fix(xsysinfo): make reported system RAM total cgroup/lxcfs-aware (#8059)
GetSystemRAMInfo derived Total from memory.TotalMemory(), which on Linux
uses syscall.Sysinfo().Totalram - the HOST kernel total. lxcfs/LXD does
NOT virtualize that value, while MemAvailable (used for Free/Available)
IS virtualized. Inside an LXD/container with a 128Gi host but a ~10Gi
container view this produced Total=128Gi, Available=10Gi => Used=118Gi,
reporting ~92% RAM usage on an idle container.
Derive Total instead from the minimum of all non-zero, non-unlimited
candidates: cgroup v2 memory.max, cgroup v1 memory.limit_in_bytes (the
kernel unlimited sentinel is ignored), /proc/meminfo MemTotal (which
lxcfs virtualizes), and the syscall.Sysinfo total as the bare-metal
fallback. On bare metal every candidate is unlimited or equals the host
total, so behavior is unchanged.
The selection/parsing lives in a pure function chooseTotalMemory(...)
taking file CONTENTS, unit-tested without a real LXD host; OS file
reads stay in a thin wrapper.
Assisted-by: claude:claude-opus-4-8 [Claude Code]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Co-authored-by: Ettore Di Giacinto <mudler@localai.io>
