fix(inputs.diskio): Honor host path environment variables on Linux by WZH8898 · Pull Request #18682 · influxdata/telegraf

WZH8898 · 2026-04-09T09:17:04Z

Summary

This PR updates inputs.diskio on Linux to honor host path environment variables instead of relying on hard-coded /dev, /run, and /sys paths, addressing issue #18671.

Added support for resolving host paths with the following fallback order:

HOST_DEV / HOST_RUN / HOST_SYS
HOST_ROOT
HOST_MOUNT_PREFIX
default /dev, /run, /sys

This PR also fixes the infoCache writeback to store sysBlockPath correctly, updates the /dev fallback in resolveName() to use the resolved host device path, and updates getDeviceWWID() to read from the resolved host sysfs path.

Tests added in this PR cover:

HOST_DEV + HOST_RUN
HOST_ROOT fallback
HOST_MOUNT_PREFIX fallback
HOST_SYS handling for WWID lookup

Checklist

No AI generated code was used in this PR
AI generated code used in this PR follows the InfluxData Policy on AI-Generated Code Contributions

Related issues

resolves #18671

srebhan

Thanks for your contribution @WZH8898! Please find my comments below.

Please also adhere to our PR title schema which starts with the semantic-commit prefix and then has an uppercase verb as a first word after the colon!

srebhan

Thanks @WZH8898! Some more comments from my side.

WZH8898 · 2026-04-14T08:45:11Z

Thanks for the detailed review, I updated the patch accordingly:

DEVPATH handling was simplified to only strip sysPath (removed the extra "/sys" trim and leading-slash normalization).
In resolveName(), I removed the /dev/absolute-path trimming logic and now only do the fallback resolution relative to d.devPath.
Tests now consistently initialize the plugin via require.NoError(t, plugin.Init()) (using a small helper), instead of manually setting devPath/runPath/sysPath.
I replaced the t.TempDir() host-path setup with fixed testdata/hostfs fixtures, as suggested. Added:
testdata/hostfs/dev/mockdev
testdata/hostfs/sys/block/sda/wwid

This keeps the test inputs explicit/reproducible and aligns with your requested style.

srebhan

Thanks @WZH8898! Just one more comment...

srebhan

Thanks @WZH8898! Some more comments regarding the tests.

WZH8898 · 2026-04-21T07:45:14Z

Thanks @WZH8898! Some more comments regarding the tests.

Thanks @srebhan , addressed. I replaced setupEnv callbacks with env map[string]string and apply them in the test loop via t.Setenv, removed the redundant createDev indirection by joining paths at the caller side, and dropped the unix.Stat/mtime-dependent setup in favor of direct fixture-based assertions.

srebhan

Thanks @WZH8898! Just a last suggestion to improve readability...

srebhan · 2026-04-22T11:42:54Z

+	hostRoot := filepath.Join("testdata", "hostfs")
+	t.Setenv("HOST_DEV", filepath.Join(hostRoot, "dev"))


I think this is easier to read the actual path

Suggested change

hostRoot := filepath.Join("testdata", "hostfs")

t.Setenv("HOST_DEV", filepath.Join(hostRoot, "dev"))

t.Setenv("HOST_DEV", filepath.Join("testdata", "hostfs", "dev"))

srebhan · 2026-04-22T11:44:28Z

+	hostSys := filepath.Join("testdata", "hostfs", "sys")
+	t.Setenv("HOST_SYS", hostSys)


Suggested change

hostSys := filepath.Join("testdata", "hostfs", "sys")

t.Setenv("HOST_SYS", hostSys)

t.Setenv("HOST_SYS", filepath.Join("testdata", "hostfs", "sys"))

WZH8898 · 2026-04-23T09:06:07Z

Thanks @WZH8898! Just a last suggestion to improve readability...

Thanks @srebhan, addressed.

srebhan

Thanks @WZH8898! Just one more small improvement...

telegraf-tiger · 2026-04-28T08:10:11Z

Download PR build artifacts for linux_amd64.tar.gz, darwin_arm64.tar.gz, and windows_amd64.zip.
Downloads for additional architectures and packages are available below.

☺️ This pull request doesn't significantly change the Telegraf binary size (less than 1%)

📦 Click here to get additional PR build artifacts

Artifact URLs

. DEB	. RPM	. TAR . GZ	. ZIP
amd64.deb	aarch64.rpm	darwin_amd64.tar.gz	windows_amd64.zip
arm64.deb	armel.rpm	darwin_arm64.tar.gz	windows_arm64.zip
armel.deb	armv6hl.rpm	freebsd_amd64.tar.gz	windows_i386.zip
armhf.deb	i386.rpm	freebsd_armv7.tar.gz
i386.deb	ppc64le.rpm	freebsd_i386.tar.gz
mips.deb	riscv64.rpm	linux_amd64.tar.gz
mipsel.deb	s390x.rpm	linux_arm64.tar.gz
ppc64el.deb	x86_64.rpm	linux_armel.tar.gz
riscv64.deb		linux_armhf.tar.gz
s390x.deb		linux_i386.tar.gz
		linux_mips.tar.gz
		linux_mipsel.tar.gz
		linux_ppc64le.tar.gz
		linux_riscv64.tar.gz
		linux_s390x.tar.gz

WZH8898 · 2026-04-28T08:22:01Z

Thanks @WZH8898! Just one more small improvement...

