cli: add hypervisor initrd config option

Add `initrd=[path]` option to configuration.toml and use it to set
the HypervisorConfig.InitrdPath option.

The default value of hypervisor image option is removed since we want
to allow it to be unset. For the same reason, there is no default value
for hypervisor initrd option either.

Signed-off-by: Peng Tao <bergwolf@gmail.com>

Makefile

@@ -37,6 +37,7 @@ PROJECT_BUG_URL = $(PROJECT_URL)/kata-containers/issues/new
 BIN_PREFIX = $(PROJECT_TYPE)
 PROJECT_DIR = $(PROJECT_TAG)
 IMAGENAME = $(PROJECT_TAG).img
+INITRDNAME = $(PROJECT_TAG)-initrd.img
 
 TARGET = $(BIN_PREFIX)-runtime
 TARGET_OUTPUT = $(CURDIR)/$(TARGET)
@@ -77,6 +78,7 @@ PKGRUNDIR := $(LOCALSTATEDIR)/run/$(PROJECT_DIR)
 PKGLIBEXECDIR := $(LIBEXECDIR)/$(PROJECT_DIR)
 
 KERNELPATH := $(PKGDATADIR)/vmlinuz.container
+INITRDPATH := $(PKGDATADIR)/$(INITRDNAME)
 IMAGEPATH := $(PKGDATADIR)/$(IMAGENAME)
 FIRMWAREPATH :=
 
@@ -140,6 +142,8 @@ USER_VARS += DESTSYSCONFIG
 USER_VARS += DESTTARGET
 USER_VARS += IMAGENAME
 USER_VARS += IMAGEPATH
+USER_VARS += INITRDNAME
+USER_VARS += INITRDPATH
 USER_VARS += MACHINETYPE
 USER_VARS += KERNELPATH
 USER_VARS += FIRMWAREPATH
@@ -244,6 +248,7 @@ var showConfigPathsOption = fmt.Sprintf("%s-show-default-config-paths", projectP
 var defaultHypervisorPath = "$(QEMUPATH)"
 var defaultImagePath = "$(IMAGEPATH)"
 var defaultKernelPath = "$(KERNELPATH)"
+var defaultInitrdPath = "$(INITRDPATH)"
 var defaultFirmwarePath = "$(FIRMWAREPATH)"
 var defaultMachineAccelerators = "$(MACHINEACCELERATORS)"
 var defaultShimPath = "$(SHIMPATH)"
@@ -319,6 +324,7 @@ $(GENERATED_FILES): %: %.in Makefile VERSION
 		-e "s|@DESTSYSCONFIG@|$(DESTSYSCONFIG)|g" \
 		-e "s|@IMAGEPATH@|$(IMAGEPATH)|g" \
 		-e "s|@KERNELPATH@|$(KERNELPATH)|g" \
+		-e "s|@INITRDPATH@|$(INITRDPATH)|g" \
 		-e "s|@FIRMWAREPATH@|$(FIRMWAREPATH)|g" \
 		-e "s|@MACHINEACCELERATORS@|$(MACHINEACCELERATORS)|g" \
 		-e "s|@KERNELPARAMS@|$(KERNELPARAMS)|g" \

cli/config.go

@@ -76,6 +76,7 @@ type tomlConfig struct {
 type hypervisor struct {
 	Path                  string `toml:"path"`
 	Kernel                string `toml:"kernel"`
+	Initrd                string `toml:"initrd"`
 	Image                 string `toml:"image"`
 	Firmware              string `toml:"firmware"`
 	MachineAccelerators   string `toml:"machine_accelerators"`
@@ -131,11 +132,21 @@ func (h hypervisor) kernel() (string, error) {
 	return resolvePath(p)
 }
 
+func (h hypervisor) initrd() (string, error) {
+	p := h.Initrd
+
+	if p == "" {
+		return "", nil
+	}
+
+	return resolvePath(p)
+}
+
 func (h hypervisor) image() (string, error) {
 	p := h.Image
 
 	if p == "" {
-		p = defaultImagePath
+		return "", nil
 	}
 
 	return resolvePath(p)
@@ -267,6 +278,11 @@ func newQemuHypervisorConfig(h hypervisor) (vc.HypervisorConfig, error) {
 		return vc.HypervisorConfig{}, err
 	}
 
