From ec4d6379d0581a057b21d6d8d61bf08a907199a1 Mon Sep 17 00:00:00 2001
From: Felix Buehler <account@buehler.rocks>
Date: Sun, 4 Jun 2023 15:23:47 +0200
Subject: [PATCH] service/hedgedoc: add monitoring and dashboard

---
 modules/services/hedgedoc/default.nix |  24 +
 pkgs/grafana-dashboards/default.nix   |  10 +
 pkgs/grafana-dashboards/hedgedoc.json | 800 ++++++++++++++++++++++++++
 3 files changed, 834 insertions(+)
 create mode 100644 pkgs/grafana-dashboards/hedgedoc.json

diff --git a/modules/services/hedgedoc/default.nix b/modules/services/hedgedoc/default.nix
index 0be9e38..f7507bc 100644
--- a/modules/services/hedgedoc/default.nix
+++ b/modules/services/hedgedoc/default.nix
@@ -50,6 +50,30 @@ in
     #systemd.services.hedgedoc.serviceConfig.StateDirectory = lib.mkForce "/var/lib/hedgedoc";
     systemd.services.hedgedoc.serviceConfig.StateDirectory = lib.mkForce "hedgedoc";
 
+    services.prometheus = {
+      scrapeConfigs = [
+        {
+          job_name = "hedgedoc";
+          static_configs = [
+            {
+              targets = [ "127.0.0.1:${toString cfg.port}" ];
+              labels = {
+                instance = config.networking.hostName;
+              };
+            }
+          ];
+        }
+      ];
+    };
+
+    services.grafana.provision.dashboards.settings.providers = [
+      {
+        name = "Hedgedoc";
+        options.path = pkgs.grafana-dashboards.hedgedoc;
+        disableDeletion = true;
+      }
+    ];
+
     my.services.nginx.virtualHosts = [
       {
         subdomain = "notes";
diff --git a/pkgs/grafana-dashboards/default.nix b/pkgs/grafana-dashboards/default.nix
index 54f592b..bdf8dee 100644
--- a/pkgs/grafana-dashboards/default.nix
+++ b/pkgs/grafana-dashboards/default.nix
@@ -67,6 +67,16 @@ in
     src = ./navidrome.json; # sadly data source is not detected
   });
 
+  # taken from https://gitlab.archlinux.org/archlinux/infrastructure/-/blob/master/roles/grafana/files/dashboards/Hedgedoc.json?ref_type=heads
+  hedgedoc = (buildGrafanaDashboard {
+    id = -1;
+    pname = "hedgedoc";
+    version = "1";
+    hash = lib.fakeSha256;
+  }).overrideAttrs (self: super: {
+    src = ./hedgedoc.json; # sadly data source is not detected
+  });
+
   cadvisor = buildGrafanaDashboard {
     id = 10619;
     pname = "cadvisor";
diff --git a/pkgs/grafana-dashboards/hedgedoc.json b/pkgs/grafana-dashboards/hedgedoc.json
new file mode 100644
index 0000000..cbf014e
--- /dev/null
+++ b/pkgs/grafana-dashboards/hedgedoc.json
@@ -0,0 +1,800 @@
+{
+  "annotations": {
+    "list": [
+      {
+        "builtIn": 1,
+        "datasource": {
+          "type": "datasource",
+          "uid": "grafana"
+        },
+        "enable": true,
+        "hide": true,
+        "iconColor": "rgba(0, 211, 255, 1)",
+        "name": "Annotations & Alerts",
+        "type": "dashboard"
+      }
+    ]
+  },
+  "editable": true,
+  "fiscalYearStartMonth": 0,
+  "graphTooltip": 0,
+  "id": 55,
+  "links": [],
+  "liveNow": false,
+  "panels": [
+    {
+      "datasource": {
+        "type": "prometheus",
+        "uid": "KNkR71YVk"
+      },
+      "description": "Hedgedoc notes stats",
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "thresholds"
+          },
+          "mappings": [],
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 1000
+              }
+            ]
+          }
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 6,
+        "w": 24,
+        "x": 0,
+        "y": 0
+      },
+      "id": 2,
+      "options": {
+        "colorMode": "value",
+        "graphMode": "area",
+        "justifyMode": "auto",
+        "orientation": "auto",
+        "reduceOptions": {
+          "calcs": [
+            "lastNotNull"
+          ],
+          "fields": "",
+          "values": false
+        },
+        "text": {},
+        "textMode": "auto"
+      },
+      "pluginVersion": "9.5.2",
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "KNkR71YVk"
+          },
+          "exemplar": true,
+          "expr": "hedgedoc_notes",
