From a3978bc89d255a9f83f9a7354e720d46e78424fd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fredrik=20L=C3=B6nnegren?= <fredrik.lonnegren@suse.com>
Date: Thu, 14 Dec 2023 09:47:58 +0100
Subject: [PATCH] Read mount env-vars before kernel-cmdline
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Fredrik Lönnegren <fredrik.lonnegren@suse.com>
---
 cmd/config/config.go                          | 51 ++++++++++++++-----
 cmd/config/config_test.go                     |  9 +++-
 pkg/constants/constants.go                    |  6 +--
 .../system/oem/00_rootfs.yaml                 |  2 +-
 4 files changed, 49 insertions(+), 19 deletions(-)

diff --git a/cmd/config/config.go b/cmd/config/config.go
index c04d47b53a0..1142d677b89 100644
--- a/cmd/config/config.go
+++ b/cmd/config/config.go
@@ -317,6 +317,11 @@ func applyKernelCmdline(r *v1.RunConfig, mount *v1.MountSpec) error {
 				r.Logger.Errorf("Error parsing cmdline %s", cmd)
 				return errors.New("Unknown image path")
 			}
+		case "elemental.overlay", "rd.cos.overlay":
+			err := applyMountOverlay(mount, val)
+			if err != nil {
+				return err
+			}
 		case "elemental.oemlabel", "rd.cos.oemlabel":
 			mount.Partitions.OEM.FilesystemLabel = val
 		}
@@ -332,19 +337,9 @@ func applyMountEnvVars(r *v1.RunConfig, mount *v1.MountSpec) error {
 	if overlay != "" {
 		r.Logger.Debugf("Setting ephemeral settings based on OVERLAY")
 
-		split := strings.Split(overlay, ":")
-		if len(split) != 2 {
-			return fmt.Errorf("Unknown format of OVERLAY env-var: %s", overlay)
-		}
-
-		mount.Ephemeral.Type = split[0]
-
-		if split[0] == constants.Tmpfs {
-			mount.Ephemeral.Size = split[1]
-		}
-
-		if split[0] == constants.Block {
-			mount.Ephemeral.Device = split[1]
+		err := applyMountOverlay(mount, overlay)
+		if err != nil {
+			return err
 		}
 	}
 
@@ -369,6 +364,36 @@ func applyMountEnvVars(r *v1.RunConfig, mount *v1.MountSpec) error {
 	return nil
 }
 
+func applyMountOverlay(mount *v1.MountSpec, overlay string) error {
+	split := strings.Split(overlay, ":")
+
+	if len(split) == 2 && split[0] == constants.Tmpfs {
+		mount.Ephemeral.Device = ""
+		mount.Ephemeral.Type = split[0]
+		mount.Ephemeral.Size = split[1]
+		return nil
+	}
+
+	mount.Ephemeral.Type = constants.Block
+	mount.Ephemeral.Size = ""
+
+	blockSplit := strings.Split(overlay, "=")
+	if len(blockSplit) != 2 {
+		return fmt.Errorf("Unknown block overlay '%s'", overlay)
+	}
+
+	switch blockSplit[0] {
+	case "LABEL":
+		mount.Ephemeral.Device = fmt.Sprintf("/dev/disk/by-label/%s", blockSplit[1])
+	case "UUID":
+		mount.Ephemeral.Device = fmt.Sprintf("/dev/disk/by-uuid/%s", blockSplit[1])
+	default:
+		return fmt.Errorf("Unknown block overlay '%s'", overlay)
+	}
+
+	return nil
+}
+
 func ReadResetSpec(r *v1.RunConfig, flags *pflag.FlagSet) (*v1.ResetSpec, error) {
 	reset, err := config.NewResetSpec(r.Config)
 	if err != nil {
diff --git a/cmd/config/config_test.go b/cmd/config/config_test.go
index 48640e79491..e361fa2cef8 100644
--- a/cmd/config/config_test.go
+++ b/cmd/config/config_test.go
@@ -273,7 +273,7 @@ var _ = Describe("Config", Label("config"), func() {
 
 			err = fs.Mkdir("/proc", constants.DirPerm)
 			Expect(err).Should(BeNil())
-			err = fs.WriteFile("/proc/cmdline", []byte("root=LABEL=COS_STATE elemental.image=active"), 0444)
+			err = fs.WriteFile("/proc/cmdline", []byte("root=LABEL=COS_STATE elemental.image=active elemental.overlay=tmpfs:30%"), 0444)
 			Expect(err).Should(BeNil())
 
 			cfg, err = ReadConfigRun("fixtures/config/", nil, mounter)
@@ -469,6 +469,13 @@ var _ = Describe("Config", Label("config"), func() {
 				// Set by kernel cmdline
 				Expect(spec.Mode).To(Equal("active"))
 			})
+			It("picks kernel cmdline first then env-vars", func() {
+				err := os.Setenv("OVERLAY", "UUID=1234")
+				spec, err := ReadMountSpec(cfg, nil)
+				Expect(err).ShouldNot(HaveOccurred())
+				Expect(spec.Ephemeral.Type).To(Equal("tmpfs"))
+				Expect(spec.Ephemeral.Size).To(Equal("30%"))
+			})
 		})
 	})
 })
diff --git a/pkg/constants/constants.go b/pkg/constants/constants.go
index 4a82628d209..6f9549fc276 100644
--- a/pkg/constants/constants.go
+++ b/pkg/constants/constants.go
@@ -263,10 +263,8 @@ func GetInitKeyEnvMap() map[string]string {
 // GetMountKeyEnvMap returns environment variable bindings to MountSpec data
 func GetMountKeyEnvMap() map[string]string {
 	return map[string]string{
-		"write-fstab":         "WRITE_FSTAB",
-		"write-sentinel":      "WRITE_SENTINEL",
-		"sysroot":             "SYSROOT",
-		"read-kernel-cmdline": "READ_KERNEL_CMDLINE",
+		"write-fstab": "WRITE_FSTAB",
+		"sysroot":     "SYSROOT",
 	}
 }
 
diff --git a/pkg/features/embedded/cloud-config-essentials/system/oem/00_rootfs.yaml b/pkg/features/embedded/cloud-config-essentials/system/oem/00_rootfs.yaml
index 445d8a841ed..93daa5b3fa9 100644
--- a/pkg/features/embedded/cloud-config-essentials/system/oem/00_rootfs.yaml
+++ b/pkg/features/embedded/cloud-config-essentials/system/oem/00_rootfs.yaml
@@ -15,7 +15,7 @@ stages:
   rootfs:
     - if: '[ ! -f "/run/elemental/recovery_mode" ]'
       name: "Layout configuration"
-      environment_file: /run/elemental/mount-layout.env
+      environment_file: /run/cos/cos-layout.env
       environment:
         OVERLAY: "tmpfs:25%"
   initramfs: