1. docker
  2. Commit c7b1e5ba3829a1690a732c19c20d5bf48d58b0d2
Browse code

portallocator: log instead of discard port-range failures

Both getDynamicPortRange() and sanitizePortRange() could produce
and error, and the error message was currently discarded, silently
falling back to using the default port range.

This patch:

- Moves the fallback message from getDynamicPortRange() to getDefaultPortRange(),
which is where the actual fallback occurs.
- Logs the fallback message and the error that causes the fallback.

The message/error is currently printed at the INFO level, but could be raised
to a WARN, depending on what kind of situations can cause the error.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Sebastiaan van Stijn authored on 2020/09/24 18:09:34
Showing 3 changed files
libnetwork/portallocator/portallocator.go
History View file @ c7b1e5b
... ... 
@@ -110,6 +110,7 @@ func getDefaultPortRange() (int, int) {
110 110 
 		start, end, err = sanitizePortRange(start, end)
111 111 
 	}
112 112 
 	if err != nil {
113 
+		logrus.WithError(err).Infof("falling back to default port range %d-%d", defaultPortRangeStart, defaultPortRangeEnd)
113 114 
 		start, end = defaultPortRangeStart, defaultPortRangeEnd
114 115 
 	}
115 116 
 	return start, end
libnetwork/portallocator/portallocator_freebsd.go
History View file @ c7b1e5b
... ... 
@@ -8,20 +8,19 @@ import (
8 8
9 9 
 func getDynamicPortRange() (start int, end int, err error) {
10 10 
 	portRangeKernelSysctl := []string{"net.inet.ip.portrange.hifirst", "net.ip.portrange.hilast"}
11 
-	portRangeFallback := fmt.Sprintf("using fallback port range %d-%d", defaultPortRangeStart, defaultPortRangeEnd)
12 11 
 	portRangeLowCmd := exec.Command("/sbin/sysctl", portRangeKernelSysctl[0])
13 12 
 	var portRangeLowOut bytes.Buffer
14 13 
 	portRangeLowCmd.Stdout = &portRangeLowOut
15 14 
 	cmdErr := portRangeLowCmd.Run()
16 15 
 	if cmdErr != nil {
17 
-		return 0, 0, fmt.Errorf("port allocator - sysctl net.inet.ip.portrange.hifirst failed - %s: %v", portRangeFallback, err)
16 
+		return 0, 0, fmt.Errorf("port allocator - sysctl net.inet.ip.portrange.hifirst failed: %v", err)
18 17 
 	}
19 18 
 	n, err := fmt.Sscanf(portRangeLowOut.String(), "%d", &start)
20 19 
 	if n != 1 || err != nil {
21 20 
 		if err == nil {
22 21 
 			err = fmt.Errorf("unexpected count of parsed numbers (%d)", n)
23 22 
 		}
24 
-		return 0, 0, fmt.Errorf("port allocator - failed to parse system ephemeral port range start from %s - %s: %v", portRangeLowOut.String(), portRangeFallback, err)
23 
+		return 0, 0, fmt.Errorf("port allocator - failed to parse system ephemeral port range start from %s: %v", portRangeLowOut.String(), err)
25 24 
 	}
26 25
27 26 
 	portRangeHighCmd := exec.Command("/sbin/sysctl", portRangeKernelSysctl[1])
... ... 
@@ -29,14 +28,14 @@ func getDynamicPortRange() (start int, end int, err error) {
29 29 
 	portRangeHighCmd.Stdout = &portRangeHighOut
30 30 
 	cmdErr = portRangeHighCmd.Run()
31 31 
 	if cmdErr != nil {
32 
-		return 0, 0, fmt.Errorf("port allocator - sysctl net.inet.ip.portrange.hilast failed - %s: %v", portRangeFallback, err)
32 
+		return 0, 0, fmt.Errorf("port allocator - sysctl net.inet.ip.portrange.hilast failed: %v", err)
33 33 
 	}
34 34 
 	n, err = fmt.Sscanf(portRangeHighOut.String(), "%d", &end)
35 35 
 	if n != 1 || err != nil {
36 36 
 		if err == nil {
37 37 
 			err = fmt.Errorf("unexpected count of parsed numbers (%d)", n)
38 38 
 		}
39 
-		return 0, 0, fmt.Errorf("port allocator - failed to parse system ephemeral port range end from %s - %s: %v", portRangeHighOut.String(), portRangeFallback, err)
39 
+		return 0, 0, fmt.Errorf("port allocator - failed to parse system ephemeral port range end from %s: %v", portRangeHighOut.String(), err)
40 40 
 	}
41 41 
 	return start, end, nil
42 42 
 }
libnetwork/portallocator/portallocator_linux.go
History View file @ c7b1e5b
... ... 
@@ -8,12 +8,10 @@ import (
8 8
9 9 
 func getDynamicPortRange() (start int, end int, err error) {
10 10 
 	const portRangeKernelParam = "/proc/sys/net/ipv4/ip_local_port_range"
11 
-	portRangeFallback := fmt.Sprintf("using fallback port range %d-%d", defaultPortRangeStart, defaultPortRangeEnd)
12 11 
 	file, err := os.Open(portRangeKernelParam)
13 12 
 	if err != nil {
14 
-		return 0, 0, fmt.Errorf("port allocator - %s due to error: %v", portRangeFallback, err)
13 
+		return 0, 0, err
15 14 
 	}
16 
-
17 15 
 	defer file.Close()
18 16
19 17 
 	n, err := fmt.Fscanf(bufio.NewReader(file), "%d\t%d", &start, &end)
... ... 
@@ -21,7 +19,7 @@ func getDynamicPortRange() (start int, end int, err error) {
21 21 
 		if err == nil {
22 22 
 			err = fmt.Errorf("unexpected count of parsed numbers (%d)", n)
23 23 
 		}
24 
-		return 0, 0, fmt.Errorf("port allocator - failed to parse system ephemeral port range from %s - %s: %v", portRangeKernelParam, portRangeFallback, err)
24 
+		return 0, 0, fmt.Errorf("port allocator - failed to parse system ephemeral port range from %s: %v", portRangeKernelParam, err)
25 25 
 	}
26 26 
 	return start, end, nil
27 27 
 }