+          "interval": "",
+          "legendFormat": "Notes",
+          "queryType": "randomWalk",
+          "refId": "A"
+        },
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "KNkR71YVk"
+          },
+          "exemplar": true,
+          "expr": "hedgedoc_online_notes  ",
+          "hide": false,
+          "interval": "",
+          "legendFormat": "Online notes ",
+          "refId": "B"
+        },
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "KNkR71YVk"
+          },
+          "exemplar": true,
+          "expr": "hedgedoc_registered_users",
+          "hide": false,
+          "interval": "",
+          "legendFormat": "Registered users",
+          "refId": "C"
+        },
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "KNkR71YVk"
+          },
+          "exemplar": true,
+          "expr": "hedgedoc_online_users",
+          "hide": false,
+          "instant": false,
+          "interval": "",
+          "legendFormat": "Online users",
+          "refId": "D"
+        }
+      ],
+      "title": "hedgedoc stats",
+      "type": "stat"
+    },
+    {
+      "cards": {},
+      "color": {
+        "cardColor": "#b4ff00",
+        "colorScale": "sqrt",
+        "colorScheme": "interpolateOranges",
+        "exponent": 0.5,
+        "mode": "spectrum"
+      },
+      "dataFormat": "timeseries",
+      "datasource": {
+        "type": "prometheus",
+        "uid": "KNkR71YVk"
+      },
+      "description": "",
+      "fieldConfig": {
+        "defaults": {
+          "custom": {
+            "hideFrom": {
+              "legend": false,
+              "tooltip": false,
+              "viz": false
+            },
+            "scaleDistribution": {
+              "type": "linear"
+            }
+          }
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 8,
+        "w": 24,
+        "x": 0,
+        "y": 6
+      },
+      "heatmap": {},
+      "hideZeroBuckets": false,
+      "highlightCards": true,
+      "id": 6,
+      "legend": {
+        "show": false
+      },
+      "options": {
+        "calculate": true,
+        "calculation": {},
+        "cellGap": 2,
+        "cellValues": {},
+        "color": {
+          "exponent": 0.5,
+          "fill": "#b4ff00",
+          "mode": "scheme",
+          "reverse": false,
+          "scale": "exponential",
+          "scheme": "Oranges",
+          "steps": 128
+        },
+        "exemplars": {
+          "color": "rgba(255,0,255,0.7)"
+        },
+        "filterValues": {
+          "le": 1e-9
+        },
+        "legend": {
+          "show": false
+        },
+        "rowsFrame": {
+          "layout": "auto"
+        },
+        "showValue": "never",
+        "tooltip": {
+          "show": true,
+          "yHistogram": false
+        },
+        "yAxis": {
+          "axisPlacement": "left",
+          "reverse": false,
+          "unit": "s"
+        }
+      },
+      "pluginVersion": "9.5.2",
+      "reverseYBuckets": false,
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "KNkR71YVk"
+          },
+          "exemplar": true,
+          "expr": "sum by (le) (rate(http_request_duration_seconds_bucket{job=\"hedgedoc\"}[3m]))",
+          "interval": "",
+          "legendFormat": "{{ le }}",
+          "queryType": "randomWalk",
+          "refId": "A"
+        }
+      ],
+      "title": "Request duration",
+      "tooltip": {
+        "show": true,
+        "showHistogram": false
+      },
+      "type": "heatmap",
+      "xAxis": {
+        "show": true
+      },
+      "yAxis": {
+        "format": "s",
+        "logBase": 1,
+        "show": true
+      },
+      "yBucketBound": "auto"
+    },
+    {
+      "aliasColors": {},
+      "bars": false,
+      "dashLength": 10,
+      "dashes": false,
+      "datasource": {
+        "type": "prometheus",
+        "uid": "KNkR71YVk"
+      },
+      "fill": 1,
+      "fillGradient": 0,
+      "gridPos": {
+        "h": 7,
+        "w": 10,
+        "x": 0,
+        "y": 14
+      },
