This change documents the existance of the systemd-nspawn@.service template
unit file, which was previously not mentioned at all. Since the unit file uses
slightly different default than nspawn invoked from the command line, these
defaults are now explicitly documented too.
A couple of further additions and changes are made, too.
Replaces: #3497
This the patch implements a notificaiton mechanism from the init process
in the container to systemd-nspawn.
The switch --notify-ready=yes configures systemd-nspawn to wait the "READY=1"
message from the init process in the container to send its own to systemd.
--notify-ready=no is equivalent to the previous behavior before this patch,
systemd-nspawn notifies systemd with a "READY=1" message when the container is
created. This notificaiton mechanism uses socket file with path relative to the contanier
"/run/systemd/nspawn/notify". The default values it --notify-ready=no.
It is also possible to configure this mechanism from the .nspawn files using
NotifyReady. This parameter takes the same options of the command line switch.
Before this patch, systemd-nspawn notifies "ready" after the inner child was created,
regardless the status of the service running inside it. Now, with --notify-ready=yes,
systemd-nspawn notifies when the service is ready. This is really useful when
there are dependencies between different contaniers.
Fixes https://github.com/systemd/systemd/issues/1369
Based on the work from https://github.com/systemd/systemd/pull/3022
Testing:
Boot a OS inside a container with systemd-nspawn.
Note: modify the commands accordingly with your filesystem.
1. Create a filesystem where you can boot an OS.
2. sudo systemd-nspawn -D ${HOME}/distros/fedora-23/ sh
2.1. Create the unit file /etc/systemd/system/sleep.service inside the container
(You can use the example below)
2.2. systemdctl enable sleep
2.3 exit
3. sudo systemd-run --service-type=notify --unit=notify-test
${HOME}/systemd/systemd-nspawn --notify-ready=yes
-D ${HOME}/distros/fedora-23/ -b
4. In a different shell run "systemctl status notify-test"
When using --notify-ready=yes the service status is "activating" for 20 seconds
before being set to "active (running)". Instead, using --notify-ready=no
the service status is marked "active (running)" quickly, without waiting for
the 20 seconds.
This patch was also test with --private-users=yes, you can test it just adding it
at the end of the command at point 3.
------ sleep.service ------
[Unit]
Description=sleep
After=network.target
[Service]
Type=oneshot
ExecStart=/bin/sleep 20
[Install]
WantedBy=multi-user.target
------------ end ------------
We check /etc/machine-id of the container and if it is already populated
we use value from there, possibly ignoring value of --uuid option from
the command line. When dealing with R/O image we setup transient machine
id.
Once we determined machine id of the container, we use this value for
registration with systemd-machined and we also export it via
container_uuid environment variable.
As registration with systemd-machined is done by the main nspawn process
we communicate container machine id established by setup_machine_id from
outer child to the main process by unix domain socket. Similarly to PID
of inner child.
This adds a new switch --as-pid2, which allows running commands as PID 2, while a stub init process is run as PID 1.
This is useful in order to run arbitrary commands in a container, as PID1's semantics are different from all other
processes regarding reaping of unknown children or signal handling.
The new switch operates like --network-veth, but may be specified
multiple times (to define multiple link pairs) and allows flexible
definition of the interface names.
This is an independent reimplementation of #1678, but defines different
semantics, keeping the behaviour completely independent of
--network-veth. It also comes will full hook-up for .nspawn files, and
the matching documentation.
Technically, it's safer that way, since dnf is supposed to parse the
"*", not the shell. It doesn't really matter too much in real life (as
the expression is too complex), but let's better be safe than sorry, and
make sure people won't file bugs about this...
Without the updates repo, we are installing packages from the time
that that version of Fedora was released. Normally, during the
lifetime of the release most packages are updated, so most of the
packages installed would be outdated, and the first update after
installation would update a massive set of packages. Avoid all this
by installing from the updates repo from the start.
Keys for previous and future Fedora distributions were added
for the fedora-repos package recently:
https://bugzilla.redhat.com/show_bug.cgi?id=1246701.
There is no need to skip signature checking.
