time.Second))
 	}
 	if err != nil {
-		log.Errorf("DataSourceConfig.GetData: Error querying Prometheus: %v\n", err)
+		log.Errorf("DataSourceConfig.GetData: Error querying Prometheus: %v. Query is: %s\n", err, d.Query)
 		return 0.0, err
 	}
 	if len(warnings) > 0 {
 		log.Warningf("DataSourceConfig.GetData: Warnings: %v\n", warnings)
 	}
-	log.Debugf("DataSourceConfig.GetData: Result: %v\n", result)
+	//log.Debugf("DataSourceConfig.GetData: Result: %v\n", result)
 
 	switch {
 		case result.Type() == model.ValScalar:
@@ -163,8 +173,9 @@ func (g Graph) BuildMetrics(items *[]Item, timeRange *MyRange) (*[]Item, error)
 	// Acquire Read Lock. This won't prevent other queries being answered, but reloadConfig WLock will have to wait until we finish
 	gCfgMutex.RLock()
 	defer gCfgMutex.RUnlock()
-	
+
 	for _, item := range *items {
+		// Handle mainStat
 		if len(item.GetMainStatQuery()) > 0 {
 			log.Debugf("Item %s have mainstatquery: %s\n", item.GetId(), item.GetMainStatQuery())
 			r := gDSVarCompRegex.FindStringSubmatch(item.GetMainStatQuery())
@@ -185,12 +196,13 @@ func (g Graph) BuildMetrics(items *[]Item, timeRange *MyRange) (*[]Item, error)
 				if len(format) == 0 {
 					format = "%f"
 				}
-				log.Debugf("buildMetrics: Replace %s mainstat with %s\n", item.GetId(), fmt.Sprintf(format, value))
-				item.SetMainStat(fmt.Sprintf(format, value))
+				log.Debugf("buildMetrics: Replace %s mainstat with %s\n", item.GetId(), gPrinter.Sprintf(format, value))
+				item.SetMainStat(gPrinter.Sprintf(format, value))
 			} else {
 				log.Errorf("buildMetrics: Item %s mainstatquery unparseable: %s\n", item.GetId(), item.GetMainStatQuery())
 			}
 		}
+		// Handle secondaryStat
 		if len(item.GetSecondaryStatQuery()) > 0 {
 			log.Debugf("Item %s have mainstatquery: %s\n", item.GetId(), item.GetSecondaryStatQuery())
 			r := gDSVarCompRegex.FindStringSubmatch(item.GetSecondaryStatQuery())
@@ -211,12 +223,66 @@ func (g Graph) BuildMetrics(items *[]Item, timeRange *MyRange) (*[]Item, error)
 				if len(format) == 0 {
 					format = "%f"
 				}
-				log.Debugf("buildMetrics: Replace %s secondarystat with %s\n", item.GetId(), fmt.Sprintf(format, value))
-				item.SetSecondaryStat(fmt.Sprintf(format, value))
+				log.Debugf("buildMetrics: Replace %s secondarystat with %s\n", item.GetId(), gPrinter.Sprintf(format, value))
+				item.SetSecondaryStat(gPrinter.Sprintf(format, value))
 			} else {
 				log.Errorf("buildMetrics: Item %s secondarystatquery unparseable: %s\n", item.GetId(), item.GetSecondaryStatQuery())
 			}
 		}
+		// Handle highlighted
+		if len(item.GetHighlightedQuery()) > 0 {
+			log.Debugf("buildMetrics: Item %s have highlightedquery: %s\n", item.GetId(), item.GetHighlightedQuery())
+			r := gDSVarCompRegex.FindStringSubmatch(item.GetHighlightedQuery())
+			if len(r) > 1 {
+				var value float64
+				dsname := strings.TrimSpace(r[1])
+				log.Debugf("buildMetrics: datasource from highlightedquery : %s\n", dsname)
+				for _, d := range gDataSources {
+					if strings.EqualFold(d.Name, dsname) {
+						value, err = d.GetData(timeRange)
+						if err != nil {
+							return nil, err
+						}
+						break
+					}
+				}
+				highlight := false
+				if value == 0 {
+					highlight = false
+				} else {
+					highlight = true
+				}
+				log.Debugf("buildMetrics: Replace %s highlighted with %t\n", item.GetId(), highlight)
+				item.SetHighlighted(highlight)
+			} else {
+				log.Errorf("buildMetrics: Item %s highlightedquery unparseable: %s\n", item.GetId(), item.GetHighlightedQuery())
+			}
+		}
+		switch item.(type) {
+			case *Edge:
+				if len(item.GetThicknessQuery()) > 0 {
+					log.Debugf("buildMetrics: Item %s have thicknessquery: %s\n", item.GetId(), item.GetThicknessQuery())
+					r := gDSVarCompRegex.FindStringSubmatch(item.GetThicknessQuery())
+					if len(r) > 1 {
+						var value float64
+						dsname := strings.TrimSpace(r[1])
+						log.Debugf("buildMetrics: datasource from thicknessquery : %s\n", dsname)
+						for _, d := range gDataSources {
+							if strings.EqualFold(d.Name, dsname) {
+								value, err = d.GetData(timeRange)
+								if err != nil {
+									return nil, err
+								}
+								break
+							}
+						}
+						log.Debugf("buildMetrics: Replace %s thickness with %s\n", item.GetId(), fmt.Sprintf("%0.0f", value))
+						item.SetThickness(value)
+					} else {
+						log.Errorf("buildMetrics: Item %s thicknessquery unparseable: %s\n", item.GetId(), item.GetThicknessQuery())
+					}
+				}
+		}
 	}
 	return items, nil
 }
@@ -263,7 +329,7 @@ func getGraph(name string) (Graph, error) {
 	return Graph{}, fmt.Errorf("Graph not found: %s", name)
 }
 
