Title
#general
r

Ryan

11/05/2021, 3:38 PM
Does anyone know if there’s a lightweight way to query host metadata from, say, a YAML file on a host or something similar?
3:38 PM
An example could be metadata about a host that is generated at provisioning time, and written to a file on the host somewhere, that we could query as a table?
Gavin

Gavin

11/05/2021, 3:39 PM
r

Ryan

11/05/2021, 3:39 PM
intriguing
3:39 PM
thanks for the suggestion!
f

fritz

11/05/2021, 4:02 PM
@Ryan If you do not want to deal with an extension you could simply write the metadata to a plist and use the built-in
plist
table
4:03 PM
If you need it to be multi-platform you can create an augeas lens and ship that lens to your devices.
r

Ryan

11/05/2021, 4:03 PM
Ah that’s a nice one to know too, though these are Linux machines, not Mac.
f

fritz

11/05/2021, 4:03 PM
Another multi-platform option is encode the data in a sqlite db and then create an ATC for that DB file
r

Ryan

11/05/2021, 4:03 PM
Do you have any examples of an Augeas lens?
f

fritz

11/05/2021, 4:04 PM
The ATC is probably the most simple option that is multi-platform
r

Ryan

11/05/2021, 4:04 PM
ah yeah, just reading about that now
4:04 PM
very interesting!
4:04 PM
thanks!
f

fritz

11/05/2021, 4:04 PM
r

Ryan

11/05/2021, 4:05 PM
haha yes that’s the one I was reading 😄
f

fritz

11/05/2021, 4:05 PM
😜 You beat me to it!
4:05 PM
Good luck, let me know if you have any questions.
r

Ryan

11/05/2021, 4:05 PM
heheh
4:05 PM
thanks, yeah this looks very powerful/flexible
defensivedepth

defensivedepth

11/05/2021, 7:56 PM
If you are just targeting Linux, you could write out the info you need to a sysctl parameter at deployment and then query it with the https://osquery.io/schema/5.0.1/#system_controls table
8:09 PM
To be clear, havent tried it myself but I would think it should work
s

seph

11/06/2021, 2:58 AM
Or use a directory with cleverly named files as a rudimentary key/value store.
2:59 AM
There are some ways you can get pretty clever
Mystery Incorporated

Mystery Incorporated

11/08/2021, 2:10 AM
Environment variables also work to stash and retrieve stuff but might not be great if you have a lot of stuff
r

Ryan

11/08/2021, 11:45 AM
Environment variables? Do you have an example of that approach?
Mystery Incorporated

Mystery Incorporated

11/08/2021, 12:24 PM
Yup I put some values in environment variables and I have queries like:
Windows: SELECT value FROM default_environment WHERE variable LIKE "%environment_variable_name_here%" LIMIT 1
Ubuntu/Centos/Darwin: SELECT value FROM process_envs WHERE key LIKE "%environment_variable_name_here%" LIMIT 1
12:25 PM
So I can set these environment variables on any device and fetch them with a query, if you control the metadata you would write it to envars instead of a file and fetch like that easy enough, but I don't know if there is size limits or what.
12:32 PM
This allows me to tag my hosts with like a company id and such that I can query. I then put the company name in a decorator query so I know which company the host belongs to for every query it responds to.
r

Ryan

11/09/2021, 2:49 PM
Ok, sounds interesting!
2:50 PM
When you talk about decorator queries, that’s the same as creating a label in Fleet interface or via Fleetctl right?
Mystery Incorporated

Mystery Incorporated

11/16/2021, 12:31 AM
@Ryan nah labels in fleet return groups of hosts. A decorator query in osquery is a query that executes with every single query so for every query in my case it returns username, hostname and company name fetched from the envvar and it includes that with every single query executed
r

Ryan

11/23/2021, 3:23 PM
ahhh right, gotcha @Mystery Incorporated that’s very handy actually 🙂