Splunk Cheat Sheet

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Administration

Paths

  • All config specs:
ls /opt/splunk/etc/system/README
  • Default conf (never use)
ls /opt/splunk/etc/system/default
  • Local conf
ls /opt/splunk/etc/system/local

Splunk Configuration

server.conf

  • Allow remote login when using the free license
[general]
allowRemoteLogin = always
  • Do not show the update information
[applicationsManagement]
allowInternetAccess = false

inputs.conf

  • Set the sourcetype on the forwarder machines, this is for the universal forwarder
[monitor://path\log\file.txt*]
sourcetype = FileXYflightapi
disabled = 0

indexes.conf

  • /opt/splunk/etc/apps/search/local
[security]
coldPath = $SPLUNK_DB/security/colddb
enableDataIntegrityControl = 0
enableTsidxReduction = 0
homePath = $SPLUNK_DB/security/db
maxTotalDataSizeMB = 1024
thawedPath = $SPLUNK_DB/security/thaweddb


inputs.conf

  • Server
[splunktcp://9997]
queueSize = 2MB
disabled = 0

btool

  • Check Syntax
./splunk btool check
  • List server.conf / general
./splunk btool server list general

or server.conf / sslConfig 

./splunk btool server list sslConfig
  • See where changes come from
./splunk btool server list general --debug
  • Show the script stanza form Inputs.conf
./splunk btool inputs list script
  • and see wehre the change comes from
./splunk btool inputs list script --debug
  • Or monitor
./splunk btool inputs list monitor

Server Commands

  • Show running server.conf
./splunk show config server

/or inputs.conf 

./splunk show config inputs
  • Set/Show the server name
./splunk set servername splunk##
./splunk show servername
  • Set/Show the default host name
./splunk show default-hostname
./splunk show default-hostname
  • Add a test index to the search app
./splunk add index test -app search
  • Add a receiving port to the search app
./splunk enable listen 9997  -app search
  • Force reload
https://domain.com:8000/debug/refresh

Config Tracker (Splunk9+)

index = _configtracker
index=_configtracker server.conf serverName

Diag

  • Diag selections
   These switches select which categories of information should be
   collected.  The current components available are: index_files,
   index_listing, dispatch, etc, log, searchpeers, consensus,
   conf_replication_summary, suppression_listing, rest, kvstore,
   file_validate, profiler
  • Sample
./splunk diag --collect=index_files,etc


btool

  • List all configurations incl. the location
btool check --debug
  • List all input stanzas
splunk btool inputs list
/opt/splunk/bin/splunk btool outputs list --debug
/opt/splunk/bin/splunk btool inputs list --debug
/opt/splunk/bin/splunk btool server list --debug
/opt/splunk/bin/splunk btool props list --debug
/opt/splunk/bin/splunk btool indexes list --debug
  • Database Dir: /opt/splunk/var/lib/splunk/

Cluster

  • Cluster Status, only available from the cluster master
./bin/splunk show cluster-status 
./bin/splunk show cluster-status -auth admin:$(</mnt/splunk-secrets/password)
  • Including indexes
./bin/splunk show cluster-status --verbose
./bin/splunk list cluster-config
./bin/splunk show cluster-bundle-status


SH-Cluster

  • SH Cluster Status
bin/splunk show shcluster-status -auth admin:$(</mnt/splunk-secrets/password)
splunk show shcluster-status --verbose
bin/splunk list shcluster-member-info
  • Restart the search head cluster
splunk rolling-restart shcluster-members
  • Force App Update
splunk apply shcluster-bundle -target <URI>:<management_port> -auth <username>:<password>

Note: To obtain an URI you may use splunk show shcluster-status

KV Store

  • Status
bin/splunk show kvstore-status -auth admin:$(</mnt/splunk-secrets/password)
  • Clean
bin/splunk stop && bin/splunk clean kvstore --local -f ; bin/splunk start
  • Resync
splunk resync kvstore

Smart Store

  • Check Filesystem:
bin/splunk cmd splunkd rfs -- ls --starts-with volume:remote_store
  • Check Logs
cat var/log/splunk/splunkd.log | grep S3

Debugging Searches

General

  • Search Splunkd Log
index=_internal sourcetype=splunkd
  • Status / LogLevel
index=_internal sourcetype=splunkd status_code=*
index=_internal sourcetype=splunkd log_level=ERROR


