From 086a163f3cf451d37d90c02a8a20706379932ad9 Mon Sep 17 00:00:00 2001
From: genofire <geno+dev@fireorbit.de>
Date: Sun, 14 Jun 2020 13:25:30 +0200
Subject: [PATCH] prometheus: yanic_node_up=0

---
 webserver/prometheus/exporter.go  | 47 +++++++++++++-----------
 webserver/prometheus/transform.go | 61 ++++++++++++++++++-------------
 2 files changed, 62 insertions(+), 46 deletions(-)

diff --git a/webserver/prometheus/exporter.go b/webserver/prometheus/exporter.go
index 391529fc..9268ae40 100644
--- a/webserver/prometheus/exporter.go
+++ b/webserver/prometheus/exporter.go
@@ -33,7 +33,7 @@ func (ex *Exporter) ServeHTTP(res http.ResponseWriter, req *http.Request) {
 			return
 		}
 		ip = node.Address.IP
-		if ex.writeNode(res, node) {
+		if ex.writeNode(res, node, true) {
 			log.WithFields(map[string]interface{}{
 				"ip":      ip,
 				"node_id": nodeID,
@@ -51,22 +51,17 @@ func (ex *Exporter) ServeHTTP(res http.ResponseWriter, req *http.Request) {
 			nodeID = n.Nodeinfo.NodeID
 			return n_addr != nil && ip.Equal(n_addr.IP)
 		})
-		getOne := false
 		if len(node_select) == 1 {
-			if ex.writeNode(res, node_select[0]) {
-				getOne = true
+			if ex.writeNode(res, node_select[0], true) {
+				log.WithFields(map[string]interface{}{
+					"ip":      ip,
+					"node_id": nodeID,
+				}).Debug("take node from cache")
+				return
 			}
 		} else if len(node_select) > 1 {
 			log.Error("strange count of nodes")
 		}
-
-		if getOne {
-			log.WithFields(map[string]interface{}{
-				"ip":      ip,
-				"node_id": nodeID,
-			}).Debug("take node from cache")
-			return
-		}
 	} else {
 		http.Error(res, "please request with ?ip= or ?node_id=", http.StatusNotFound)
 		return
@@ -88,26 +83,36 @@ func (ex *Exporter) ServeHTTP(res http.ResponseWriter, req *http.Request) {
 		http.Error(res, "not able to fetch this node", http.StatusGatewayTimeout)
 		return
 	}
-	if ex.writeNode(res, node) {
-		return
-	}
-	http.Error(res, "not able to fetch new values from this node", http.StatusGatewayTimeout)
+	ex.writeNode(res, node, false)
 }
 
-func (ex *Exporter) writeNode(res http.ResponseWriter, node *runtime.Node) bool {
+func (ex *Exporter) writeNode(res http.ResponseWriter, node *runtime.Node, dry bool) bool {
+	logger := log.WithField("database", "prometheus")
+	if nodeinfo := node.Nodeinfo; nodeinfo != nil {
+		logger = logger.WithField("node_id", nodeinfo.NodeID)
+	}
+
 	if !time.Now().Before(node.Lastseen.GetTime().Add(ex.config.Outdated.Duration)) {
+		if dry {
+			return false
+		}
+		m := Metric{Labels: MetricLabelsFromNode(node), Name: "yanic_node_up", Value: 0}
+		str, err := m.String()
+		if err == nil {
+			io.WriteString(res, str+"\n")
+		} else {
+			logger.Warnf("not able to get metrics from node: %s", err)
+			http.Error(res, "not able to generate metric from node", http.StatusInternalServerError)
+		}
 		return false
 	}
+
 	metrics := MetricsFromNode(ex.nodes, node)
 	for _, m := range metrics {
 		str, err := m.String()
 		if err == nil {
 			io.WriteString(res, str+"\n")
 		} else {
-			logger := log.WithField("database", "prometheus")
-			if nodeinfo := node.Nodeinfo; nodeinfo != nil {
-				logger = logger.WithField("node_id", nodeinfo.NodeID)
-			}
 			logger.Warnf("not able to get metrics from node: %s", err)
 			http.Error(res, "not able to generate metric from node", http.StatusInternalServerError)
 		}
diff --git a/webserver/prometheus/transform.go b/webserver/prometheus/transform.go
index 1fe70c4d..570feb96 100644
--- a/webserver/prometheus/transform.go
+++ b/webserver/prometheus/transform.go
@@ -4,35 +4,16 @@ import (
 	"github.com/FreifunkBremen/yanic/runtime"
 )
 
-func MetricsFromNode(nodes *runtime.Nodes, node *runtime.Node) []Metric {
-	m := []Metric{}
-
-	// before node metrics to get link statics undependent of node validation
-	for _, link := range nodes.NodeLinks(node) {
-		m = append(m, Metric{
-			Labels: map[string]interface{}{
-				"source_id":   link.SourceID,
-				"source_addr": link.SourceAddress,
-				"target_id":   link.TargetID,
-				"target_addr": link.TargetAddress,
-			},
-			Name:  "yanic_link",
-			Value: link.TQ * 100,
-		})
-	}
+func MetricLabelsFromNode(node *runtime.Node) (labels map[string]interface{}) {
+	labels = make(map[string]interface{})
 
 	nodeinfo := node.Nodeinfo
-	stats := node.Statistics
-
-	// validation
-	if nodeinfo == nil || stats == nil {
-		return m
+	if nodeinfo == nil {
+		return
 	}
 
-	labels := map[string]interface{}{
-		"node_id":  nodeinfo.NodeID,
-		"hostname": nodeinfo.Hostname,
-	}
+	labels["node_id"] =  nodeinfo.NodeID
+	labels["hostname"] = nodeinfo.Hostname
 
 	if nodeinfo.System.SiteCode != "" {
 		labels["site_code"] = nodeinfo.System.SiteCode
@@ -59,6 +40,36 @@ func MetricsFromNode(nodes *runtime.Nodes, node *runtime.Node) []Metric {
 		labels["location_long"] = location.Longitude
 	}
 
+	return
+}
+
+func MetricsFromNode(nodes *runtime.Nodes, node *runtime.Node) []Metric {
+	m := []Metric{}
+
+	// before node metrics to get link statics undependent of node validation
+	for _, link := range nodes.NodeLinks(node) {
+		m = append(m, Metric{
+			Labels: map[string]interface{}{
+				"source_id":   link.SourceID,
+				"source_addr": link.SourceAddress,
+				"target_id":   link.TargetID,
+				"target_addr": link.TargetAddress,
+			},
+			Name:  "yanic_link",
+			Value: link.TQ * 100,
+		})
+	}
+
+	nodeinfo := node.Nodeinfo
+	stats := node.Statistics
+
+	// validation
+	if nodeinfo == nil || stats == nil {
+		return m
+	}
+
+	labels := MetricLabelsFromNode(node)
+
 	addMetric := func(name string, value interface{}) {
 		m = append(m, Metric{Labels: labels, Name: "yanic_" + name, Value: value})
 	}