refactor: move kernel functions to submodule

kernel/kernel_linux.go

@@ -0,0 +1,98 @@
+// Copyright 2023 Mikhail Klementev. All rights reserved.
+// Use of this source code is governed by a AGPLv3 license
+// (or later) that can be found in the LICENSE file.
+
+//go:build linux
+// +build linux
+
+package kernel
+
+import (
+	"io/ioutil"
+	"os/exec"
+	"strings"
+
+	"github.com/rs/zerolog/log"
+	"github.com/zcalusic/sysinfo"
+
+	"code.dumpstack.io/tools/out-of-tree/config"
+	"code.dumpstack.io/tools/out-of-tree/container"
+	"code.dumpstack.io/tools/out-of-tree/fs"
+)
+
+func genHostKernels(download bool) (kcfg config.KernelConfig, err error) {
+	si := sysinfo.SysInfo{}
+	si.GetSysInfo()
+
+	distroType, err := config.NewDistroType(si.OS.Vendor)
+	if err != nil {
+		return
+	}
+
+	cmd := exec.Command("ls", "/lib/modules")
+	log.Debug().Msgf("%v", cmd)
+
+	rawOutput, err := cmd.CombinedOutput()
+	if err != nil {
+		log.Print(string(rawOutput), err)
+		return
+	}
+
+	kernelsBase := "/boot/"
+	bootfiles, err := ioutil.ReadDir(kernelsBase)
+	if err != nil {
+		return
+	}
+
+	// only for compatibility, docker is not really used
+	dii := container.Image{
+		Name: config.KernelMask{
+			DistroType:    distroType,
+			DistroRelease: si.OS.Version,
+		}.DockerName(),
+	}
+
+	rootfs, err := GenRootfsImage(dii, download)
+	if err != nil {
+		return
+	}
+
+	for _, krel := range strings.Fields(string(rawOutput)) {
+		log.Debug().Msgf("generate config entry for %s", krel)
+
+		var kernelFile, initrdFile string
+		kernelFile, err = findKernelFile(bootfiles, krel)
+		if err != nil {
+			log.Warn().Msgf("cannot find kernel %s", krel)
+			continue
+		}
+
+		initrdFile, err = findInitrdFile(bootfiles, krel)
+		if err != nil {
+			log.Warn().Msgf("cannot find initrd %s", krel)
+			continue
+		}
+
+		ki := config.KernelInfo{
+			DistroType:    distroType,
+			DistroRelease: si.OS.Version,
+			KernelRelease: krel,
+
+			KernelSource: "/lib/modules/" + krel + "/build",
+
+			KernelPath: kernelsBase + kernelFile,
+			InitrdPath: kernelsBase + initrdFile,
+			RootFS:     rootfs,
+		}
+
+		vmlinux := "/usr/lib/debug/boot/vmlinux-" + krel
+		log.Print("vmlinux", vmlinux)
+		if fs.PathExists(vmlinux) {
+			ki.VmlinuxPath = vmlinux
+		}
+
+		kcfg.Kernels = append(kcfg.Kernels, ki)
+	}
+
+	return
+}