+      "hiddenSeries": false,
+      "id": 8,
+      "legend": {
+        "alignAsTable": true,
+        "avg": true,
+        "current": true,
+        "max": true,
+        "min": true,
+        "show": true,
+        "total": false,
+        "values": true
+      },
+      "lines": true,
+      "linewidth": 1,
+      "links": [],
+      "nullPointMode": "null",
+      "options": {
+        "alertThreshold": true
+      },
+      "paceLength": 10,
+      "percentage": false,
+      "pluginVersion": "9.5.2",
+      "pointradius": 2,
+      "points": false,
+      "renderer": "flot",
+      "seriesOverrides": [],
+      "spaceLength": 10,
+      "stack": false,
+      "steppedLine": false,
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "KNkR71YVk"
+          },
+          "exemplar": true,
+          "expr": "irate(process_cpu_user_seconds_total{job=\"hedgedoc\"}[2m]) * 100",
+          "format": "time_series",
+          "interval": "",
+          "intervalFactor": 1,
+          "legendFormat": "User CPU",
+          "refId": "A"
+        },
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "KNkR71YVk"
+          },
+          "exemplar": true,
+          "expr": "irate(process_cpu_system_seconds_total{job=\"hedgedoc\"}[2m]) * 100",
+          "format": "time_series",
+          "interval": "",
+          "intervalFactor": 1,
+          "legendFormat": "Sys CPU",
+          "refId": "B"
+        }
+      ],
+      "thresholds": [],
+      "timeRegions": [],
+      "title": "Process CPU Usage",
+      "tooltip": {
+        "shared": true,
+        "sort": 0,
+        "value_type": "individual"
+      },
+      "type": "graph",
+      "xaxis": {
+        "mode": "time",
+        "show": true,
+        "values": []
+      },
+      "yaxes": [
+        {
+          "$$hashKey": "object:147",
+          "format": "percent",
+          "logBase": 1,
+          "show": true
+        },
+        {
+          "$$hashKey": "object:148",
+          "format": "short",
+          "logBase": 1,
+          "show": true
+        }
+      ],
+      "yaxis": {
+        "align": false
+      }
+    },
+    {
+      "aliasColors": {},
+      "bars": false,
+      "dashLength": 10,
+      "dashes": false,
+      "datasource": {
+        "type": "prometheus",
+        "uid": "KNkR71YVk"
+      },
+      "fill": 1,
+      "fillGradient": 0,
+      "gridPos": {
+        "h": 7,
+        "w": 9,
+        "x": 10,
+        "y": 14
+      },
+      "hiddenSeries": false,
+      "id": 10,
+      "legend": {
+        "alignAsTable": true,
+        "avg": true,
+        "current": true,
+        "max": true,
+        "min": true,
+        "show": true,
+        "total": false,
+        "values": true
+      },
+      "lines": true,
+      "linewidth": 1,
+      "links": [],
+      "nullPointMode": "null",
+      "options": {
+        "alertThreshold": true
+      },
+      "paceLength": 10,
+      "percentage": false,
+      "pluginVersion": "9.5.2",
+      "pointradius": 2,
+      "points": false,
+      "renderer": "flot",
+      "seriesOverrides": [],
+      "spaceLength": 10,
+      "stack": false,
+      "steppedLine": false,
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "KNkR71YVk"
+          },
+          "exemplar": true,
+          "expr": "nodejs_eventloop_lag_seconds{job=\"hedgedoc\"}",
+          "format": "time_series",
+          "interval": "",
+          "intervalFactor": 1,
+          "legendFormat": "hedgedoc",
+          "refId": "A"
+        }
+      ],
+      "thresholds": [],
+      "timeRegions": [],
+      "title": "Event Loop Lag",
+      "tooltip": {
+        "shared": true,
+        "sort": 0,
+        "value_type": "individual"
+      },
+      "type": "graph",
+      "xaxis": {
+        "mode": "time",
+        "show": true,
+        "values": []
+      },
+      "yaxes": [
+        {
+          "$$hashKey": "object:205",
+          "format": "s",
+          "logBase": 1,
+          "show": true
+        },
+        {
+          "$$hashKey": "object:206",