Also, update to the latest and greatest and remove unnecessary quotes.
.nspawn fiels are simple settings files that may accompany container
images and directories and contain settings otherwise passed on the
nspawn command line. This provides an efficient way to attach execution
data directly to containers.
--bind and --bind-ro perform the bind mount
non-recursively. It is sometimes (often?) desirable
to do a recursive mount. This patch adds an optional
set of bind mount options in the form of:
--bind=src-path:dst-path:options
options are comma separated and currently only
"rbind" and "norbind" are allowed.
Default value is "rbind".
The --machine option used to describe searching for machines in
/var/lib/machines, which is not the whole story, so let's link to where
it's described in more detail.
This did not really work out as we had hoped. Trying to do this upstream
introduced several problems that probably makes it better suited as a
downstream patch after all. At any rate, it is not releaseable in the
current state, so we at least need to revert this before the release.
* by adjusting the path to binaries, but not do the same thing to the
search path we end up with inconsistent man-pages. Adjusting the search
path too would be quite messy, and it is not at all obvious that this is
worth the effort, but at any rate it would have to be done before we
could ship this.
* this means that distributed man-pages does not make sense as they depend
on config options, and for better or worse we are still distributing
man pages, so that is something that definitely needs sorting out before
we could ship with this patch.
* we have long held that split-usr is only minimally supported in order
to boot, and something we hope will eventually go away. So before we start
adding even more magic/effort in order to make this work nicely, we should
probably question if it makes sense at all.
In particular, use /lib/systemd instead of /usr/lib/systemd in distributions
like Debian which still have not adopted a /usr merge setup.
Use XML entities from man/custom-entities.ent to replace configured paths while
doing XSLT processing of the original XML files. There was precedent of some
files (such as systemd.generator.xml) which were already using this approach.
This addresses most of the (manual) fixes from this patch:
http://anonscm.debian.org/cgit/pkg-systemd/systemd.git/tree/debian/patches/Fix-paths-in-man-pages.patch?h=experimental-220
The idea of using generic XML entities was presented here:
http://lists.freedesktop.org/archives/systemd-devel/2015-May/032240.html
This patch solves almost all the issues, with the exception of:
- Path to /bin/mount and /bin/umount.
- Generic statements about preference of /lib over /etc.
These will be handled separately by follow up patches.
Tested:
- With default configure settings, ran "make install" to two separate
directories and compared the output to confirm they matched exactly.
- Used a set of configure flags including $CONFFLAGS from Debian:
http://anonscm.debian.org/cgit/pkg-systemd/systemd.git/tree/debian/rules
Installed the tree and confirmed the paths use /lib/systemd instead of
/usr/lib/systemd and that no other unexpected differences exist.
- Confirmed that `make distcheck` still passes.
Previously all bind mount mounts were applied in the order specified,
followed by all tmpfs mounts in the order specified. This is
problematic, if bind mounts shall be placed within tmpfs mounts.
This patch hence reworks the custom mount point logic, and alwas applies
them in strict prefix-first order. This means the order of mounts
specified on the command line becomes irrelevant, the right operation
will always be executed.
While we are at it this commit also adds native support for overlayfs
mounts, as supported by recent kernels.
Previously, the man page suggested to only use nspawn for testing,
building, and debugging things. However, it is nowadays used in
production and used as building block for rocket, hence let's just admit
that it's pretty much production ready.
Given that this is also the place to store raw disk images which are
very much bootable with qemu/kvm it sounds like a misnomer to call the
directory "container". Hence, let's change this sooner rather than
later, and use the generic name, in particular since we otherwise try to
use the generic "machine" preferably over the more specific "container"
or "vm".
Now that networkd's IP masquerading support means that running
containers with "--network-veth" will provide network access out of the
box for the container, let's add a shortcut "-n" for it, to make it
easily accessible.
Also, when booting up an ephemeral container of / use the system
hostname as default machine name.
This way specifiyng -M is unnecessary when booting up an ephemeral
container, while allowing any number of ephemeral containers to run from
the same tree.
This adds --template= to duplicate an OS tree as btrfs snpashot and run
it
This also adds --ephemeral or -x to create a snapshot of an OS tree and
boot that, removing it after exit.
