NCM::Component::grub

NAME

The grub component manages the grub configuration.

DESCRIPTION

The grub component manages the configuration of grub.

Most of the configuration is handled via the grubby tool (which supports grub2).

Some configuration like serial console settings and password however is done by modifying the grub configfile directly, which might not be safe under grub2.

RESOURCES

Besides /software/component/grub, following resources are used:

  • /system/kernel/version for setting the default kernel

  • /hardware/console/serial for serial console configuration

EXAMPLES

  • A standard SL4 kernel with initrd image to be loaded.

"/software/components/grub/kernels/0" =
      nlist("kernelpath", "/vmlinuz-2.6.9-22.0.1.EL",
            "kernelargs", "ro root=LABEL=/",
            "title", "Scientific Linux 4.2 / 2.6.9",
            "initrd", "/initrd-2.6.9-22.0.1.EL.img"
);

This configuration produces the following entry in grub.conf (via grubby):

title Scientific Linux 4.2 / 2.6.9
      kernel `/vmlinuz`-2.6.9-22.0.1.EL ro root=LABEL=/
      initrd `/initrd`-2.6.9-22.0.1.EL.img

  • A Xen 3 hypervisor with Linux 2.6 domain 0 kernel and initrd (via grubby).

"/software/components/grub/kernels/1" =
      nlist("multiboot", "/xen-3.0.2-2.gz",
            "mbargs", "dom0_mem=400000",
            "title", "Xen 3 / XenLinux 2.6.16",
            "kernelpath", "/vmlinuz-2.6.16-xen3_86.1_rhel4.1",
            "kernelargs", "max_loop=128 root=/dev/hda2 ro",
            "initrd", "/initrd-2.6.16-xen3_86.1_rhel4.1"
);

Produces the following entry in grub.conf:

title Xen 3 / XenLinux 2.6.16
      kernel `/xen`-3.0.2-2.gz dom0_mem=400000 addthis
      module `/vmlinuz`-2.6.16-xen3_86.1_rhel4.1 max_loop=128 root=/dev/hda2 ro
      module `/initrd`-2.6.16-xen3_86.1_rhel4.1

Methods

  • convert_grubby_arguments

Given args string or hashref, update arguments hashref with add/remove hashrefs. Optional serial console kernel commandline option cons

If args is a string, arguments prefixed with ‘-’ are added to the remove hashref.

Returns arguments hashref with add and remove hashrefs.

If track is false, the values of add and remove hashrefs are the last encountered value. If track is true, the values of add and remove hashrefs are arraysrefs with all encountered values.

  • assemble_grubby_options

Given arguments hashref, return the add and remove option arrayrrefs.

  • grubby_arguments_options

Given arguments hashref args, convert into grubby commandline options to add and/or remove the arguments. If multiboot is true, generate multiboot commandline options

Returns a list of options.

  • password

Configure the grub password by editing the grub conf via filehandle grub_fh (a CAF::FileEditor instance, which is not closed in this method).

Returns SUCCESS on succes, undef otherwise.

  • serial_console

Configure the grub serial console settings (ttyS devices only) by editing the grub conf via filehandle grub_fh (a CAF::FileEditor instance, which is not closed in this method).

Returns undef on failure, the console kernel commandline option (or empty string if none is to be configured) on success.

  • main_section_offset

Given a grub config filehandle (a CAF::FileEditor instance), return the startposition of the main section i.e. after the header comments (if any).

  • grub_conf

Edit grub configfile and return serial console kernel commandline option (if any).

  • grubby

Run grubby with arraref args via CAF::Proces using the output method and return the output.

Has following options

  • proc: return new CAF::Process instance with args (i.e. without execute/output)

  • success: run execute and return 1 on success, 0 on failure

  • keeps_state: pass keeps_state flag

  • current_default

Return current full path of current default kernel.

  • set_default

Set default kernel to new kernelpath and verify by (re)checking the default kernel.

Returns success on success; on failure, return either

  • undef: setting default kernel returned non-zero exitcode

  • 0: setting default was succesful, but new default kernel is not expected kernel

No errors are reported.

  • configure_default

Configure the new default kernel to be new. If this fails and mbnew exists, try to set mbnew as default.

If neither new nor mbnew are successful, report an error and revert to original.

  • kernel

Configure boot entry using kernel hashref, the kernel prefix and optional serial console kernel commandline option cons.

Any serial console settings in the kernelargs attribute is replaced by cons (when defined).

  • get_info

Return info for default kernel as an arrayref of hashref

Same kernel can have multiple entries.

  • current_arguments

Get the current arguments. Return current arguments as string and as parsed hasref

track option is passed to convert_grubby_arguments.

  • sanitize_arguments

Sanitize the current arguments

  • default_options

Configure kernel commandline options of default kernel

  • pxeboot

Set pxeboot as first bootorder. Returns SUCCESS on success, undef otherwise.

Currently only supported on UEFI systems using efibootmgr. On other systems, SUCCESS is also returned (but nothing is done).

  • Configure

Updates the grub.conf configuration file using grubby according to a list of kernels described in the profile.

Sets the default kernel to that specified in /system/kernel/version.

Supports

  • serial console configuration specified in /hardware/console/serial.

  • multiboot loaders (most commonly used for configuration of Xen systems).

Returns error in case of failure.