Seed RNG to ensure different ICMP ids. (#638)

Fixes #632

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

diff --git a/prober/icmp.go b/prober/icmp.go
index 83c8736b76c53a2147669c49ba83931e80e6f074..565988dd562182c07064c7d9654ce75e22c2f98d 100644 (file)
--- a/prober/icmp.go
+++ b/prober/icmp.go
@@ -39,11 +39,12 @@ var (
 )
 
 func init() {
+       r := rand.New(rand.NewSource(time.Now().UnixNano()))
        // PID is typically 1 when running in a container; in that case, set
        // the ICMP echo ID to a random value to avoid potential clashes with
        // other blackbox_exporter instances. See #411.
        if pid := os.Getpid(); pid == 1 {
-               icmpID = rand.Intn(1 << 16)
+               icmpID = r.Intn(1 << 16)
        } else {
                icmpID = pid & 0xffff
        }
@@ -51,7 +52,7 @@ func init() {
        // Start the ICMP echo sequence at a random offset to prevent them from
        // being in sync when several blackbox_exporter instances are restarted
        // at the same time. See #411.
-       icmpSequence = uint16(rand.Intn(1 << 16))
+       icmpSequence = uint16(r.Intn(1 << 16))
 }
 
 func getICMPSequence() uint16 {