From ece07b36fcc3cf59b37040213345887eeb860ad7 Mon Sep 17 00:00:00 2001
From: Christian Pointner <equinox@spreadspace.org>
Date: Sun, 16 Jul 2023 17:36:47 +0200
Subject: [PATCH] Add a command line option to force chmod on the receiving
 unix socket. (#45)

fixes #44

Signed-off-by: Christian Pointner <equinox@spreadspace.org>
---
 README.md              |  1 +
 collector/collector.go | 20 ++++++++++++++------
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index a503994..44392c2 100644
--- a/README.md
+++ b/README.md
@@ -60,6 +60,7 @@ By default, the exporter will bind on `:9123`.
 In case chrony is configured to not accept command messages via UDP (`cmdport 0`) the exporter can use the unix command socket opened by chrony.
 In this case use the command line option `--chrony.address=unix:///path/to/chronyd.sock` to configure the path to the chrony command socket.
 On most systems chrony will be listenting on `unix:///run/chrony/chronyd.sock`. For this to work the exporter needs to run as root or the same user as chrony.
+When the exporter is run as root the flag `collector.chmod-socket` is needed as well.
 
 ## Prometheus Rules
 
diff --git a/collector/collector.go b/collector/collector.go
index 9d9d8d2..654b4dc 100644
--- a/collector/collector.go
+++ b/collector/collector.go
@@ -33,8 +33,9 @@ const (
 )
 
 var (
-	collectTracking = kingpin.Flag("collector.tracking", "Collect tracking metrics").Default("true").Bool()
-	collectSources  = kingpin.Flag("collector.sources", "Collect sources metrics").Default("false").Bool()
+	collectTracking    = kingpin.Flag("collector.tracking", "Collect tracking metrics").Default("true").Bool()
+	collectSources     = kingpin.Flag("collector.sources", "Collect sources metrics").Default("false").Bool()
+	collectChmodSocket = kingpin.Flag("collector.chmod-socket", "Chmod 0666 the receiving unix datagram socket").Default("false").Bool()
 
 	upMetric = typedDesc{
 		prometheus.NewDesc(
@@ -53,8 +54,9 @@ type Exporter struct {
 	address string
 	timeout time.Duration
 
-	collectSources  bool
-	collectTracking bool
+	collectSources     bool
+	collectTracking    bool
+	collectChmodSocket bool
 
 	logger log.Logger
 }
@@ -74,8 +76,9 @@ func NewExporter(address string, logger log.Logger) Exporter {
 		address: address,
 		timeout: 5 * time.Second,
 
-		collectSources:  *collectSources,
-		collectTracking: *collectTracking,
+		collectSources:     *collectSources,
+		collectTracking:    *collectTracking,
+		collectChmodSocket: *collectChmodSocket,
 
 		logger: logger,
 	}
@@ -97,6 +100,11 @@ func (e Exporter) dial() (net.Conn, error, func()) {
 		if err != nil {
 			return nil, err, func() { os.Remove(local) }
 		}
+		if e.collectChmodSocket {
+			if err := os.Chmod(local, 0666); err != nil {
+				return nil, err, func() { conn.Close(); os.Remove(local) }
+			}
+		}
 		err = conn.SetReadDeadline(time.Now().Add(e.timeout))
 		if err != nil {
 			level.Debug(e.logger).Log("msg", "Couldn't set read-timeout for unix datagram socket", "err", err)