[fedora-virt] ANNOUNCE: Augeas support added to libguestfs

[Richard W.M. Jones]

Augeas, meet libguestfs.

Libguestfs is a library I'm writing which lets you examine and modify
virtual machine disk images, so you can perform sysadmin tasks on
virtual machines without needing to bring them up or log into them.

As of a few minutes ago, libguestfs now supports Augeas, so you can
use Augeas to edit configuration files within the virtual machine.
You will need the git version of libguestfs to get this at the moment,
or it will appear in version 0.7 when I release it.

  http://et.redhat.com/~rjones/libguestfs/
  http://git.et.redhat.com/?p=libguestfs.git;a=summary

Here's an example session using the shell tool, editing the /etc/hosts
file from a RHEL 5.2 virtual machine:

  $ guestfish -a RHEL52PV32.img -m /dev/VolGroup00/LogVol00 
  
  Welcome to guestfish, the libguestfs filesystem interactive shell for
  editing virtual machine filesystems.
  
  Type: 'help' for help with commands
        'quit' to quit the shell
  
  ><fs> aug-init / 0
  ><fs> aug-match /augeas/*
  /augeas/root
  /augeas/save
  /augeas/files
  ><fs> aug-match /files//error
  ><fs> aug-match /augeas//error
  ><fs> aug-match /augeas/root/*
  ><fs> aug-match /files/etc/*
  /files/etc/ldap.conf
  /files/etc/aliases
  /files/etc/yum.repos.d
  /files/etc/yum.conf
  /files/etc/sysconfig
  /files/etc/default
  /files/etc/inittab
  /files/etc/sysctl.conf
  /files/etc/hosts
  /files/etc/pam.d
  /files/etc/logrotate.d
  /files/etc/samba
  /files/etc/xinetd.conf
  /files/etc/xinetd.d
  /files/etc/fstab
  /files/etc/ssh
  /files/etc/exports
  ><fs> aug-match /files/etc/hosts/*
  /files/etc/hosts/comment[1]
  /files/etc/hosts/comment[2]
  /files/etc/hosts/1
  /files/etc/hosts/2
  ><fs> cat /etc/hosts                   
  # Do not remove the following line, or various programs
  # that require network functionality will fail.
  127.0.0.1      	       localhost.localdomain localhost
  ::1		               localhost6.localdomain6 localhost6
  
  ><fs> aug-get /files/etc/hosts/comment[1]  
  Do not remove the following line, or various programs
  ><fs> help aug-insert
  aug-insert - insert a sibling Augeas node
       aug-insert <path> <label> <before>
  
      Create a new sibling "label" for "path", inserting it into the tree
      before or after "path" (depending on the boolean flag "before").
  
      "path" must match exactly one existing node in the tree, and "label"
      must be a label, ie. not contain "/", "*" or end with a bracketed index
      "[N]".
  
  ><fs> aug-insert /files/etc/hosts/comment[2] comment false
  ><fs> aug-match /files/etc/hosts/*
  /files/etc/hosts/comment[1]
  /files/etc/hosts/comment[2]
  /files/etc/hosts/comment[3]
  /files/etc/hosts/1
  /files/etc/hosts/2
  ><fs> aug-set /files/etc/hosts/comment[3] HELLO
  ><fs> aug-save
  ><fs> cat /etc/hosts 
  # Do not remove the following line, or various programs
  # that require network functionality will fail.
  # HELLO
  127.0.0.1		localhost.localdomain localhost
  ::1			localhost6.localdomain6 localhost6
  
  ><fs> help
      Command              Description
  help                 display a list of commands or help on a command
  quit                 quit guestfish
  alloc                allocate an image
  add-cdrom            add a CD-ROM disk image to examine
  add-drive            add an image to examine or modify
  aug-close            close the current Augeas handle
  aug-defnode          define an Augeas node
  aug-defvar           define an Augeas variable
  aug-get              look up the value of an Augeas path
  aug-init             create a new Augeas handle
  aug-insert           insert a sibling Augeas node
  aug-load             load files into the tree
  aug-match            return Augeas nodes which match path
  aug-mv               move Augeas node
  aug-rm               remove an Augeas path
  aug-save             write all pending Augeas changes to disk
  aug-set              set Augeas path to value
  cat                  list the contents of a file
  config               add qemu parameters
  get-autosync         get autosync mode
  get-path             get the search path
  get-verbose          get verbose mode
  kill-subprocess      kill the qemu subprocess
  launch               launch the qemu subprocess
  list-devices         list the block devices
  list-partitions      list the partitions
  ll                   list the files in a directory (long format)
  ls                   list the files in a directory
  lvs                  list the LVM logical volumes (LVs)
  lvs-full             list the LVM logical volumes (LVs)
  mount                mount a guest disk at a position in the filesystem
  pvs                  list the LVM physical volumes (PVs)
  pvs-full             list the LVM physical volumes (PVs)
  read-lines           read file as lines
  set-autosync         set autosync mode
  set-path             set the search path
  set-verbose          set verbose mode
  sync                 sync disks, writes are flushed through to the disk image
  touch                update file timestamps or create a new file
  vgs                  list the LVM volume groups (VGs)
  vgs-full             list the LVM volume groups (VGs)
      Use -h <cmd> / help <cmd> to show detailed help for a command.

Rich.

-- 
Richard Jones, Emerging Technologies, Red Hat  http://et.redhat.com/~rjones
virt-top is 'top' for virtual machines.  Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://et.redhat.com/~rjones/virt-top