--link-journal={host,guest} fail if the host does not have persistent
journalling enabled and /var/log/journal/ does not exist. Even worse, as there
is no stdout/err any more, there is no error message to point that out.
Introduce two new modes "try-host" and "try-guest" which don't fail in this
case, and instead just silently skip the guest journal setup.
Change -j to mean "try-guest" instead of "guest", and fix the wrong --help
output for it (it said "host" before).
Change systemd-nspawn@.service.in to use "try-guest" so that this unit works
with both persistent and non-persistent journals on the host without failing.
https://bugs.debian.org/770275
It is annoying when we have dead links on fd.o.
Add project='man-pages|die-net|archlinux' to <citerefentry>-ies.
In generated html, add external links to
http://man7.org/linux/man-pages/man, http://linux.die.net/man/,
https://www.archlinux.org/.
By default, pages in sections 2 and 4 go to man7, since Michael
Kerrisk is the autorative source on kernel related stuff.
The rest of links goes to linux.die.net, because they have the
manpages.
Except for the pacman stuff, since it seems to be only available from
archlinux.org.
Poor gummiboot gets no link, because gummitboot(8) ain't to be found
on the net. According to common wisdom, that would mean that it does
not exist. But I have seen Kay using it, so I know it does, and
deserves to be found. Can somebody be nice and put it up somewhere?
The file should have been in /usr/lib/ in the first place, since it
describes the OS container in /usr (and not the configuration in /etc),
hence, let's support os-release files in /usr/lib as fallback if no
version in /etc exists, following the usual override logic.
A prior commit already enabled tmpfiles to create /etc/os-release as a
symlink to /usr/lib/os-release should it be missing, thus providing nice
compatibility with applications only checking in /etc.
While it's probably a good idea if all apps check both locations via a
fallback logic, it is only necessary in the early boot process, as long
as the /etc/os-release symlink has not been restored, in case we boot
with an empty /etc.
Issues fixed:
* missing words required by grammar
* duplicated or extraneous words
* inappropriate forms (e.g. singular/plural), and declinations
* orthographic misspellings
This adds the host side of the veth link to the given bridge.
Also refactor the creation of the veth interfaces a bit to set it up
from the host rather than the container. This simplifies the addition
to the bridge, but otherwise the behavior is unchanged.
Let's always call the security labels the same way:
SMACK: "Smack Label"
SELINUX: "SELinux Security Context"
And the low-level encapsulation is called "seclabel". Now let's hope we
stick to this vocabulary in future, too, and don't mix "label"s and
"security contexts" and so on wildly.
- As suggested, prefix argument variables with "arg_" how we do this
usually.
- As suggested, don't involve memory allocations when storing command
line arguments.
- Break --help text at 80 chars
- man: explain that this is about SELinux
- don't do unnecessary memory allocations when putting together mount
option string
This patch adds to new options:
-Z PROCESS_LABEL
This specifies the process label to run on processes run within the container.
-L FILE_LABEL
The file label to assign to memory file systems created within the container.
For example if you wanted to wrap an container with SELinux sandbox labels, you could execute a command line the following
chcon system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 -R /srv/container
systemd-nspawn -L system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 -Z system_u:system_r:svirt_lxc_net_t:s0:c0,c1 -D /srv/container /bin/sh
This is a recurring submission and includes corrections to various
issue spotted. I guess I can just skip over reporting ubiquitous
comma placement fixes…
Highligts in this particular commit:
- the "unsigned" type qualifier is completed to form a full type
"unsigned int"
- alphabetic -> lexicographic (that way we automatically define how
numbers get sorted)
This includes regularly-submitted corrections to comma setting and
orthographical mishaps that appeared in man/ in recent commits.
In this particular commit:
- the usual comma fixes
- expand contractions (this is prose)
Use proper grammar, word usage, adjective hyphenation, commas,
capitalization, spelling, etc.
To improve readability, some run-on sentences or sentence fragments were
revised.
[zj: remove the space from 'file name', 'host name', and 'time zone'.]
