Add initramfs stage to warewulfd

The initramfs stage supports serving an initramfs image from within the
container image, typically generated by dracut.

Signed-off-by: xu yang <xyang@ciq.com>
Signed-off-by: Jonathon Anderson <janderson@ciq.com>

CHANGELOG.md

@@ -38,6 +38,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Added
 
 - Add examples for building overlays in parallel to documentation
+- Add `stage=initramfs` to warewulfd provision to serve initramfs from container image. #1115
 
 ### Changed
 

internal/pkg/container/config.go

@@ -1,11 +1,25 @@
 package container
 
 import (
+	"fmt"
 	"path"
 
+	"github.com/warewulf/warewulf/internal/pkg/util"
+	"github.com/warewulf/warewulf/internal/pkg/wwlog"
+
 	warewulfconf "github.com/warewulf/warewulf/internal/pkg/config"
 )
 
+var (
+	initramfsSearchPaths = []string{
+		// This is a printf format where the %s will be the kernel version
+		"boot/initramfs-%s",
+		"boot/initramfs-%s.img",
+		"boot/initrd-%s",
+		"boot/initrd-%s.img",
+	}
+)
+
 func SourceParentDir() string {
 	conf := warewulfconf.Get()
 	return conf.Paths.WWChrootdir
@@ -27,3 +41,16 @@ func ImageParentDir() string {
 func ImageFile(name string) string {
 	return path.Join(ImageParentDir(), name+".img")
 }
+
+// InitramfsBootPath returns the dracut built initramfs path, as dracut built initramfs inside container
+// the function returns host path of the built file
+func InitramfsBootPath(image, kver string) (string, error) {
+	for _, searchPath := range initramfsSearchPaths {
+		initramfs_path := path.Join(RootFsDir(image), fmt.Sprintf(searchPath, kver))
+		wwlog.Debug("Looking for initramfs at: %s", initramfs_path)
+		if util.IsFile(initramfs_path) {
+			return initramfs_path, nil
+		}
+	}
+	return "", fmt.Errorf("Failed to find a target kernel version initramfs")
+}

internal/pkg/container/config_test.go

@@ -0,0 +1,88 @@
+package container
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	warewulfconf "github.com/warewulf/warewulf/internal/pkg/config"
+)
+
+func TestInitramfsBootPath(t *testing.T) {
+	conf := warewulfconf.Get()
+	temp, err := os.MkdirTemp(os.TempDir(), "ww-conf-*")
+	assert.NoError(t, err)
+	defer os.RemoveAll(temp)
+	conf.Paths.WWChrootdir = temp
+
+	assert.NoError(t, os.MkdirAll(filepath.Join(RootFsDir("image"), "boot"), 0700))
+
+	tests := []struct {
+		name      string
+		initramfs []string
+		ver       string
+		err       error
+		retName   string
+	}{
+		{
+			name:      "ok case 1",
+			initramfs: []string{"initramfs-1.1.1.aarch64.img"},
+			ver:       "1.1.1.aarch64",
+			err:       nil,
+		},
+		{
+			name:      "ok case 2",
+			initramfs: []string{"initrd-1.1.1.aarch64"},
+			ver:       "1.1.1.aarch64",
+			err:       nil,
+		},
+		{
+			name:      "ok case 3",
+			initramfs: []string{"initramfs-1.1.1.aarch64"},
+			ver:       "1.1.1.aarch64",
+			err:       nil,
+		},
+		{
+			name:      "ok case 4",
+			initramfs: []string{"initrd-1.1.1.aarch64.img"},
+			ver:       "1.1.1.aarch64",
+			err:       nil,
+		},
+		{
+			name:      "error case, wrong init name",
+			initramfs: []string{"initrr-1.1.1.aarch64.img"},
+			ver:       "1.1.1.aarch64",
+			err:       fmt.Errorf("Failed to find a target kernel version initramfs"),
+		},
+		{
+			name:      "error case, wrong ver",
+			initramfs: []string{"initrr-1.1.1.aarch64.img"},
+			ver:       "1.1.2.aarch64",
+			err:       fmt.Errorf("Failed to find a target kernel version initramfs"),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Logf("running test: %s", tt.name)
+		for _, init := range tt.initramfs {
+			assert.NoError(t, os.WriteFile(filepath.Join(RootFsDir("image"), "boot", init), []byte(""), 0600))
+		}
+		initPath, err := InitramfsBootPath("image", tt.ver)
+		assert.Equal(t, tt.err, err)
+		if err == nil {
+			assert.NotEmpty(t, initPath)
+		} else {
+			assert.Empty(t, initPath)
+		}
+
+		if tt.retName != "" {
+			assert.Equal(t, filepath.Base(initPath), tt.retName)
+		}
+		// remove the file
+		for _, init := range tt.initramfs {
+			assert.NoError(t, os.Remove(filepath.Join(RootFsDir("image"), "boot", init)))
+		}
+	}
+}

