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Launchpad Entry: friendly-recovery
Packages affected: whiptail, recovery-mode (new package), upstart-compat-sysv.
Summary
When the user selects the "(recovery mode)" item from the boot loader menu they will be taken to a ncurses-based menu where they can select a number of options to repair broken aspects of their system.
The items will be provided by scripts implementing a simple plug-in protocol. Packages can add menu items by simply putting a compliant script in the appropriate directory.
One such item will be "give me a root shell" so no functionality is lost with respect to the current behaviour.
Rationale
Currently when the "(recovery mode)" item is selected the user is dropped to a root shell. This is far from helpful.
Use Cases
- The user has forgotten their password and wants to reset it.
- The user has trashed their X config and wants to reconfig.
- The user has done a partial upgrade and their system isn't booting properly. They want to complete the upgrade.
- The user just wants a root shell prompt.
Scope
A new package "recovery-mode" will be created in main and included in the default install. A small change will be made to upstart to check for this script and invoke it instead of a shell in the event of a single user login. There may be changes to whiptail if it is missing required functionality.
Design
- /etc/event.d/rcS-sulogin checks for the existence of the executable /usr/share/recovery-mode/recovery-menu and invokes it if available or a shell otherwise.
- recovery-menu looks in /usr/share/recovery-mode/options
- each executable in this directory is invoked with the "test" command-line parameter.
- if it returns zero it should print a name to stdout to be added to the menu
- like "Recover broken X configuration".
- if it returns one it will not be added to the menu
- makes sense if the script detects that nothing is broken
- if it returns zero it should print a name to stdout to be added to the menu
- the menu is shown with the items that returned zero along with their names
- when the user picks an item the same script is executed with no parameters
- when the script exits, the "test"ing is redone and the user is returned to the menu
- if the script exits with a status of 42 (magic number) then the boot-up immediately resumes
- this should not normally be used
- it is for things like "continue boot with safe video mode"
Implementation
Implementation is in progress. Some other package maintainers have been notified and plan to provide their own plug-in scripts.