Fix for mountstats error due to multiline "impl_id" on FreeNAS (prometheus#339)

* Fix for mountstats error due to multiline "impl_id" on FreeNAS
This commit fixes an error happening when trying to parse data from FreeNAS NFS
mount point. "impl_id" is printed in multiple lines, which triggers "not enough
information for NFS stats" error.

Signed-off-by: Jakub Wesolowski <[email protected]>

Author: JakubWes

mountstats.go

@@ -338,12 +338,12 @@ func parseMountStatsNFS(s *bufio.Scanner, statVersion string) (*MountStatsNFS, e
 		if len(ss) == 0 {
 			break
 		}
-		if len(ss) < 2 {
-			return nil, fmt.Errorf("not enough information for NFS stats: %v", ss)
-		}
 
 		switch ss[0] {
 		case fieldOpts:
+			if len(ss) < 2 {
+				return nil, fmt.Errorf("not enough information for NFS stats: %v", ss)
+			}
 			if stats.Opts == nil {
 				stats.Opts = map[string]string{}
 			}
@@ -356,6 +356,9 @@ func parseMountStatsNFS(s *bufio.Scanner, statVersion string) (*MountStatsNFS, e
 				}
 			}
 		case fieldAge:
+			if len(ss) < 2 {
+				return nil, fmt.Errorf("not enough information for NFS stats: %v", ss)
+			}
 			// Age integer is in seconds
 			d, err := time.ParseDuration(ss[1] + "s")
 			if err != nil {
@@ -364,13 +367,19 @@ func parseMountStatsNFS(s *bufio.Scanner, statVersion string) (*MountStatsNFS, e
 
 			stats.Age = d
 		case fieldBytes:
+			if len(ss) < 2 {
+				return nil, fmt.Errorf("not enough information for NFS stats: %v", ss)
+			}
 			bstats, err := parseNFSBytesStats(ss[1:])
 			if err != nil {
 				return nil, err
 			}
 
 			stats.Bytes = *bstats
 		case fieldEvents:
+			if len(ss) < 2 {
+				return nil, fmt.Errorf("not enough information for NFS stats: %v", ss)
+			}
 			estats, err := parseNFSEventsStats(ss[1:])
 			if err != nil {
 				return nil, err

mountstats_test.go

@@ -64,7 +64,7 @@ func TestMountStats(t *testing.T) {
 		},
 		{
 			name:    "NFSv4 device with too little info",
-			s:       "device 192.168.1.1:/srv mounted on /mnt/nfs with fstype nfs4 statvers=1.1\nhello",
+			s:       "device 192.168.1.1:/srv mounted on /mnt/nfs with fstype nfs4 statvers=1.1\nopts:",
 			invalid: true,
 		},
 		{
@@ -253,6 +253,26 @@ func TestMountStats(t *testing.T) {
 				},
 			}},
 		},
+		{
+			name: "NFS4.1 device with multiline impl_id OK",
+			s:    "device 192.168.0.1:/srv mounted on /mnt/nfs with fstype nfs4 statvers=1.1\nopts: rw,vers=4.1,rsize=131072,wsize=131072,namlen=255,acregmin=3,acregmax=60,acdirmin=30,acdirmax=60,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.0.2,fsc,local_lock=none\nage: 1234567\nimpl_id: name='FreeBSD 11.2-STABLE #0 r325575+c9231c7d6bd(HEAD): Mon Nov 18 22:46:47 UTC 2019\nuser@host:/path/to/something'\n,domain='something.org',date='1293840000,0'",
+			mounts: []*Mount{{
+				Device: "192.168.0.1:/srv",
+				Mount:  "/mnt/nfs",
+				Type:   "nfs4",
+				Stats: &MountStatsNFS{
+					StatVersion: "1.1",
+					Opts: map[string]string{"rw": "", "vers": "4.1",
+						"rsize": "131072", "wsize": "131072", "namlen": "255", "acregmin": "3",
+						"acregmax": "60", "acdirmin": "30", "acdirmax": "60", "fsc": "", "hard": "",
+						"proto": "tcp", "timeo": "600", "retrans": "2",
+						"sec": "sys", "clientaddr": "192.168.0.2",
+						"local_lock": "none",
+					},
+					Age: 1234567 * time.Second,
+				},
+			}},
+		},
 		{
 			name: "fixtures/proc OK",
 			mounts: []*Mount{