Thanks @srebhan, addressed.

srebhan

Perfect. Thanks @WZH8898!

skartikey

@WZH8898 Thanks for the contribution!

telegraf-tiger Bot added fix pr to fix corresponding bug plugin/input 1. Request for new input plugins 2. Issues/PRs that are related to input plugins labels Apr 9, 2026

WZH8898 force-pushed the fix-diskio-host-paths branch from c9ebb0e to cad1114 Compare April 9, 2026 09:47

srebhan reviewed Apr 9, 2026

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Comment thread plugins/inputs/diskio/diskio_linux.go Outdated

Comment thread plugins/inputs/diskio/diskio_linux.go Outdated

srebhan self-assigned this Apr 9, 2026

WZH8898 changed the title ~~fix(inputs.diskio): honor host path environment variables on linux~~ fix(inputs.diskio): Honor host path environment variables on Linux Apr 10, 2026

WZH8898 force-pushed the fix-diskio-host-paths branch from cad1114 to 88fcfbc Compare April 10, 2026 08:17

srebhan reviewed Apr 13, 2026

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WZH8898 force-pushed the fix-diskio-host-paths branch from 517fda1 to 3c65601 Compare April 14, 2026 08:18

srebhan reviewed Apr 16, 2026

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Comment thread plugins/inputs/diskio/diskio_linux_test.go Outdated

WZH8898 force-pushed the fix-diskio-host-paths branch from 3c65601 to e8da02b Compare April 17, 2026 07:56

srebhan mentioned this pull request Apr 17, 2026

inputs/diskio: honour HOST_MOUNT_PREFIX / HOST_DEV #18732

Closed

srebhan reviewed Apr 17, 2026

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Comment thread plugins/inputs/diskio/diskio_linux_test.go Outdated

Comment thread plugins/inputs/diskio/diskio_linux_test.go Outdated

Comment thread plugins/inputs/diskio/diskio_linux_test.go Outdated

WZH8898 force-pushed the fix-diskio-host-paths branch from e8da02b to f15edce Compare April 21, 2026 07:20

srebhan reviewed Apr 22, 2026

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WZH8898 force-pushed the fix-diskio-host-paths branch 2 times, most recently from e11389a to c2b173c Compare April 23, 2026 06:59

srebhan reviewed Apr 27, 2026

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Comment thread plugins/inputs/diskio/diskio_linux_test.go Outdated

fix(inputs.diskio): honor host path environment variables on linux

ed21ecf

WZH8898 force-pushed the fix-diskio-host-paths branch from c2b173c to ed21ecf Compare April 28, 2026 07:50

srebhan approved these changes Apr 28, 2026

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srebhan added the ready for final review This pull request has been reviewed and/or tested by multiple users and is ready for a final review. label Apr 28, 2026

srebhan assigned skartikey and unassigned srebhan Apr 28, 2026

skartikey approved these changes Apr 28, 2026

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skartikey merged commit d2e3a60 into influxdata:master Apr 28, 2026
27 checks passed

github-actions Bot added this to the v1.38.4 milestone Apr 28, 2026

		hostRoot := filepath.Join("testdata", "hostfs")
		t.Setenv("HOST_DEV", filepath.Join(hostRoot, "dev"))

	hostRoot := filepath.Join("testdata", "hostfs")
	t.Setenv("HOST_DEV", filepath.Join(hostRoot, "dev"))
	t.Setenv("HOST_DEV", filepath.Join("testdata", "hostfs", "dev"))

		hostSys := filepath.Join("testdata", "hostfs", "sys")
		t.Setenv("HOST_SYS", hostSys)

	hostSys := filepath.Join("testdata", "hostfs", "sys")
	t.Setenv("HOST_SYS", hostSys)
	t.Setenv("HOST_SYS", filepath.Join("testdata", "hostfs", "sys"))

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WZH8898 commented Apr 9, 2026 • edited by srebhan Loading Uh oh! There was an error while loading. Please reload this page.

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WZH8898 commented Apr 14, 2026

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WZH8898 commented Apr 9, 2026 •

edited by srebhan

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WZH8898 commented Apr 21, 2026 •

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