fix: log each agent message once, and skip untracked sockets before the map lookup

containers/container.go

@@ -829,6 +829,13 @@ func (c *Container) createConnectionFromSocketInfo(pid uint32, fd uint64, timest
 	if socketInfo == nil || !socketInfo.Valid {
 		return nil, false
 	}
+	// connectionKey applies the same filter below; checking it first skips
+	// the parsing and the kernel map lookup for the commonest case. A TLS
+	// server's accepted sockets have a client's ephemeral port as their
+	// destination, are never tracked, and come through here on every event.
+	if common.PortFilter.ShouldBeSkipped(socketInfo.DstPort) {
+		return nil, true
+	}
 
 	// Parse destination IP
 	dstIP, err := netaddr.ParseIP(socketInfo.DstIP)

main.go

@@ -164,6 +164,10 @@ func main() {
 	flag.Set("logtostderr", "false")
 	flag.Set("alsologtostderr", "false")
 	flag.Set("stderrthreshold", "FATAL")
+	// SetOutput gives every severity the same writer, and klog writes a
+	// message to its own severity's writer and every lower one's: without
+	// one_output each warning was logged twice and each error three times.
+	flag.Set("one_output", "true")
 	klog.SetOutput(&RateLimitedLogOutput{limiter: rate.NewLimiter(rate.Limit(*flags.LogPerSecond), *flags.LogBurst)})
 
 	klog.Infoln("agent version:", version)