providers/qemu: read modprobe path from distro package

Author: bgilbert

docs/release-notes.md

@@ -27,6 +27,7 @@ Starting with this release, ignition-validate binaries are signed with the
 - Correctly document Tang `advertisement` field as optional
 - Fix failure disabling nonexistent unit with systemd ≥ 252
 - Don't relabel a mount point that already exists
+- qemu: Use distro-specific `modprobe` path when loading kernel modules
 
 ### Test changes
 

internal/providers/qemu/qemu_blockdev.go

@@ -28,6 +28,7 @@ import (
 	"time"
 
 	"github.com/coreos/ignition/v2/config/v3_5_experimental/types"
+	"github.com/coreos/ignition/v2/internal/distro"
 	"github.com/coreos/ignition/v2/internal/log"
 	"github.com/coreos/ignition/v2/internal/platform"
 	"github.com/coreos/ignition/v2/internal/providers/util"
@@ -52,7 +53,7 @@ func init() {
 func fetchConfig(f *resource.Fetcher) (types.Config, report.Report, error) {
 	f.Logger.Warning("Fetching the Ignition config via the Virtio block driver is currently experimental and subject to change.")
 
-	_, err := f.Logger.LogCmd(exec.Command("modprobe", "virtio_blk"), "loading Virtio block driver module")
+	_, err := f.Logger.LogCmd(exec.Command(distro.ModprobeCmd(), "virtio_blk"), "loading Virtio block driver module")
 	if err != nil {
 		return types.Config{}, report.Report{}, err
 	}

internal/providers/qemu/qemu_fwcfg.go

@@ -30,6 +30,7 @@ import (
 	"time"
 
 	"github.com/coreos/ignition/v2/config/v3_5_experimental/types"
+	"github.com/coreos/ignition/v2/internal/distro"
 	"github.com/coreos/ignition/v2/internal/platform"
 	"github.com/coreos/ignition/v2/internal/providers/util"
 	"github.com/coreos/ignition/v2/internal/resource"
@@ -51,7 +52,7 @@ func init() {
 
 func fetchConfig(f *resource.Fetcher) (types.Config, report.Report, error) {
 	// load qemu_fw_cfg module
-	_, err := f.Logger.LogCmd(exec.Command("modprobe", "qemu_fw_cfg"), "loading QEMU firmware config module")
+	_, err := f.Logger.LogCmd(exec.Command(distro.ModprobeCmd(), "qemu_fw_cfg"), "loading QEMU firmware config module")
 	if err != nil {
 		return types.Config{}, report.Report{}, err
 	}