boot-service.log is never rotated and grows without limit #24755

What happened

When T3 runs as a boot service (systemd on Linux, launchd on macOS), userdata/logs/boot-service.log only ever grows. Neither manager rotates a file it appends to, and nothing in T3 trims it. A fork author reported it reaching 106 MB after offline spells (relay DNS and GitHub lookups failing and logging stack traces). On a Linux machine running a nightly it is 9.2 MB and still growing.

Diagnosis

The unit appends the service's stdout and stderr to this file (StandardOutput=append: and StandardError=append: in the systemd unit; StandardOutPath and StandardErrorPath in the launchd plist, see renderBootServiceUnit and renderBootServicePlist in apps/server/src/cloud/bootService.ts). The manager keeps that file open, so the rename-based rotation used for T3's other logs would leave the manager writing to the renamed file. I found no code that limits this file's size.

Steps to reproduce

Not deterministic: the size depends on how much the service logs. Install the boot service (t3 service install), let it run, and watch ls -l <T3 home>/userdata/logs/boot-service.log. It grows during any period where the server logs repeatedly, such as being offline.

Version

0.1.3-nightly.20261024.3630

Environment

Ubuntu 26.04, Linux 7.2.12 (x86_64), systemd 259. The macOS 106 MB figure is the fork author's report, not measured here.

Evidence

-rw-rw-r-- 1 user user 9242562 Oct 24 22:47 <T3 home>/userdata/logs/boot-service.log

Related issues

None found for this file. Searched open and closed issues and pull requests for "boot-service.log", "log rotation" and "service log grows". Open issues about T3 Connect connector logs (#16331, #24485) concern a different log.

Fix applied or workaround

None applied. I can open a pull request for this once triage confirms the direction. The branch exists: https://github.com/bompus/t3code/tree/fix/boot-service-log-cap . The unit now tells the service launcher which file the manager writes, and the launcher copies it to boot-service.log.1 and empties the live file in place past 16 MiB, at start and every 10 minutes. I ran it against a real systemd user unit appending to a file; the unit kept writing with no holes. Not tried on launchd.

Filed by

Claude Sonnet 5.5 (Claude Code in T3 Code)