Define the mountpoint on the golang side.

Then plumb that through to the script. This means that logic on the
golang side owns the knowledge of the mountpoint, and doesn't need to
assume that it knows what the mountpoint is from the shell script.

For now, this is only done on the `gce_install_cuttlefish_packages`
command.

Author: 3405691582

tools/baseimage/cmd/gce_install_cuttlefish_packages/main.go

@@ -30,6 +30,7 @@ import (
 
 const (
 	outImageName = "amended-image"
+	mountpoint   = "/mnt/image"
 )
 
 type DebSrcsFlag struct {
@@ -90,11 +91,8 @@ func fillAvailableSpace(project, zone, insName string) error {
 	return gce.RunCmd(project, zone, insName, "./fill_available_disk_space.sh")
 }
 
-func mountAttachedDisk(project, zone, insName string) (string, error) {
-	if err := gce.RunCmd(project, zone, insName, "./mount_attached_disk.sh"); err != nil {
-		return "", err
-	}
-	return "/mnt/image/", nil
+func mountAttachedDisk(project, zone, insName, mountpoint string) error {
+	return gce.RunCmd(project, zone, insName, "./mount_attached_disk.sh "+mountpoint)
 }
 
 func installCuttlefishDebs(project, zone, insName string, debSrcs []string) error {
@@ -185,7 +183,7 @@ func amendImageMain(project, zone string, opts amendImageOpts) error {
 		return fmt.Errorf("fillAvailableSpace error: %v", err)
 	}
 
-	if _, err := mountAttachedDisk(project, zone, insName); err != nil {
+	if err := mountAttachedDisk(project, zone, insName, mountpoint); err != nil {
 		return fmt.Errorf("mountAttachedDisk error: %v", err)
 	}
 

tools/baseimage/pkg/gce/scripts/create_base_image_main.sh

@@ -30,7 +30,7 @@ sudo growpart /dev/sdb 1 || /bin/true
 sudo e2fsck -f -y /dev/sdb1 || /bin/true
 sudo resize2fs /dev/sdb1
 
-./mount_attached_disk.sh
+./mount_attached_disk.sh /mnt/image
 
 kmodver_begin=$(sudo chroot /mnt/image/ /usr/bin/dpkg -s linux-image-cloud-amd64 | grep ^Depends: | \
   cut -d: -f2 | cut -d" " -f2 | sed 's/linux-image-//')

tools/baseimage/pkg/gce/scripts/install_kernel_main.sh

@@ -26,7 +26,7 @@ linux_image_deb=$1
 sudo apt-get update
 sudo apt-get upgrade -y
 
-./mount_attached_disk.sh
+./mount_attached_disk.sh /mnt/image
 
 version=$(sudo chroot /mnt/image/ /usr/bin/dpkg -s linux-image-cloud-amd64 | grep ^Depends: | \
   cut -d: -f2 | cut -d" " -f2 )

tools/baseimage/pkg/gce/scripts/mount_attached_disk.sh

@@ -14,19 +14,21 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Mount attached disk `/dev/sdb1` at `/mnt/image`.
+# Mount attached disk `/dev/sdb1` at `/mnt/image` (the argument).
 set -o errexit -o nounset -o pipefail
 
-sudo mkdir -p /mnt/image
-sudo mount /dev/sdb1 /mnt/image
-sudo mount -t sysfs none /mnt/image/sys
-sudo mount -t proc none /mnt/image/proc
-sudo mount --bind /boot/efi /mnt/image/boot/efi
-sudo mount --bind /dev/ /mnt/image/dev
-sudo mount --bind /dev/pts /mnt/image/dev/pts
-sudo mount --bind /run /mnt/image/run
+MOUNTPONT=$1
+
+sudo mkdir -p ${MOUNTPOINT}
+sudo mount /dev/sdb1 ${MOUNTPOINT}
+sudo mount -t sysfs none ${MOUNTPOINT}/sys
+sudo mount -t proc none ${MOUNTPOINT}/proc
+sudo mount --bind /boot/efi ${MOUNTPOINT}/boot/efi
+sudo mount --bind /dev/ ${MOUNTPOINT}/dev
+sudo mount --bind /dev/pts ${MOUNTPOINT}/dev/pts
+sudo mount --bind /run ${MOUNTPOINT}/run
 # resolv.conf is needed on Debian but not Ubuntu
-if [ ! -f /mnt/image/etc/resolv.conf ]; then
-  sudo cp /etc/resolv.conf /mnt/image/etc/
+if [ ! -f ${MOUNTPOINT}/etc/resolv.conf ]; then
+  sudo cp /etc/resolv.conf ${MOUNTPOINT}/etc/
 fi
 `