+          "format": "short",
+          "logBase": 1,
+          "show": true
+        }
+      ],
+      "yaxis": {
+        "align": false
+      }
+    },
+    {
+      "aliasColors": {},
+      "bars": false,
+      "dashLength": 10,
+      "dashes": false,
+      "datasource": {
+        "type": "prometheus",
+        "uid": "KNkR71YVk"
+      },
+      "description": "Length of connection socket queue and connection busy indicates that realtime currently connecting",
+      "fill": 1,
+      "fillGradient": 0,
+      "gridPos": {
+        "h": 7,
+        "w": 5,
+        "x": 19,
+        "y": 14
+      },
+      "hiddenSeries": false,
+      "id": 4,
+      "legend": {
+        "avg": false,
+        "current": false,
+        "max": false,
+        "min": false,
+        "show": true,
+        "total": false,
+        "values": false
+      },
+      "lines": true,
+      "linewidth": 1,
+      "nullPointMode": "null",
+      "options": {
+        "alertThreshold": true
+      },
+      "percentage": false,
+      "pluginVersion": "9.5.2",
+      "pointradius": 2,
+      "points": false,
+      "renderer": "flot",
+      "seriesOverrides": [],
+      "spaceLength": 10,
+      "stack": false,
+      "steppedLine": false,
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "KNkR71YVk"
+          },
+          "exemplar": true,
+          "expr": "hedgedoc_connection_busy",
+          "interval": "",
+          "legendFormat": "connections busy",
+          "queryType": "randomWalk",
+          "refId": "A"
+        },
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "KNkR71YVk"
+          },
+          "exemplar": true,
+          "expr": "hedgedoc_connection_socket_queue_length",
+          "hide": false,
+          "interval": "",
+          "legendFormat": "socket queue length",
+          "refId": "B"
+        }
+      ],
+      "thresholds": [],
+      "timeRegions": [],
+      "title": "Connections",
+      "tooltip": {
+        "shared": true,
+        "sort": 0,
+        "value_type": "individual"
+      },
+      "type": "graph",
+      "xaxis": {
+        "mode": "time",
+        "show": true,
+        "values": []
+      },
+      "yaxes": [
+        {
+          "$$hashKey": "object:225",
+          "format": "short",
+          "logBase": 1,
+          "show": true
+        },
+        {
+          "$$hashKey": "object:226",
+          "format": "short",
+          "logBase": 1,
+          "show": true
+        }
+      ],
+      "yaxis": {
+        "align": false
+      }
+    },
+    {
+      "aliasColors": {},
+      "bars": false,
+      "dashLength": 10,
+      "dashes": false,
+      "datasource": {
+        "type": "prometheus",
+        "uid": "KNkR71YVk"
+      },
+      "fill": 1,
+      "fillGradient": 0,
+      "gridPos": {
+        "h": 7,
+        "w": 16,
+        "x": 0,
+        "y": 21
+      },
+      "hiddenSeries": false,
+      "id": 12,
+      "legend": {
+        "alignAsTable": true,
+        "avg": true,
+        "current": true,
+        "max": true,
+        "min": true,
+        "rightSide": true,
+        "show": true,
+        "total": false,
+        "values": true
+      },
+      "lines": true,
+      "linewidth": 1,
+      "links": [],
+      "nullPointMode": "null",
+      "options": {
+        "alertThreshold": true
+      },
+      "paceLength": 10,
+      "percentage": false,
+      "pluginVersion": "9.5.2",
+      "pointradius": 2,
+      "points": false,
+      "renderer": "flot",
+      "seriesOverrides": [],
+      "spaceLength": 10,
+      "stack": false,
+      "steppedLine": false,
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "KNkR71YVk"
+          },
+          "exemplar": true,
+          "expr": "process_resident_memory_bytes{job=\"hedgedoc\"}",
+          "format": "time_series",
+          "interval": "",
+          "intervalFactor": 1,
+          "legendFormat": "Process Memory",
+          "refId": "A"
+        },
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "KNkR71YVk"