Everything which is an absolute filename marked with <filename></filename>
lands in the index, unless noindex= attribute is present. Should make
it easier for people to find stuff when they are looking at a file on
disk.
Various formatting errors in manpages are fixed, kernel-install(1) is
restored to formatting sanity.
Apparently nsenter doesn't handle options concatenated together.
I'm pretty sure it worked at one point, but it seems like magic,
since each of those options can take arguments.
Containers will now carry a label (normally derived from the root
directory name, but configurable by the user), and the container's root
cgroup is /machine/<label>. This label is called "machine name", and can
cover both containers and VMs (as soon as libvirt also makes use of
/machine/).
libsystemd-login can be used to query the machine name from a process.
This patch also includes numerous clean-ups for the cgroup code.
This reverts commit cb96a2c69a.
It is not a mistake to pass args when -b is specified. They will simply
be passed on to the container's init.
The manpage needs fixing, that's true.
systemd-nspawn will now print the PID of the child.
An example showing how to enter the container is added
to the man page.
Support for nsenter without an explicit command was
added in https://github.com/karelzak/util-linux/commit/5758069
(post v2.22.2). So this example requires both a new kernel
and the latest util-linux.
Option listings seemed to be pretty much random, some were short opt,
long opt, others were long opt, short opt. This just makes every option
with a short and long opt that I could find in the order short opt, long
opt, for formatting's sake.
Archlinux has a similar tool to debbotstrap in the arch-install-scripts
package that will install to a specified directory. This is generally
used for installation, so the -d flag must be passed to tell it to
install to a non-mountpoint directory.
Due to the brokeness of much of the userspace audit code we cannot
really start too many systems without the audit caps set. To make nspawn
easier to use just add the audit caps by default.
To boot up containers successfully the kernel's auditing needs to be
turned off still (use "audit=0" on the kernel command line), but at
least no manual caps have to be passed anymore.
In the long run auditing will be fixed for containers and ve virtualized
properly at which time it should be safe to enable these caps anyway.
https://bugs.freedesktop.org/show_bug.cgi?id=55890
Fixed typos, serial comma, and removed "either" as there were more
than two options. Also did an extra rename of "system-shutdown"
to "systemd-shutdown" that was forgotten in commit
8bd3b8620c
We finally got the OK from all contributors with non-trivial commits to
relicense systemd from GPL2+ to LGPL2.1+.
Some udev bits continue to be GPL2+ for now, but we are looking into
relicensing them too, to allow free copy/paste of all code within
systemd.
The bits that used to be MIT continue to be MIT.
The big benefit of the relicensing is that closed source code may now
link against libsystemd-login.so and friends.
Add -u/--user option, which changes the effective and real user and
group id to the new value. The user must exists in the chroot, otherwise
it will fail. Both username and user id are accepted. The user home is
created as well.
It also setup HOME, USER, LOGNAME and SHELL variables .
Instead of the /dev/.run trick we have currently implemented, we decided
to move the early-boot runtime dir to /run.
An existing /var/run directory is bind-mounted to /run. If /var/run is
already a symlink, no action is taken.
An existing /var/lock directory is bind-mounted to /run/lock.
If /var/lock is already a symlink, no action is taken.
To implement the directory vs. symlink logic, we have a:
ConditionPathIsDirectory=
now, which is used in the mount units.
Skipped mount unit in case of symlink:
$ systemctl status var-run.mount
var-run.mount - Runtime Directory
Loaded: loaded (/lib/systemd/system/var-run.mount)
Active: inactive (dead)
start condition failed at Fri, 25 Mar 2011 04:51:41 +0100; 6min ago
Where: /var/run
What: /run
CGroup: name=systemd:/system/var-run.mount
The systemd rpm needs to make sure to add something like:
%pre
mkdir -p -m0755 /run >/dev/null 2>&1 || :
or it needs to be added to filesystem.rpm.
Udev -git already uses /run if that exists, and is writable at bootup.
Otherwise it falls back to the current /dev/.udev.
Dracut and plymouth need to be adopted to switch from /dev/.run to run
too.
Cheers,
Kay
