We must know the length of the various filesystem C strings before
turning them from a byte array into a Go string, otherwise our Go
strings could contain null bytes, corrupting the label values.
Signed-off-by: David O'Rourke <david.orourke@gmail.com>
Named return variables should only be used to describe the returned type
further, e.g. `err error` doesn't add any new information and is just
stutter.
When compiling `20ecedd0b4c983bd7b88f97cd7a21461988a6c12` with GNU make (`gmake`) on FreeBSD 10.2-RELEASE, I get the following error:
```
collector/filesystem_bsd.go:60: non-bool mnt[i].f_flags & MNT_RDONLY (type C.uint64_t) used as if condition
Makefile.COMMON:85: recipe for target 'node_exporter' failed
gmake: *** [node_exporter] Error 2
```
This problem is fixed by this patch.
When compiling `20ecedd0b4c983bd7b88f97cd7a21461988a6c12` with GNU make (`gmake`) on FreeBSD 10.2-RELEASE, I get the following error:
```
collector/filesystem_bsd.go:60: non-bool mnt[i].f_flags & MNT_RDONLY (type C.uint64_t) used as if condition
Makefile.COMMON:85: recipe for target 'node_exporter' failed
gmake: *** [node_exporter] Error 2
```
This problem is fixed by this patch.
Collects more information for labelling scraped filesystems with the device
and fsType. This is useful for setting alerts which should change based on
filesystem type, or for filtering out shared mounts such as with NFS volumes.
This puts all collector-specific flags into their own namespace under
"collector.<collector-name>", and moves from camel case to dashes, which
is the standard in Prometheus land now.
Switch to Update using the Collecter Collect interface, due to not knowing all
metricnames in all modules beforehand we can't use Describe and thus the full
Collecter interface.
Remove 'updates', it's meaning varies by module and doesn't add much.
David O'Rourke