cpu-template

CPU template

Size process arguments from the number of CPUs gopherd detects, so the same config adapts to whatever host or container it runs in.

Config

# CPU-aware templates: size args from detected CPUs (system + cgroup).
processes:
  - name: app
    command: /usr/local/bin/app
    args: ["--workers", "{{cpu 50%}}", "--max", "{{cpu}}"]
    on-failure: shutdown

• {{cpu}} — bare form expands to the detected CPU count.
• {{cpu 50%}} — percentage form expands to that fraction of the count (rounded).
• Detection prefers cgroup limits over the system count: cgroup v2 cpu.max CFS quota, v1 cpu.cfs_quota_us/cpu.cfs_period_us, and cpuset are honored, falling back to the host CPU count.
• CPU templates expand at service start (in args and environment), not at config load, so the value reflects the runtime environment.

Expected behavior

• On a 4-CPU host with no cgroup limit, app starts with --workers 2 --max 4.
• Under a cgroup CFS quota of 2 CPUs, it starts with --workers 1 --max 2.
• The config is portable: no hardcoded core counts.

Test

ValidateParse level — behavior is environment-dependent (cgroup limits / remote syslog / file rotation thresholds), so the test asserts the config loads and validates.

go test ./documentation/cpu-template/ -v