Mount info gatherer

[arbulu89]

Add mount_info gatherer. This gatherer returns if a given path is mounted, and its information. Besides that, in case of mounted, it returns the blkid UUID value of that block.

The path to check is the required argument.

If it is not mounted, it returns all the fields as empty string. I needed to do so, because checking if a path (/usr/sap) is not mounted (or it is directly in the root folder` is the main reason this gatherer exists.

If the path is mounted in nfs-kind of sharing system, the block_uuid comes empty

Some outputs:

// trento-agent facts gather --gatherer mount_info --argument /usr/sap
#{
  "block_uuid": "f45cf408-efgh-abcd-88ec-2f9269a12f07",
  "fs_type": "xfs",
  "mount_point": "/usr/sap",
  "options": "rw,relatime",
  "source": "/dev/mapper/vg_hana_usrsap-lv_hana_usrsap_0"
} 

// trento-agent facts gather --gatherer mount_info --argument /sapmnt
#{
  "block_uuid": "",
  "fs_type": "cifs",
  "mount_point": "/sapmnt",
  "options": "rw,relatime",
  "source": "10.1.1.10://sapmnt"
} 

[abravosuse]

The output looks good to me @arbulu89

[rtorrero]

Perfect @arbulu89, great work! left some thoughts in the comments but no need to do anything about them

[rtorrero]

I've noticed that sometimes we use the same checkid for factrequests in the tests, while other times we put incrementally increased ones and sometimes we don't put it at all. Should we apply some logic when doing so? if on the contrary, it doesn't matter at all for the tests, should we better just remove it?

No need to change anything, just wondering about this.

[arbulu89]

It is true that it doesn't add a lot of real value. This is already tested in other places. At most, if you don't use the NewFactGatheredWithRequest, it could fail, as you forgot to pass the check id.
For me it is a good practice, as the CheckID is a mandatory field for our contract data

[rtorrero]

For now, this is perfect IMHO, in the future if we want to also detect more complex scenarios we could decompose the mountpoint when it's not found and test backwards if the parent exists, e.g. /usr/sap passed as argument would first need to check /usr/sap and if doesn't find it, it would check /usr and if not found, it could then fallback to / and just return the details stating in mount_point the parent mountpoint of that path.

[arbulu89]

Let's see if we have such a requirement hehe

[EMaksy]

Hey man codewise lgtm :)