Apps

  • ConfDeployment
index=_internal component=ConfDeployment data.task=*Apps

index=_internal sourcetype=splunkd_conf | top data.task
  • Checking SHC Bundle Deployment Status
index=_internal component=ConfDeployment data.task=*Apps
| table host data.source data.source data.target_label data.task data.status
  • Filter for SRC
index=_internal sourcetype=splunkd_conf data.task=createDeployableApps | rex "\"src\":\"(?<src>[^\"]+)\"" | top _time,src


  • Find missing baseline
index=_internal sourcetype=splunkd_conf
STOP_ON_MISSING_LOCAL_BASELINE | timechart count by host
  • Overall configuration behaviour
index=_internal sourcetype=splunkd_conf pullFrom 
data.to_repo!=*skipping* | timechart count by data.to_repo
  • Evidence of Caption Switching
index=_internal sourcetype=splunkd_conf pullFrom
data.from_repo!=*skipping* | timechart count by data.from_repo
  • Find the destructive resynch events
index=_internal sourcetype=splunkd_conf installSnapshot
| timechart count by host


  • App Creation
index=_internal sourcetype=splunkd "Detected app creation"

Mongod startup

index="_internal" MongoDB starting | top host

index="_internal" "MongoDB starting" source="/opt/splunk/var/log/splunk/mongod.log"

S3

  • SmartStore
index=_internal sourcetype=splunkd S3Client

Searching

Timechart

M=CB PCC=SYDXXX | timechart max(DTM) as CRSMessages span=30s


Sparkline

M=CB  | stats sparkline max(DTM) as Messages by PCC

Lookups

  • List Lookups by Rest
| rest /services/data/lookup-table-files

Lookups are used to normalize data, currently there are lookups defined for: 

| inputlookup name
  • Sample Lookup Query, Show the top bookings and show the carrier name
M=BOI earliest=-1d  latest=now   | stats count(AIR) as Amount by AIR | sort Amount desc, limit=20 |  lookup airlines Code as AIR OUTPUT Hint 
| rename Hint as Carrier | fields Carrier, Amount
  • Sample Lookup Query, Show the top PCCs and show the customer name
M=FAPI CMD=GetFares | top PCC showperc=f |  lookup pcc PCC as PCC OUTPUT Owner,CRSName | rename Owner as Customer | fields Customer, count

Extract Json

  • Sample
info  2023-05-12 01:14:01: MQTT publish: topic 'zigbee2mqtt/0xa4c138acf7922221', payload '{"battery":100,"illuminance":11,"keep_time":"10","linkquality":14,"occupancy":false,"sensitivity":"high"}'
  • Search
sourcetype=zigbee2mqtt zigbee2mqtt/0xa4c1381e3ed015b7
| rex field=_raw "(?<json_field>\{.*\})"
| spath input=json_field
| table _time occupancy battery tamper
  • Sort by time and output the most recent record
sourcetype=zigbee2mqtt zigbee2mqtt/0xa4c1381e3ed015b7
| rex field=_raw "(?<json_field>\{.*\})"
| spath input=json_field
| sort - _time
| head 1
| table _time occupancy battery tamper

Advanced Search Samples

Regex Samples

String to search: 

Feb 13 14:07:02 10.0.3.30 Feb 13 14:07:02 mail mimedefang.pl[10780]: MDLOG,s1DD71da017590,mail_in,,,<support@domain.com>,<support@domain.com>,Warning Message

Regex to extract the message id: 

explorer mimedefang.pl | rex field=_raw "MDLOG\,(?<MSGID>.*),mail*" | top 100 MSGID,_time | fields _time, MSGID

String to search: 

Feb 13 13:59:57 10.0.3.6 Feb 13 13:59:57 neptun vsftpd[8973]: [keytravel] FTP response: Client "194.74.154.185", "226 Transfer complete."

Regex to extract the login: 

host="10.0.3.6" ": [*]" FTP | rex field=_raw "(?<Login>\s{1}\[.*\])" | top Login

String to search: 

Mar 5 15:07:10 10.0.3.30 Mar 5 15:07:10 mail sm-mta[15042]: s25E727n015042: Milter add: header: X-Spam-Status: Yes, score=21.8 required=5.0 tests=BAYES_99,GEO_MAIL_SEARCH,\n \tHELO_DYNAMIC_IPADDR,HTML_MESSAGE,MIME_HTML_ONLY,RCVD_IN_BL_SPAMCOP_NET,\n\tRCVD_IN_BRBL_LASTEXT,RCVD_IN_PBL,RCVD_IN_PSBL,RCVD_IN_RP_RNBL, \n\tRCVD_IN_SORBS_DUL,RCVD_IN_XBL,RDNS_DYNAMIC,SPF_NEUTRAL,URIBL_DBL_SPAM,\n\tURIBL_WS_SURBL

