Adds a "type" field to the filesystem beat

[cv]

Its value is copied from sigar.FileSystem.SysTypeName and passed through so that it becomes possible to filter out overlay, tmpfs or otherwise uninteresting filesystems.

Fixes #3459.

[elasticmachine]

Can one of the admins verify this patch?

[elasticmachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically on build-eu-00. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[tsg]

@cv Thanks for working on this. Run make update to solve the check failure.

[cv]

@tsg you're most welcome, and I'm sorry I can't seem to fix the build breakage through make update. I'm still pretty unfamiliar with the build/doc system, so do you have any pointers?

[tsg]

When I run make update top level in your branch, it modifies two files:

	modified:   libbeat/_meta/kibana/5.x/index-pattern/libbeat.json
	modified:   libbeat/_meta/kibana/default/index-pattern/libbeat.json

Do you get the same? Or some error during make update?

[tsg]

make update is our one command to re-create all generated files (includes the notice file, the docs, etc.)

[cv]

Oh, this could be it. I get no changes when I run it. Could it be an env difference?

Output: https://gist.github.com/cv/4b596841382fb6d4193a86d95ba05d38

[tsg]

Can you try a rebase to master (make sure master is up to date, then git rebase master) and them make update again?

[cv]

Done… still, no files get updated. I'm going to set up a Linux build environment to see if there are any differences.

[cv]

Ok, so when running on Linux (a little docker image did the job), the files do get updated and I get the same result as you, @tsg. I'm wondering why the builds failed even so, as nothing in the output immediately jumps at me.

[tsg]

jenkins, test it

[tsg]

@cv Travis is green now, we had some issues lately with Travis timing out on some of our stuff, so it's flaky at the moment. We're looking for solutions.

[tsg]

@cv can you add a line in the CHANGELOG.asciidoc file, please?

[tsg]

I'm thinking if we shouldn't name this simpler as system.filesystem.type. I usually think of ext4 (for example) as a filesystem type, so that seems to fit. device_type, on the other had, makes me think of hardware.

[cv]

Good rationale. I'll change it in a few minutes.

[cv]

This last build looks like the least fail-y so far :)

@tsg, I'd say work here is done, and unless you have any other points you'd like me to work on, can I clean up / rebase the commit history? Or do you typically do that when squashing into master?

[tsg]

@cv Yes, please rebase & squash. I'd do it on merging, but now there's a conflict anyway. Thanks a lot for your work!

[cv]

All squashed (except for the merge conflict fix, which I left as its own commit so it can be reviewed).