Files
kata-containers/image-builder
Stefan Hajnoczi 7b1bbac600 image-builder: require root earlier for better error messages
The image_builder.sh script must be run as root.  The following check is
performed before the script checks for root:

  [ "${AGENT_INIT}" == "yes" ] || [ -x "${ROOTFS}/usr/bin/${AGENT_BIN}" ] || \
      die "/usr/bin/${AGENT_BIN} is not installed in ${ROOTFS}
      use AGENT_BIN env variable to change the expected agent binary name"

The -x test is "True if the file is executable by you".  It may evaluate
to true as root and false as non-root, depending on the file
permissions.

The permissions for kata-agent given in the Developer Guide are 0550
(https://github.com/kata-containers/documentation/blob/master/Developer-Guide.md#add-a-custom-agent-to-the-image---optional).

Therefore image_builder.sh fails with "/usr/bin/${AGENT_BIN} is not
installed" when run as non-root.  This is confusing since the agent
binary is really installed!

Move the root check to the beginning of the script.  This solves the
confusing error and prevents similar problems where the script doesn't
take into account that the user may be non-root.

Fixes: #127
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-06-28 14:16:26 +01:00
..
2018-05-18 13:01:08 +01:00

Kata Containers image generation

A Kata Containers disk image is generated using the image_builder.sh script. This uses a rootfs directory created by the rootfs-builder/rootfs.sh script.

Creating a guest OS image

To create a guest OS image run:

$ sudo ./image_builder.sh path/to/rootfs

Where path/to/rootfs is the directory populated by rootfs.sh.

Note

: If you are building an image from an Alpine rootfs, see the important note here.

Further information

For more information about usage (including how to adjust the size of the image), run:

$ ./image_builder.sh -h