-func initRoutes(r *gin.Engine) {
+func initRoutes(r *gin.Engine, confFile string) {
 	r.GET("/ping", func(c *gin.Context) {
 		c.JSON(http.StatusOK, gin.H{
 			"message": "pong",
@@ -272,7 +338,10 @@ func initRoutes(r *gin.Engine) {
 	
 	// An endpoint to force read of configuration file
 	r.POST("/reload", func(c *gin.Context) {
-		reloadConfigFile()
+		if err := reloadConfigFile(confFile); err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+			return
+		}
 		c.JSON(http.StatusOK, gin.H{
 			"message": "configuration successfully reloaded",
 		})
@@ -361,21 +430,99 @@ func toggleDebug() {
 	}
 }
 
-func reloadConfigFile() {
-	// First reread config file
-	if err := viper.ReadInConfig(); err != nil {
-		if _, ok := err.(viper.ConfigFileNotFoundError); ok {
-			log.Fatalf("config file not found")
-			os.Exit(1)
-		} else {
-			log.Fatalf("unknown error looking for config file: %v", err)
-			os.Exit(1)
-		}
+// Deep copy src Node into a new memory space
+func newNodeClone(src *Node) *Node {
+	return &Node{
+		Name: src.Name,
+		Id: src.Id,
+		Title: src.Title,
+		Subtitle: src.Subtitle,
+		MainStat: src.MainStat,
+		MainStatQuery: src.MainStatQuery,
+		MainStatFormat: src.MainStatFormat,
+		SecondaryStat: src.SecondaryStat,
+		SecondaryStatQuery: src.SecondaryStatQuery,
+		SecondaryStatFormat: src.SecondaryStatFormat,
+		Color: src.Color,
+		Icon: src.Icon,
+		NodeRadius: src.NodeRadius,
+		Highlighted: src.Highlighted,
+		HighlightedQuery: src.HighlightedQuery,
 	}
+}
+
+// Deep copy src Edge into a new memory space
+func newEdgeClone(src *Edge) *Edge {
+	return &Edge{
+		Id: src.Id,
+		Source: src.Source,
+		Target: src.Target,
+		MainStat: src.MainStat,
+		MainStatQuery: src.MainStatQuery,
+		MainStatFormat: src.MainStatFormat,
+		SecondaryStat: src.SecondaryStat,
+		SecondaryStatQuery: src.SecondaryStatQuery,
+		SecondaryStatFormat: src.SecondaryStatFormat,
+		Color: src.Color,
+		Thickness: src.Thickness,
+		ThicknessQuery: src.ThicknessQuery,
+		Highlighted: src.Highlighted,
+		HighlightedQuery: src.HighlightedQuery,
+		StrokeDashArray: src.StrokeDashArray,
+	}
+}
+
+// This function assume we already have a running configuration.
+func reloadConfigFile(confFile string) error {
+	oldConfigRestored := false
+	// We need to keep this config, incase the new one is b0rken
+	fname := fmt.Sprintf("/tmp/nodegopher.%d.yaml", os.Getpid())
+	if err := viper.WriteConfigAs(fname); err != nil {
