feat: created dashboard for golang runtime metrics

golang/README.md

@@ -0,0 +1,73 @@
+# Golang Runtime Metrics Dashboard - Prometheus
+
+
+### OS Threads Histogram Panel
+1. Tracks the number of goroutines currently in use by the application.
+2. Tracks CGO calls, which indicate OS-level threads involvement if CGO is used.
+
+The code snippet below calculates the `go_goroutines_count` and `go_cgo_calls_count`
+
+![OS Threads Histogram](assets/os-threads-histogram.png)
+
+```
+package main
+
+import (
+    "log"
+    "net/http"
+    "runtime"
+    "time"
+
+    "github.com/prometheus/client_golang/prometheus"
+    "github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+var (
+    // Gauge for OS-level goroutines count
+    goRoutineCount = prometheus.NewGauge(prometheus.GaugeOpts{
+        Name: "go_goroutines_count",
+        Help: "Number of goroutines currently managed by the Go runtime.",
+    })
+
+    // Counter for CGO calls (proxy for OS thread use when working with CGO)
+    cgoCallCount = prometheus.NewCounterFunc(
+        prometheus.CounterOpts{
+            Name: "go_cgo_calls_count",
+            Help: "Number of CGO calls made by the Go runtime.",
+        },
+        func() float64 {
+            return float64(runtime.NumCgoCall())
+        },
+    )
+)
+
+func initMetrics() {
+    // Register the goroutine count gauge
+    prometheus.MustRegister(goRoutineCount)
+    prometheus.MustRegister(cgoCallCount)
+}
+
+func main() {
+    initMetrics()
+
+    // Goroutine to periodically update goroutine count
+    go func() {
+        for {
+            goRoutineCount.Set(float64(runtime.NumGoroutine()))
+            time.Sleep(5 * time.Second)
+        }
+    }()
+
+    // Expose metrics on port 2112
+    http.Handle("/metrics", promhttp.Handler())
+    log.Println("Starting server on :2112")
+    if err := http.ListenAndServe(":2112", nil); err != nil {
+        log.Fatalf("Failed to start server: %v", err)
+    }
+}
+
+```
+
+### Sections
+
+- os-threads-histogram

golang/golang-prometheus.json

@@ -0,0 +1,179 @@
+{
+    "annotations": {
+      "list": [
+        {
+          "builtIn": 1,
+          "datasource": {
+            "type": "grafana",
+            "uid": "-- Grafana --"
+          },
+          "enable": true,
+          "hide": true,
+          "iconColor": "rgba(0, 211, 255, 1)",
+          "name": "Annotations & Alerts",
+          "type": "dashboard"
+        }
+      ]
+    },
+    "description": "Prometheus Go runtime exporter ",
+    "editable": true,
+    "fiscalYearStartMonth": 0,
+    "graphTooltip": 0,
+    "id": 45,
+    "links": [],
+    "panels": [
+      {
+        "datasource": {
+          "type": "prometheus"
+        },
+        "fieldConfig": {
+          "defaults": {
+            "color": {
+              "mode": "palette-classic"
+            },
+            "custom": {
+              "axisBorderShow": false,
+              "axisCenteredZero": false,
+              "axisColorMode": "text",
+              "axisLabel": "",
+              "axisPlacement": "auto",
+              "barAlignment": 0,
+              "barWidthFactor": 0.6,
+              "drawStyle": "bars",
+              "fillOpacity": 100,
+              "gradientMode": "none",
+              "hideFrom": {
+                "legend": false,
+                "tooltip": false,
+                "viz": false
+              },
+              "insertNulls": false,
+              "lineInterpolation": "linear",
+              "lineWidth": 1,
+              "pointSize": 5,
+              "scaleDistribution": {
+                "type": "linear"
+              },
+              "showPoints": "never",
+              "spanNulls": false,
+              "stacking": {
+                "group": "A",
+                "mode": "normal"
+              },
+              "thresholdsStyle": {
+                "mode": "off"
+              }
+            },
+            "mappings": [],
+            "thresholds": {
+              "mode": "absolute",
+              "steps": [
+                {
+                  "color": "green",
+                  "value": null
+                },
+                {
+                  "color": "red",
+                  "value": 80
+                }
+              ]
+            }
+          },
+          "overrides": []
+        },
+        "gridPos": {
+          "h": 9,
+          "w": 12,
+          "x": 0,
+          "y": 0
+        },
+        "id": 1,
+        "options": {
+          "legend": {
+            "calcs": [],
+            "displayMode": "list",
+            "placement": "bottom",
+            "showLegend": true
+          },
+          "tooltip": {
+            "mode": "single",
+            "sort": "none"
+          }
+        },
+        "pluginVersion": "11.3.0",
+        "targets": [
+          {
+            "datasource": {
+              "uid": "$datasource"
+            },
+            "expr": "sum(rate(go_threads{job=\"$job\", instance=\"$instance\"}[5m])) by (instance)",
+            "format": "time_series",
+            "interval": "",
+            "intervalFactor": 2,
+            "legendFormat": "{{instance}}",
+            "refId": "A"
+          }
+        ],
+        "title": "OS Threads Histogram",
+        "type": "timeseries"
+      }
+    ],
+    "preload": false,
+    "refresh": "",
+    "schemaVersion": 40,
+    "tags": [
+      "go",
+      "golang"
+    ],
+    "templating": {
+      "list": [
+        {
+          "allValue": ".*",
+          "current": {
+            "text": "All",
+            "value": "$__all"
+          },
+          "includeAll": true,
+          "name": "datasource",
+          "options": [],
+          "query": "prometheus",
+          "refresh": 1,
+          "type": "datasource"
+        },
+        {
+          "current": {
+            "text": "go",
+            "value": "go"
+          },
+          "datasource": {
+            "type": "prometheus"
+          },
+          "name": "job",
+          "options": [],
+          "query": "label_values(go_threads, job)",
+          "refresh": 1,
+          "type": "query"
+        },
+        {
+          "datasource": {
+            "type": "prometheus"
+          },
+          "name": "instance",
+          "options": [],
+          "query": "label_values(go_threads, instance)",
+          "refresh": 1,
+          "type": "query"
+        }
+      ]
+    },
+    "time": {
+      "from": "now-2d",
+      "to": "now"
+    },
+    "timepicker": {},
+    "timezone": "",
+    "title": "Golang Runtime Metrics Dashboard",
+    "uid": "ce293qxwouuwwd",
+    "version": 5,
+    "weekStart": ""
+  }