From ed0fcb59eb4f4dc53759585ddde68ab8da190be5 Mon Sep 17 00:00:00 2001
From: HeshamTB <hishaminv@gmail.com>
Date: Tue, 19 Mar 2024 02:56:52 +0300
Subject: [PATCH] feat: monitor peers in logs, README, Status

Signed-off-by: HeshamTB <hishaminv@gmail.com>
---
 README.md                  |  5 +++-
 cmd/hvpn-node/hvpn-node.go |  2 ++
 const.go                   |  5 ++++
 handlers.go                | 17 +++++------
 monitor.go                 | 61 ++++++++++++++++++++++++++++++++++++++
 5 files changed, 79 insertions(+), 11 deletions(-)
 create mode 100644 const.go
 create mode 100644 monitor.go

diff --git a/README.md b/README.md
index e80d038..a02ce1a 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,8 @@
 # hvpn-node3
-
+hvpn is a basic HTTP API service that manages wireguard VPN. Can be part of part of
+a larger system of services. The program itself does not route and manage the
+VPN traffic; but the underlying host and kernel wiregaurd driver. hvpn only
+exposes the state and allows changes to be applied.
 ## Build
 ```bash
 cd cmd/hvpn-node && go build .
diff --git a/cmd/hvpn-node/hvpn-node.go b/cmd/hvpn-node/hvpn-node.go
index fbc1654..51580c2 100644
--- a/cmd/hvpn-node/hvpn-node.go
+++ b/cmd/hvpn-node/hvpn-node.go
@@ -55,6 +55,8 @@ func main() {
 func run(ctx *cli.Context) {
     slog.Debug("Starting run()")
 
+    hvpnnode3.StartMonitor(wgLink, *slog.Default())
+
     apiMux := http.NewServeMux()
     apiMux.HandleFunc("GET /node", hvpnnode3.HandleGetNodeInfo(wgLink))
     apiMux.HandleFunc("GET /peer/{pubkey}", hvpnnode3.HandleGetPeer(wgLink))
diff --git a/const.go b/const.go
new file mode 100644
index 0000000..0b8f1c5
--- /dev/null
+++ b/const.go
@@ -0,0 +1,5 @@
+package hvpnnode3
+
+const (
+    CONTENT_JSON = "application/json"
+)
diff --git a/handlers.go b/handlers.go
index 2040a5e..6b22a4b 100644
--- a/handlers.go
+++ b/handlers.go
@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"log/slog"
 	"net/http"
+	"net/url"
 
 	"github.com/felixge/httpsnoop"
 	"github.com/google/uuid"
@@ -119,15 +120,8 @@ func HandlePostPeer(wgLink *WGLink) http.HandlerFunc {
         }
         if exists {
             debugf("Peer %s already exists", reqID, peerRequest.PublicKey)
-            w.WriteHeader(http.StatusFound)
-            peer, err := wgLink.GetPeer(peerRequest.PublicKey)
-            if err != nil {
-                slog.Error(err.Error())
-                return
-            }
-            json.NewEncoder(w).Encode(
-                proto.WgPeerToPeer(*peer),
-            )
+            w.Header().Add("Location", fmt.Sprintf("/peer/%s", url.QueryEscape(peerRequest.PublicKey)))
+            w.WriteHeader(http.StatusConflict)
             return
         }
 
@@ -140,7 +134,9 @@ func HandlePostPeer(wgLink *WGLink) http.HandlerFunc {
             )
             return
         }
-        debugf("Allocated IP: %s", reqID, peer.AllowedIPs[0].IP.String())
+        infof("Allocated IP: %s", reqID, peer.AllowedIPs[0].IP.String())
+        infof("Peer %s added", reqID, peerRequest.PublicKey)
+        w.Header().Set("Content-Type", CONTENT_JSON)
         w.WriteHeader(http.StatusCreated)
         json.NewEncoder(w).Encode(
             proto.WgPeerToPeer(*peer),
@@ -174,6 +170,7 @@ func HandleDeletePeer(wg *WGLink) http.HandlerFunc {
             )
             slog.Error(err.Error())
         }
+        w.WriteHeader(http.StatusNoContent)
     }
 }
 
diff --git a/monitor.go b/monitor.go
new file mode 100644
index 0000000..aca52c2
--- /dev/null
+++ b/monitor.go
@@ -0,0 +1,61 @@
+package hvpnnode3
+
+import (
+	"fmt"
+	"log/slog"
+	"strings"
+	"time"
+
+	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
+)
+
+var log slog.Logger
+
+func StartMonitor(wg *WGLink, log slog.Logger) {
+    go monitor(wg, log)
+}
+
+func monitor(wg *WGLink, log slog.Logger) {
+    log.Info("[WGMonitor] Starting")
+    for {
+        time.Sleep(time.Second * 5)
+        peers, err := wg.GetAllPeers()
+        if err != nil {
+            log.Error("[WGMonitor] " + err.Error())
+            continue
+        }
+
+        activepeers, err := getActivePeers(peers)
+        if err != nil {
+            log.Error("[WGMonitor] " + err.Error())
+            continue
+        }
+
+        sb := strings.Builder{}
+        sb.WriteString(fmt.Sprintf("Peers: %d ", len(peers)))
+        sb.WriteString(fmt.Sprintf("Active peers: %d ", len(activepeers)))
+
+        var totalRx int64
+        var totalTx int64
+        for _, peer := range activepeers {
+            totalRx += peer.ReceiveBytes
+            totalTx += peer.TransmitBytes
+        }
+        sb.WriteString(fmt.Sprintf("TX: %d RX: %d", totalTx, totalRx))
+
+        log.Info("[WGMonitor] " + sb.String())
+    }
+}
+
+func getActivePeers(peers []wgtypes.Peer) ([]wgtypes.Peer, error) {
+    active := make([]wgtypes.Peer, 0)
+    for _, peer := range peers {
+        if peer.LastHandshakeTime.IsZero() {
+            continue
+        } else if time.Now().UTC().Sub(peer.LastHandshakeTime.UTC()) < time.Duration(4 * time.Minute) {
+            active = append(active, peer)
+        }
+    }
+    return active, nil
+}
+