Replace vmstat gem with /proc reads - #5332
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The vmstat gem is a native C extension with no Windows support (its build fails there), and it surfaced in an outdated-dependency audit. On the Linux ccng runtime all three values it provided are available directly from /proc, so the gem can be dropped from lib/vcap/stats.rb. Behaviour is preserved. vmstat's Linux backend reads /proc/meminfo, so: - memory_free_bytes = (Inactive + MemFree) * 1024 - memory_used_bytes = (MemTotal - Inactive - MemFree) * 1024 (equals vmstat's active+wired by conservation - the buckets sum to MemTotal) - cpu_load_average = first field of /proc/loadavg Verified against the live vmstat gem on a production CF API VM: 0.0% diff on both memory metrics, load average identical to rounding. Non-Linux dev machines (Mac/Windows) return 0, where these metrics have no consumer. Add a stats spec covering all three methods on both the Linux and non-Linux paths, which previously had no direct coverage.
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The vmstat gem is a native C extension with no Windows support (its build fails there), and it surfaced in an outdated-dependency audit. On the Linux ccng runtime all three values it provided are available directly from /proc, so the gem can be dropped from lib/vcap/stats.rb.
Behaviour is preserved. vmstat's Linux backend reads /proc/meminfo, so:
Verified against the live vmstat gem on a production CF API VM: 0.0% diff on both memory metrics, load average identical to rounding. Non-Linux dev machines (Mac/Windows) return 0, where these metrics have no consumer.
Add a stats spec covering all three methods on both the Linux and non-Linux paths, which previously had no direct coverage.
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mainbranchI have run all the unit tests using
bundle exec rakeI have run CF Acceptance Tests