internal/pkg/warewulfd/parser.go

@@ -73,6 +73,8 @@ func parseReq(req *http.Request) (parserInfo, error) {
 			ret.stage = "runtime"
 		} else if stage == "efiboot" {
 			ret.stage = "efiboot"
+		} else if stage == "initramfs" {
+			ret.stage = "initramfs"
 		}
 	}
 

internal/pkg/warewulfd/provision.go

@@ -56,12 +56,13 @@ func ProvisionSend(w http.ResponseWriter, req *http.Request) {
 	}
 
 	status_stages := map[string]string{
-		"efiboot": "EFI",
-		"ipxe":    "IPXE",
-		"kernel":  "KERNEL",
-		"kmods":   "KMODS_OVERLAY",
-		"system":  "SYSTEM_OVERLAY",
-		"runtime": "RUNTIME_OVERLAY"}
+		"efiboot":   "EFI",
+		"ipxe":      "IPXE",
+		"kernel":    "KERNEL",
+		"kmods":     "KMODS_OVERLAY",
+		"system":    "SYSTEM_OVERLAY",
+		"runtime":   "RUNTIME_OVERLAY",
+		"initramfs": "INITRAMFS"}
 
 	status_stage := status_stages[rinfo.stage]
 	var stage_file string
@@ -213,6 +214,19 @@ func ProvisionSend(w http.ResponseWriter, req *http.Request) {
 		} else {
 			wwlog.Warn("No conainer set for node %s", node.Id.Get())
 		}
+	} else if rinfo.stage == "initramfs" {
+		if node.ContainerName.Defined() {
+			_, kver, err := kernel.FindKernel(container.RootFsDir(node.ContainerName.Get()))
+			if err != nil {
+				wwlog.Error("No kernel found for initramfs for container %s: %s", node.ContainerName.Get(), err)
+			}
+			stage_file, err = container.InitramfsBootPath(node.ContainerName.Get(), kver)
+			if err != nil {
+				wwlog.Error("No initramfs found for container %s: %s", node.ContainerName.Get(), err)
+			}
+		} else {
+			wwlog.Warn("No container set for node %s", node.Id.Get())
+		}
 	}
 
 	wwlog.Serv("stage_file '%s'", stage_file)

internal/pkg/warewulfd/provision_test.go

@@ -30,6 +30,7 @@ var provisionSendTests = []struct {
 	{"find shim", "/efiboot/shim.efi", "", 404, "10.10.10.11:9873"},
 	{"find grub", "/efiboot/grub.efi", "", 200, "10.10.10.10:9873"},
 	{"find grub", "/efiboot/grub.efi", "", 404, "10.10.10.11:9873"},
+	{"find initramfs", "/provision/00:00:00:ff:ff:ff?stage=initramfs", "", 200, "10.10.10.10:9873"},
 }
 
 func Test_ProvisionSend(t *testing.T) {
@@ -84,6 +85,11 @@ nodes:
 		_, err := os.Create(path.Join(containerDir, "suse/rootfs/usr/share/efi/x86_64/", "grub.efi"))
 		assert.NoError(t, err)
 	}
+	assert.NoError(t, os.MkdirAll(path.Join(containerDir, "suse/rootfs/boot"), 0700))
+	{
+		_, err := os.Create(path.Join(containerDir, "suse/rootfs/boot", "initramfs-.img"))
+		assert.NoError(t, err)
+	}
 
 	dbErr := LoadNodeDB()
 	assert.NoError(t, dbErr)