Test logs (loggen)

loggen (in cmd/loggen) sends random, realistic test logs at a steady rate, for trying SIEMLite out or load-testing it. It describes a small company: a firewall, two web servers, an SSH bastion, VPN, DNS, a database, mail, backups and workstation antivirus, with attacks mixed in (SSH brute force, port scans, malware calling home and password spraying against the VPN), so the alert rules have something to find.

loggen -eps 10                       # to SIEMLite on this machine
loggen -eps 1k -for 10m              # a load test
loggen -eps 100 -to udp://siem:514   # to any SIEM over syslog
loggen -eps 1 -to stdout             # just look at the lines

• Rate: -eps takes 1, 10, 100, 1k, 10k, 100k or 1m events a second (any number works). It keeps that rate for as long as it runs (until you stop it, or -for ends it): a slow moment or a restart of the receiver is made up for, but only up to a second's worth, so a long outage doesn't end in a flood. It can make well over a million lines a second; how many arrive depends on the receiver. When SIEMLite is busy it answers 503, and loggen waits as asked and sends the rest again, so nothing is lost, and the progress line says when the rate it achieved is below the one you asked for.
• Keep it running in the background: docker compose exec stops when your terminal does. To send continuously, turn on the loggen service: add testlogs to COMPOSE_PROFILES in .env (COMPOSE_PROFILES=testlogs, or ai,testlogs), set the rate with LOGGEN_EPS=100 (default 10), and run docker compose up -d. It restarts with Docker, carries on through restarts and upgrades of SIEMLite, and logs a progress line a minute. Remove testlogs and run docker compose up -d --remove-orphans to stop it. Without Docker, run nohup loggen -eps 10 > /dev/null 2>&1 &, or from systemd or any process manager.
• Set up for you: on first start SIEMLite creates a Log generator parser and an access token source that uses it, and saves the token as siemlite-loggen.token next to the database. loggen reads that file and trusts siemlite.crt, looking in the current folder and in /data, so it needs no options on the same machine. With Docker it's in the image: docker compose exec siemlite loggen -eps 10. The token can only send logs. To turn it off, choose Manage on its row on the Sources page, then Disable. While it's disabled loggen keeps retrying and carries on by itself once you choose Enable. Delete removes its token for good; then create a new access token with the Log generator parser and give it to loggen with -token or LOGGEN_TOKEN. The source isn't created again.
• Its own format, not syslog, JSON or key=value, so it shows a parser at work: time|host|app|level|action|src_ip|src_port|dst_ip|dst_port|user|message, for example 2026-10-04T13:42:07.123Z|bastion-01|sshd|warning|auth.failure|203.0.113.7|51234|10.0.4.12|22|root|Failed password for root from 203.0.113.7. Empty fields are -. Addresses outside the company are from documentation ranges only.
• For other SIEMs: point -to at a syslog port (UDP or TCP, RFC 3164), or at any URL that takes lines like SIEMLite's /api/v1/logs (-servername checks its certificate against another name, -insecure skips the check). It uses only Go's standard library, and -seed repeats the same logs.

Binaries for loggen come with every release, next to siemlite. To build it: go build -o loggen ./cmd/loggen.