freebsd-dev/sbin/bectl/bectl.8
Kyle Evans 7ce09314b2 bectl: use jail id as the default jail name for a boot environment
By default, bectl is setting the jail 'name' parameter to the boot
environment name, which causes an error when the boot environment name is
not a valid jail name. With the attached fix, when no name is supplied, the
default jail name will be the jail id - this is is the same behavior as the
jail command.

Additionally, this commit addresses two other bugs that prevented unjailing
in scenarios where the jail name does not match the boot environment name:

1. In 'bectl_locate_jail', 'mountpoint' is used to resolve the boot
  environment path, but really 'mounted' should be used. 'mountpoint' is the
  path where the zfs dataset will be mounted. 'mounted' is the path where
  the dataset is actually mounted.

2. in 'bectl_search_jail_paths', 'jail_getv' would fail after the first
  call. Which is fine, if the boot environment you're unjailing is the next
  one up. According to 'man jail_getv', it's expecting name and value
  strings. 'jail_getv' is being passed an integer for the lastjid, so amend
  that to use a string instead.

Test cases have been amended to reflect the bugs found.

PR:		233637
Submitted by:	Rob <rob.fx907_gmail.com>
MFC after:	3 days
Differential Revision:	https://reviews.freebsd.org/D18607
2018-12-25 15:18:41 +00:00