+	initrd, err := h.initrd()
+	if err != nil {
+		return vc.HypervisorConfig{}, err
+	}
+
 	image, err := h.image()
 	if err != nil {
 		return vc.HypervisorConfig{}, err
@@ -289,6 +305,7 @@ func newQemuHypervisorConfig(h hypervisor) (vc.HypervisorConfig, error) {
 	return vc.HypervisorConfig{
 		HypervisorPath:        hypervisor,
 		KernelPath:            kernel,
+		InitrdPath:            initrd,
 		ImagePath:             image,
 		FirmwarePath:          firmware,
 		MachineAccelerators:   machineAccelerators,
@@ -393,6 +410,7 @@ func loadConfiguration(configPath string, ignoreLogging bool) (resolvedConfigPat
 		HypervisorPath:        defaultHypervisorPath,
 		KernelPath:            defaultKernelPath,
 		ImagePath:             defaultImagePath,
+		InitrdPath:            defaultInitrdPath,
 		FirmwarePath:          defaultFirmwarePath,
 		MachineAccelerators:   defaultMachineAccelerators,
 		HypervisorMachineType: defaultMachineType,

cli/config/configuration.toml.in

@@ -8,6 +8,7 @@
 [hypervisor.qemu]
 path = "@QEMUPATH@"
 kernel = "@KERNELPATH@"
+initrd = "@INITRDPATH@"
 image = "@IMAGEPATH@"
 machine_type = "@MACHINETYPE@"
 

cli/config_test.go

@@ -514,6 +514,7 @@ func TestMinimalRuntimeConfig(t *testing.T) {
 		HypervisorPath:        defaultHypervisorPath,
 		KernelPath:            defaultKernelPath,
 		ImagePath:             defaultImagePath,
+		InitrdPath:            defaultInitrdPath,
 		HypervisorMachineType: defaultMachineType,
 		DefaultVCPUs:          defaultVCPUCount,
 		DefaultMemSz:          defaultMemSize,
@@ -757,6 +758,44 @@ func TestHypervisorDefaultsKernel(t *testing.T) {
 	assert.Equal(h.kernelParams(), kernelParams, "custom hypervisor kernel parameterms wrong")
 }
 
+// The default initrd path is not returned by h.initrd()
+func TestHypervisorDefaultsInitrd(t *testing.T) {
+	assert := assert.New(t)
+
+	tmpdir, err := ioutil.TempDir(testDir, "")
+	assert.NoError(err)
+	defer os.RemoveAll(tmpdir)
+
+	testInitrdPath := filepath.Join(tmpdir, "initrd")
+	testInitrdLinkPath := filepath.Join(tmpdir, "initrd-link")
+
+	err = createEmptyFile(testInitrdPath)
+	assert.NoError(err)
+
+	err = syscall.Symlink(testInitrdPath, testInitrdLinkPath)
+	assert.NoError(err)
+
+	savedInitrdPath := defaultInitrdPath
+
+	defer func() {
+		defaultInitrdPath = savedInitrdPath
+	}()
+
+	defaultInitrdPath = testInitrdPath
+	h := hypervisor{}
+	p, err := h.initrd()
+	assert.NoError(err)
+	assert.Equal(p, "", "default Image path wrong")
+
+	// test path resolution
+	defaultInitrdPath = testInitrdLinkPath
+	h = hypervisor{}
+	p, err = h.initrd()
+	assert.NoError(err)
+	assert.Equal(p, "")
+}
+
+// The default image path is not returned by h.image()
 func TestHypervisorDefaultsImage(t *testing.T) {
 	assert := assert.New(t)
 
@@ -783,14 +822,14 @@ func TestHypervisorDefaultsImage(t *testing.T) {
 	h := hypervisor{}
 	p, err := h.image()
 	assert.NoError(err)
-	assert.Equal(p, defaultImagePath, "default Image path wrong")
+	assert.Equal(p, "", "default Image path wrong")
 
 	// test path resolution
 	defaultImagePath = testImageLinkPath
 	h = hypervisor{}
 	p, err = h.image()
 	assert.NoError(err)
-	assert.Equal(p, testImagePath)
+	assert.Equal(p, "")
 }
 
 func TestProxyDefaults(t *testing.T) {