Update readme docker example #3215
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Signed-off-by: czephyr <[email protected]>
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| quay.io/prometheus/node-exporter:latest \ | ||
| --path.rootfs=/host | ||
| --path.rootfs=/host --path.udev.data=/host/run/udev/data --path.procfs=/host/proc --path.sysfs=/host/sys |
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This shouldn't need to be changed.
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Does --path.rootfs=/host imply all the following flags?
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The udev flag is not obvious and diskstats is enabled by default. If its not set it runs into the warning
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Hmm, that sounds like a bug. The --path.rootfs flag is supposed to adjust all path defaults so only the one flag is needed.
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The --path.rootfs flag is supposed to adjust all path defaults so only the one flag is needed.
Would you mind pointing out an instance of that happening in the code for /proc or /sys?
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For example, the os_release.go uses rootfsPath to build the path.
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Ah for /proc and /sys there is no explicitness in the code because of this I think #912 (comment)
So its possible that when udev flag has been added the --path.rootfs behavior wasn't taken in consideration. I'll attempt a PR if I find it.
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Correct, but those two paths (/proc and /sys) don't need redirect by default because the node_exporter is executed in the host PID namespace in order to access host metrics.
IIRC, we used to have examples of adjusting --path.procfs with a volume mount. But it turned out we still needed host PID anyway. So those recommendations were dropped. Now we only need to use --path.rootfs.
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Either the udev flag is better documented and explained or #3216
Co-authored-by: Ben Kochie <[email protected]> Signed-off-by: Alfedo Funicello <[email protected]>
A suggestion to update the docker example to be a little more explanatory on the flags and mounts