284 lines
5.8 KiB
Groff

.\"
.\" SPDX-License-Identifier: BSD-2-Clause-FreeBSD
.\"
.\" Copyright (c) 2017 Kyle J. Kneitinger <kyle@kneit.in>
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\"
.\" @(#)be.1
.\"
.\" $FreeBSD$
.\"
.Dd December 25, 2018
.Dt BECTL 8
.Os
.Sh NAME
.Nm bectl
.Nd Utility to manage Boot Environments on ZFS
.Sh SYNOPSIS
.Nm
.Cm activate
.Op Fl t
.Ar beName
.Nm
.Cm create
.Op Fl r
.Op Fl e Brq Ar nonActiveBe | beName@snapshot
.Ar beName
.Nm
.Cm create
.Op Fl r
.Ar beName@snapshot
.Nm
.Cm destroy
.Op Fl F
.Brq Ar beName | beName@snapshot
.Nm
.Cm export
.Ar sourceBe
.Nm
.Cm import
.Ar targetBe
.Nm
.Cm jail
.Brq Fl b | Fl U
.Oo Bro Fl o Ar key Ns = Ns Ar value | Fl u Ar key Brc Oc Ns ...
.Ar bootenv
.Op Ar utility Op Ar argument ...
.Nm
.Cm list
.Op Fl DHas
.Nm
.Cm mount
.Ar beName
.Op mountpoint
.Nm
.Cm rename
.Ar origBeName
.Ar newBeName
.Nm
.Brq Cm ujail | unjail
.Brq Ar jailID | jailName
.Ar bootenv
.Nm
.Brq Cm umount | unmount
.Op Fl f
.Ar beName
.Sh DESCRIPTION
The
.Nm
command is used to setup and interact with ZFS boot environments, which are
bootable clones of datasets.
.Pp
.Em Boot Environments
allows the system to be upgraded, while preserving the old system environment in
a separate ZFS dataset.
.Sh COMMANDS
The following commands are supported by
.Nm :
.Bl -tag -width activate
.It Xo
.Cm activate
.Op Fl t
.Ar beName
.Xc
Activate the given
.Ar beName
as the default boot filesystem.
If the
.Op Fl t
flag is given, this takes effect only for the next boot.
.It Xo
.Cm create
.Op Fl r
.Op Fl e Brq Ar nonActiveBe | beName@snapshot
.Ar beName
.Xc
Creates a new boot environment named
.Ar beName .
If the
.Fl e
argument is specified, the new environment will be cloned from the given
.Brq Ar nonActiveBe | Ar beName@snapshot .
If the
.Fl r
flag is given, a recursive boot environment will be made.
.It Xo
.Cm create
.Op Fl r
.Ar beName@snapshot
.Xc
Creates a snapshot of the existing boot environment named
.Ar beName .
If the
.Fl r
flag is given, a recursive boot environment will be made.
.It Xo
.Cm destroy
.Op Fl F
.Brq Ar beName | beName@snapshot
.Xc
Destroys the given
.Ar beName
boot environment or
.Ar beName@snapshot
snapshot without confirmation, unlike in
.Nm beadm .
Specifying
.Fl F
will automatically unmount without confirmation.
.It Cm export Ar sourceBe
Export
.Ar sourceBe
to
.Dv stdout .
.Dv stdout
must be piped or redirected to a file.
.It Cm import Ar targetBe
Import
.Ar targetBe
from
.Dv stdin .
.It Xo
.Cm jail
.Brq Fl b | Fl U
.Oo Bro Fl o Ar key Ns = Ns Ar value | Fl u Ar key Brc Oc Ns ...
.Ao Ar bootenv Ac
.Op Ar utility Op Ar argument ...
.Xc
Creates a jail of the given boot environment.
Multiple
.Fl o
and
.Fl u
arguments may be specified.
.Fl o
will set a jail parameter, and
.Fl u
will unset a jail parameter.
.Pp
By default, jails are created in interactive mode and
.Pa /bin/sh
is
executed within the jail.
If
.Ar utility
is specified, it will be executed instead of
.Pa /bin/sh .
The jail will be destroyed and the boot environment unmounted when the command
finishes executing, unless the
.Fl U
argument is specified.
.Pp
The
.Fl b
argument enables batch mode, thereby disabling interactive mode.
The
.Fl U
argument will be ignored in batch mode.
.Pp
The
.Va name ,
.Va host.hostname ,
and
.Va path
must be set, the default values are specified below.
.Pp
All
.Ar key Ns = Ns Ar value
pairs are interpreted as jail parameters as described in
.Xr jail 8 .
The following default parameters are provided:
.Bl -column "allow.mount.devfs" ""
.It Va allow.mount Ta Cm true
.It Va allow.mount.devfs Ta Cm true
.It Va enforce_statfs Ta Cm 1
.It Va name Ta jail id
.It Va host.hostname Ta Va bootenv
.It Va path Ta Set to a path in /tmp generated by
.Xr libbe 3 .
.El
.Pp
All default parameters may be overwritten.
.It Cm list Op Fl DHas
Displays all boot environments.
The Active field indicates whether the boot environment is active now (N);
active on reboot (R); or both (NR).
.Pp
If
.Fl a
is used, display all datasets.
If
.Fl D
is used, display the full space usage for each boot environment, assuming all
other boot environments were destroyed.
The
.Fl H
option is used for scripting.
It does not print headers and separate fields by a single tab instead of
arbitrary white space.
If
.Fl s
is used, display all snapshots as well.
.It Cm mount Ar beName Op Ar mountpoint
Temporarily mount the boot environment.
Mount at the specified
.Ar mountpoint
if provided.
.It Cm rename Ar origBeName newBeName
Renames the given
.Ar origBeName
to the given
.Ar newBeName .
The boot environment will not be unmounted in order for this rename to occur.
.It Cm unjail Brq Ar jailID | jailName | beName
Destroys the jail created from the given boot environment.
.It Xo
.Cm unmount
.Op Fl f
.Ar beName
.Xc
Unmount the given boot environment, if it is mounted.
Specifying
.Fl f
will force the unmount if busy.
.El
.Sh EXAMPLES
.Bl -bullet
.It
To fill in with jail upgrade example when behavior is firm.
.El
.Sh SEE ALSO
.Xr libbe 3 ,
.Xr jail 8 ,
.Xr zfs 8 ,
.Xr zpool 8
.Sh HISTORY
.Nm
is based on
.Nm beadm
and was implemented as a project for the 2017 Summer of Code, along with
.Xr libbe 3 .
.Sh AUTHORS
.Nm
was written by
.An Kyle Kneitinger (kneitinger) Aq Mt kyle@kneit.in .
.Pp
.Nm beadm
was written and is maintained by
.An Slawomir Wojciech Wojtczak (vermaden) Aq Mt vermaden@interia.pl .
.Pp
.An Bryan Drewery (bdrewery) Aq Mt bryan@shatow.net
wrote the original
.Nm beadm
manual page that this one is derived from.