+          },
+          "exemplar": true,
+          "expr": "nodejs_heap_size_total_bytes{job=\"hedgedoc\"}",
+          "format": "time_series",
+          "interval": "",
+          "intervalFactor": 1,
+          "legendFormat": "Heap Total ",
+          "refId": "B"
+        },
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "KNkR71YVk"
+          },
+          "exemplar": true,
+          "expr": "nodejs_heap_size_used_bytes{job=\"hedgedoc\"}",
+          "format": "time_series",
+          "interval": "",
+          "intervalFactor": 1,
+          "legendFormat": "Heap Used",
+          "refId": "C"
+        },
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "KNkR71YVk"
+          },
+          "exemplar": true,
+          "expr": "nodejs_external_memory_bytes{job=\"hedgedoc\"}",
+          "format": "time_series",
+          "interval": "",
+          "intervalFactor": 1,
+          "legendFormat": "External Memory - {{instance}}",
+          "refId": "D"
+        }
+      ],
+      "thresholds": [],
+      "timeRegions": [],
+      "title": "Process Memory Usage",
+      "tooltip": {
+        "shared": true,
+        "sort": 0,
+        "value_type": "individual"
+      },
+      "type": "graph",
+      "xaxis": {
+        "mode": "time",
+        "show": true,
+        "values": []
+      },
+      "yaxes": [
+        {
+          "$$hashKey": "object:267",
+          "format": "bytes",
+          "logBase": 1,
+          "show": true
+        },
+        {
+          "$$hashKey": "object:268",
+          "format": "short",
+          "logBase": 1,
+          "show": true
+        }
+      ],
+      "yaxis": {
+        "align": false
+      }
+    },
+    {
+      "aliasColors": {},
+      "bars": false,
+      "dashLength": 10,
+      "dashes": false,
+      "datasource": {
+        "type": "prometheus",
+        "uid": "KNkR71YVk"
+      },
+      "fill": 1,
+      "fillGradient": 0,
+      "gridPos": {
+        "h": 7,
+        "w": 8,
+        "x": 16,
+        "y": 21
+      },
+      "hiddenSeries": false,
+      "id": 14,
+      "legend": {
+        "alignAsTable": true,
+        "avg": true,
+        "current": true,
+        "max": true,
+        "min": true,
+        "show": true,
+        "total": false,
+        "values": true
+      },
+      "lines": true,
+      "linewidth": 1,
+      "links": [],
+      "nullPointMode": "null",
+      "options": {
+        "alertThreshold": true
+      },
+      "paceLength": 10,
+      "percentage": false,
+      "pluginVersion": "9.5.2",
+      "pointradius": 2,
+      "points": false,
+      "renderer": "flot",
+      "seriesOverrides": [],
+      "spaceLength": 10,
+      "stack": false,
+      "steppedLine": false,
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "KNkR71YVk"
+          },
+          "exemplar": true,
+          "expr": "nodejs_active_handles_total{job=\"hedgedoc\"}",
+          "format": "time_series",
+          "interval": "",
+          "intervalFactor": 1,
+          "legendFormat": "Active Handler ",
+          "refId": "A"
+        },
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "KNkR71YVk"
+          },
+          "exemplar": true,
+          "expr": "nodejs_active_requests_total{job=\"hedgedoc\"}",
+          "format": "time_series",
+          "interval": "",
+          "intervalFactor": 1,
+          "legendFormat": "Active Request",
+          "refId": "B"
+        }
+      ],
+      "thresholds": [],
+      "timeRegions": [],
+      "title": "Active Handlers/Requests Total",
+      "tooltip": {
+        "shared": true,
+        "sort": 0,
+        "value_type": "individual"
+      },
+      "type": "graph",
+      "xaxis": {
+        "mode": "time",
+        "show": true,
+        "values": []
+      },
+      "yaxes": [
+        {
+          "$$hashKey": "object:323",
+          "format": "short",
+          "logBase": 1,
+          "show": true
+        },
+        {
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