Getting Data In

Inputlookup subsearch to match on field A and output field B in CSV file

christoffertoft
Communicator

Im trying to correlate info based on a lookup file and no matter how I try, I cant make it work.

I have a CSV with values like:

host,country
host1*,country1
host2*,country1
host3*,country2

etc

Im running a search that outputs hosts using a regex:
... | rex field=field1 //Simplified, extracts host from text
| [|inputlookup csvfile.csv ]
| bucket _time span=30d
| stats list(host), list(country) by _time

This search of course does not work.
I want to match the host field of the csv with the rexed host from the search and get the country the host is in in a list along with the actual host.

I've tried numerous ways but cannot get it to work. Some help would be greatly appreciated. How do I make sure to match the rexed host with a host* value in the csv?

0 Karma
1 Solution

gcusello
SplunkTrust
SplunkTrust

Hi christoffertoft,
in your lookup don't use * but insert a row for each host

host,country
host1,country1
host2,country1
host3,country3
host4,country2
...

then try a search like this:

my_search
| rex "//Simplified"
| dedup host
| lookup csvfile.csv host OUTPUT country
| table host country

If you have more that 10,000 hosts use dedup 0 host.

Bye.
Giuseppe

View solution in original post

gcusello
SplunkTrust
SplunkTrust

Hi christoffertoft,
in your lookup don't use * but insert a row for each host

host,country
host1,country1
host2,country1
host3,country3
host4,country2
...

then try a search like this:

my_search
| rex "//Simplified"
| dedup host
| lookup csvfile.csv host OUTPUT country
| table host country

If you have more that 10,000 hosts use dedup 0 host.

Bye.
Giuseppe

christoffertoft
Communicator

Hi Giuseppe,
I need to have host* entries because there are a too wide variety of possible names for me to catalogue. I only need to match the first part of the host anyway. Does this make a difference? Thanks for your reply

0 Karma

christoffertoft
Communicator

Basically, I know that ABC123 and ABC456 belongs to a specific country and thus i only need to match on ABC.
If it was DEF123 i would now it was another country. As such, I can say ABC*=country1, DEF*=country2.

0 Karma

gcusello
SplunkTrust
SplunkTrust

Hi christoffertoft,
so you can build your lookup

class_host,country
ABC,country1
DEF,country2
GHI,country3

and run this search

 my_search
 | rex "//Simplified"
 | eval class_host=substr(host,1,3)
 | lookup csvfile.csv class_host OUTPUT country
 | dedup host
 | table host country

Bye.
Giuseppe

0 Karma

christoffertoft
Communicator

Right, I will try this! Thanks alot for the help

0 Karma

gcusello
SplunkTrust
SplunkTrust

If you're satisfied, please accept or upvote this answer.
Bye.
Giuseppe

0 Karma

gcusello
SplunkTrust
SplunkTrust

Hi christoffertoft,
lookup command matches only the full string, not *.
but if you can define a rule (e.g.: first 4 chars of hostname) you could build your lookup in this way (e.g. first 4 chars without *):

class_host,country
aaaa,country1
bbbb,country2
cccc,country3

and run something like this

my_search
| rex "//Simplified"
| eval class_host=substr(host,1,4)
| lookup csvfile.csv class_host OUTPUT country
| dedup host
| table host country

In this way lookup matches host and you can use the country field.

Bye.
Giuseppe

0 Karma

elliotproebstel
Champion

Let me see if I understand your problem. You have:
1. A csv file that maps host values to country values; and
2. Data containing values for host, which you are extracting with a rex command.

And your goal is to wind up with a table that maps host values present in #2 to their respective country values, as found from the csv file. If that's correct, it's pretty straightforward:

some search | rex extracting host value into field "host" | lookup csvfile.csv host OUTPUT country | stats values(host) AS host BY country

christoffertoft
Communicator

Hi elliot,

youre correct, sorry for my bad wording in the OP. .

I tried this, and i get results but the country table is empty.

The hostnames in the csv have the first part ( a uniquely identifying part ) of the actual hostname presented by the search. i added a star to be able to match on the first part. This should be enough right?

0 Karma

elliotproebstel
Champion

Ahh, if you are looking to implement wildcard lookup, you'll need a bit more than that.
Check out this other answer for some guidance on how to do wildcard lookups:
https://answers.splunk.com/answers/52580/can-we-use-wildcard-characters-in-a-lookup-table.html

0 Karma
Get Updates on the Splunk Community!

New in Observability - Improvements to Custom Metrics SLOs, Log Observer Connect & ...

The latest enhancements to the Splunk observability portfolio deliver improved SLO management accuracy, better ...

Improve Data Pipelines Using Splunk Data Management

  Register Now   This Tech Talk will explore the pipeline management offerings Edge Processor and Ingest ...

3-2-1 Go! How Fast Can You Debug Microservices with Observability Cloud?

Register Join this Tech Talk to learn how unique features like Service Centric Views, Tag Spotlight, and ...