+		log.Errorf("Unable to save current running config to %s, wont reload configuration.\n", fname)
+		return fmt.Errorf("Unable to save current configuration, configuration not reloaded. See logs.")
+	}
+	defer os.Remove(fname)
+
+	// Reread config file
+	if oldErr := viper.ReadInConfig(); oldErr != nil {
+		if _, ok := oldErr.(viper.ConfigFileNotFoundError); ok {
+			log.Errorf("config file not found")
+		} else {
+			log.Errorf("unknown error looking for config file: %v", oldErr)
+		}
+		// Restore old configuration and notify.
+		log.Debugf("Fallback on previous configuration.\n")
+		viper.SetConfigFile(fname)
+		if err := viper.ReadInConfig(); err != nil {
+			log.Fatalf("Unable to restore configuration, and new is invalid. fix it now.\n")
+		}
+		viper.SetConfigFile(confFile)
+		oldConfigRestored = true
+	}
+
+	switch viper.Get("language").(string) {
+		case "english":
+			gPrinter = message.NewPrinter(language.English)
+		case "french":
+			gPrinter = message.NewPrinter(language.French)
+		case "german":
+			gPrinter = message.NewPrinter(language.German)
+		case "ukrainian":
+			gPrinter = message.NewPrinter(language.Ukrainian)
+		case "arabic":
+			gPrinter = message.NewPrinter(language.Arabic)
+		case "chinese":
+			gPrinter = message.NewPrinter(language.Chinese)
+		default:
+			log.Errorf("Language not implemented: %s. Fallback to english\n", viper.Get("language").(string))
+			gPrinter = message.NewPrinter(language.English)
+	}
+
 	// then clear current config, after acquiring WriteLock
 	gCfgMutex.Lock()
 	defer gCfgMutex.Unlock()
 
+	// We need to keep this config, incase the new one is b0rken
 	for _, g := range gGraphs {
 		g.Nodes = nil
 		g.Edges = nil
@@ -395,34 +542,40 @@ func reloadConfigFile() {
 			Edges []Edge `yaml:"edges"`
 		}{}
 		yaml.Unmarshal(yd, &tmp)
-		var graphNodes []Item
-		var graphEdges []Item
-		for _, n := range tmp.Nodes {
-			graphNodes = append(graphNodes, &n)
-		}
-		for _, e := range tmp.Edges {
-			graphEdges = append(graphEdges, &e)
-		}
-		
+
 		graph := Graph{
 			Name:  tmp.Name,
-			Nodes: graphNodes,
-			Edges: graphEdges,
+		}
+		for _, n := range tmp.Nodes {
+			// Deep copy Node so garbage collecting tmp won't pull the carpet under our feet
+			graph.Nodes = append(graph.Nodes, newNodeClone(&n))
+		}
+		for _, e := range tmp.Edges {
+			// Deep copy Edge
+			graph.Edges = append(graph.Edges, newEdgeClone(&e))
 		}
 		gGraphs = append(gGraphs, graph)
 	}
 