Regex to extract the message id: 

host="10.0.3.30"  "X-Spam-Status: Yes" |  rex field=_raw "]: (?<MSGID>.*): Milter" | top MSGID

String to search: 

M=FEEDEDF OAD=142 TOTFLIGHTFILES=71 TOTALOMAFILES=71 TOTNBRFLIGHTS=4406 TOTNBRALOMAS=6066 TOTKEYS=10614 SIZETOT=8839080 DURATION=13 TTL=432000 INFO=0 Host=VM-XC01 Job=hhh_edf_NL_2018-11-19-1349-1-90-RT.csv   Code=HHH-FR-01

Regex to extract the date range (1-90): 

M=FEEDEDF | rex field=_raw "Job=hhh_edf_\w+-\d+-\d+-\d+-(?<STR>.*\d*-\d*)-RT"  |  top STR

Regex to expand date to day, month and year, sample: 

DATE=2020-01-01 ....

Regex 

rex field=DATE "(?<Year>[^\-]+)\-(?<Month>[^\-]+)\-(?<Day>[^\-]+)"

Then aggregate by 

stats sum(...) as Something  by Month Year

Sample: 

Oct 31 12:14:39 192.168.100.1 %ASA-4-106023: Deny tcp src outside:185.176.27.178/46086 dst inside:192.168.100.237/12834 by access-group "static_outside" [0x0, 0x0]

Regex: 

host="192.168.100.1" | rex field=_raw "Deny tcp src outside:(?<SRC>[^\/]+).*dst inside:(?<DST>[^\/]+)\/(?<PORT>[^\s+]+)" 
|  top SRC,DST,PORT

Sample: 

Jun  3 15:29:32 192.168.100.1 %ASA-6-302013: Built inbound TCP connection 2154199512 for outside:212.19.51.190/64499 (212.19.51.190/64499) to inside:192.168.100.240/443 (146.0.228.21/443)

Regex to get a table of SRC,DST and Port 

host="192.168.100.1" Built inbound TCP connection *  | rex field=_raw "for outside:(?<SRC>[^\/]+)" | rex field=_raw "to inside:(?<DST>[^\/]+)\/(?<PORT>[^\s+]+)" | top 500 SRC,DST,PORT

Lookahead Sample

Records(s) to look ahead and group 

Mar 5 15:34:20 10.0.3.30 Mar 5 15:34:20 spamd child[6707]: GSCORE=0 COU=ES ASN=AS12357 IP=77.230.132.146 MFROM=ibe@elegancejewelrydesigns.com MTO=ibe@hitchhiker.com  MSGID=s25EYHtn016074 HELO=static-146-132-230-77.ipcom.comunitel.net IPN=1306952850 LAT=40.0000 LON=-4.0000 CTY=0 
Mar 5 15:34:24 10.0.3.30 Mar 5 15:34:24 mail sm-mta[16074]: s25EYHtn016074: Milter add: header: X-Spam-Status: Yes, score=23.4 required=3.0 tests=BAYES_99,CK_HELO_GENERIC,\n\tGEO_MAIL_SEARCH,HELO_DYNAMIC_IPADDR,HTML_MESSAGE,MIME_HTML_ONLY,\n\tRAZOR2_CF_RANGE_51_100,RAZOR2_CF_RANGE_E8_51_100,RAZOR2_CHECK,\n\tRCVD_IN_BL_SPAMCOP_NET,RCVD_IN_BRBL_LASTEXT,RCVD_IN_PSBL,RCVD_IN_SORBS_WEB,\n\tRCVD_IN_XBL,SPF_NEUTRAL,URIBL_BLACK,URIBL_DBL_SPAM,URIBL_JP_SURBL,\n\tURIBL_WS_SURBL autolearn=spam version=3.3.1

Query: 

earliest=-1d  latest=now host="10.0.3.30"  "X-Spam-Status: Yes" OR GSCORE |  rex field=_raw "]: (?<MSGID>.*): Milter" |  transaction MSGID | search "X-Spam-Status: Yes" | top MFROM

Transaction

Transaction sample 

TIME>20  | transaction TID | rename TIME as ResponseTime | table _time,TID,host,ResponseTime,DEP,ARR,M,SC,SS,PCC | search PCC=XXX

Append two searches

  • Use appendcols
M=FAPI FT=1 STAT=0 USR=USR.PROD | stats count(CMD) as XXX | appendcols [search M=FAPI FT=1 STAT=0 USR NOT XXXX.PROD | stats count(CMD) as OTHER]

Links

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