Extract host memory derivation into calculateHostMemoryUsage and use
saturating subtraction to prevent uint64 underflow caused by race
conditions when reading /proc/meminfo. Also ensure UsedPercent guards
against division by zero.
Co-authored-by: Sven van Ginkel <svenvanginkel@icloud.com>
decode() reused a single json.Decoder across responses. Once a decode errored on a truncated or malformed body (e.g. a container removed mid-request), the decoder stayed desynced and every subsequent decode failed, silently stopping all container stats until the agent was restarted. Decode the buffered bytes with json.Unmarshal instead, which keeps the reusable read buffer but holds no cross-call state.
Regression from d67d638.
Some enterprise NVMe drives (e.g. Dell Ent NVMe CM7 U.2) report capacity
via nvme_total_capacity instead of user_capacity.bytes in smartctl output.
The NVMe SMART parser now falls back to nvme_total_capacity when
user_capacity.bytes is zero.
- move hub's GetEnv function to new utils package to more easily share
across different hub packages
- change System.HasUser to take core.Record instead of user ID string
- add tests
Previously, the agent shared a single PrevReadTime timestamp across all
collection intervals (e.g., 1s and 60s). This caused the 60s collector
to divide its accumulated 60s byte delta by the tiny time elapsed since
the last 1s collection, resulting in astronomically inflated network
rates. The fix introduces per-cache-time read time tracking, ensuring
calculations for each interval use their own independent timing context.
- Match FILESYSTEM directly against I/O devices if partition lookup
fails
- Fall back to the most active I/O device if no root device is detected
- Add WARN logs in final fallback case to most active device
findIoDevice now normalizes device names and falls back to prefix-based
matching when partition names differ from IOCounter names (e.g. nda0p2 →
nda0 on FreeBSD). The most-active prefix-related device is selected,
avoiding the broad "most active of all" heuristic that caused Docker
misattribution in #1737.