 	if viper.Get("datasources") == nil {
-		log.Printf("no datasources found, data will be static")
-		return
+		log.Warningf("no datasources found, data will be static")
+		return nil
 	}
 	dss := viper.Get("datasources").([]interface{})
 	for _, d := range dss {
 		yd, _ := yaml.Marshal(d)
 		var ds PromDataSourceConfig
 		yaml.Unmarshal(yd, &ds)
+		// Set default Values
+		if ds.Timeout == 0 {
+			ds.Timeout = gDefaultDSTimeout
+		}
 		gDataSources = append(gDataSources, ds)
 	}
+	if oldConfigRestored {
+		return fmt.Errorf("Unable to load new configuration, keeping old one. See logs.")
+	}
+	return nil
 }
 
 func main() {
@@ -475,7 +628,7 @@ func main() {
 	// FIXME: Watch config changes. Does not work on FreeBSD. TODO: Test with linux
 	viper.OnConfigChange(func(e fsnotify.Event) {
 		log.Printf("Config file changed, reloading data\n")
-		reloadConfigFile()
+		reloadConfigFile(confFile)
 	})
 
 	// Lets reload config on SIGHUP
@@ -485,11 +638,11 @@ func main() {
 		for {
 			_ = <- sigs
 			log.Infof("SIGHUP received, reloading configuration\n")
-			reloadConfigFile()
+			reloadConfigFile(confFile)
 		}
 	}()
 
-	reloadConfigFile()
+	reloadConfigFile(confFile)
 
 	// Capture variable name. There should be only one variable. Space is tolerated before and after name.
 	gDSVarCompRegex = regexp.MustCompile(`^\{\{(?:\ )?([a-zA-Z0-9\-_]+)(?:\ )?\}\}$`)
@@ -500,6 +653,6 @@ func main() {
 	log.Printf("Starting NodeGopher v.%s\n", gVersion)
 
 	r := gin.Default()
-	initRoutes(r)
+	initRoutes(r, confFile)
 	r.Run(listen)
 }

nodes.go

@@ -22,7 +22,8 @@ type Node struct {
 	Color               string  `yaml:"color,omitempty" json:"color,omitempty"`
 	Icon                string  `yaml:"icon,omitempty" json:"icon,omitempty"`
 	NodeRadius          int     `yaml:"noderadius,omitempty" json:"noderadius,omitempty"`
-	HighLighted         bool    `yaml:"highlighted,omitempty" json:"hightlighted,omitempty"`
+	Highlighted         bool    `yaml:"highlighted,omitempty" json:"hightlighted,omitempty"`
+	HighlightedQuery    string  `yaml:"highlightedquery,omitempty" json:"highlightedquery,omitempty"`
 } 
 
 func (n Node) GetId() string {
@@ -61,6 +62,25 @@ func (n *Node) SetSecondaryStat(stat string) {
 	n.SecondaryStat = fmt.Sprintf("%s", stat)
 }
 
+// Have to be implemented to satisfy Item interface
+func (n *Node) GetThicknessQuery() string {
+	panic("Not an Edge")
+	return ""
+}
+
+// Have to be implemented to satisfy Item interface
+func (n *Node) SetThickness(thickness float64) {
+	panic("Not an Edge")
+}
+
+func (n *Node) GetHighlightedQuery() string {
+	return n.HighlightedQuery
+}
+
+func (n *Node) SetHighlighted(highlighted bool) {
+	n.Highlighted = highlighted
+}
+
 // Custom marshaler to not send (main|secondary)statquery
 func (n Node) MarshalJSON() ([]byte, error) {
 	jsonRes := `{"name":"` + n.Name + `","id":"` + n.Id + `"`
@@ -85,7 +105,7 @@ func (n Node) MarshalJSON() ([]byte, error) {
 	if n.NodeRadius > 0 {
 		jsonRes += `,"noderadius":` + strconv.Itoa(n.NodeRadius)
 	}
-	if n.HighLighted {
+	if n.Highlighted {
 		jsonRes += `,"highlighted":true`
 	}
 	// TODO : n.StrokeDashArray