The default value was described at the end of two long paragraphs.
Make the first para self contained, and move the description of --console=pipe
into the second para.
To access a shell on a disk image, the man page on Fedora-29 says to
run: `systemd-nspawn -M Fedora-Cloud-Base-28-1.1.x86_64.raw`. Let's
try.
List existing images:
$> machinectl list-images | awk '{print $1,$2}';
NAME TYPE
Fedora-Cloud-Base-30… raw
1 images
Now invoke `systemd-nspawn` as noted in the man page:
$> systemd-nspawn -M Fedora-Cloud-Base-30-1.2.x86_64.raw
No image for machine 'Fedora-Cloud-Base-30-1.2.x86_64.raw'.
Removing the ".raw" extension launches the image and gives a shell.
Update the man page to reflect that.
Frantisek Sumsal on #systemd (Freenode) noted the reason: "In older
versions systemd -M accepted both image-name.raw and image-name as a
valid image names, however, on Fedora 29 (systemd-239) with all the
BTRFS stuff around it accepts only -M image-name (without the
extension)"
- - -
While at it, update the fedora_{latest_version, cloud_release}
variables.
Signed-off-by: Kashyap Chamarthy <kchamart@redhat.com>
No other changes, just some reshuffling and adding of section headers
(well, admittedly, I changed some "see above" and "see below" in the
text to match the new order.)
The "include" files had type "book" for some raeason. I don't think this
is meaningful. Let's just use the same everywhere.
$ perl -i -0pe 's^..DOCTYPE (book|refentry) PUBLIC "-//OASIS//DTD DocBook XML V4.[25]//EN"\s+"http^<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"\n "http^gms' man/*.xml
No need to waste space, and uniformity is good.
$ perl -i -0pe 's|\n+<!--\s*SPDX-License-Identifier: LGPL-2.1..\s*-->|\n<!-- SPDX-License-Identifier: LGPL-2.1+ -->|gms' man/*.xml
nspawn as it is now is a generally useful tool, hence let's drop the
comments about it being useful for debug and so on only.
The new wording just makes the first sentence of the main page also the
summary.
Docbook styles required those to be present, even though the templates that we
use did not show those names anywhere. But something changed semi-recently (I
would suspect docbook templates, but there was only a minor version bump in
recent years, and the changelog does not suggest anything related), and builds
now work without those entries. Let's drop this dead weight.
Tested with F26-F29, debian unstable.
$ perl -i -0pe 's/\s*<authorgroup>.*<.authorgroup>//gms' man/*xml
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Fedora 28 is out already, let's advertise it. While at it, drop "container"
from "f28container" — it's a subdirectory under /var/lib/machines, it's pretty
obvious that's it a container.
To make the switch easier in the future, define the number as an entity.
Similar as the other options added before, this is primarily useful to
provide comprehensive OCI runtime compatbility, but might be useful
otherwise, too.
This simply controls the PR_SET_NO_NEW_PRIVS flag for the container.
This too is primarily relevant to provide OCI runtime compaitiblity, but
might have other uses too, in particular as it nicely complements the
existing --capability= and --drop-capability= flags.
Previously, the container's hostname was exclusively initialized from
the machine name configured with --machine=, i.e. the internal name and
the external name used for and by the container was synchronized. This
adds a new option --hostname= that optionally allows the internal name
to deviate from the external name.
This new option is mainly useful to ultimately implement the OCI runtime
spec directly in nspawn, but it might be useful on its own for some
other usecases too.
This ensures we set the various resource limits of our container
explicitly on each invocation so that we inherit less from our callers
into the payload.
By default resource limits are now set to the same values Linux
generally passes to the host PID 1, thus minimizing needless differences
between host and container environments.
The limits are now also configurable using a new --rlimit= switch. This
is preparation for teaching nspawn native OCI runtime support as OCI
permits setting resource limits for container payloads, and it hence
probably makes sense if we do too.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
Nowadays people use systemd on many different architectures, so we
shouldn't presuppose that they are using amd64. debootstrap defaults
to the native architecture and this should be good enough.
Systemd services are permitted to be scripts, as well as binary
executables.
The same also applies to the underlying /sbin/mount and /sbin/swapon.
It is not necessary for the user to consider what type of program file
these are. Nor is it necessary with systemd-nspawn, to distinguish between
init as a "binary" v.s. a user-specified "program".
Also fix a couple of grammar nits in the modified sentences.
Add a new option `--network-namespace-path` to systemd-nspawn to allow
users to specify an arbitrary network namespace, e.g. `/run/netns/foo`.
Then systemd-nspawn will open the netns file, pass the fd to
outer_child, and enter the namespace represented by the fd before
running inner_child.
```
$ sudo ip netns add foo
$ mount | grep /run/netns/foo
nsfs on /run/netns/foo type nsfs (rw)
...
$ sudo systemd-nspawn -D /srv/fc27 --network-namespace-path=/run/netns/foo \
/bin/readlink -f /proc/self/ns/net
/proc/1/ns/net:[4026532009]
```
Note that the option `--network-namespace-path=` cannot be used together
with other network-related options such as `--private-network` so that
the options do not conflict with each other.
Fixes https://github.com/systemd/systemd/issues/7361
Let's lock things down a bit, and maintain a list of what's permitted
rather than a list of what's prohibited in nspawn (also to make things a
bit more like Docker and friends).
Note that this slightly alters the effect of --system-call-filter=, as
now the negative list now takes precedence over the positive list.
However, given that the option is just a few days old and not included
in any released version it should be fine to change it at this point in
time.
Note that the whitelist is good chunk more restrictive thatn the
previous blacklist. Specifically:
- fanotify is not permitted (given the buffer size issues it's
problematic in containers)
- nfsservctl is not permitted (NFS server support is not virtualized)
- pkey_xyz stuff is not permitted (really new stuff I don't grok)
- @cpu-emulation is prohibited (untested legacy stuff mostly, and if
people really want to run dosemu in nspawn, they should use
--system-call-filter=@cpu-emulation and all should be good)
Now that we have ported nspawn's seccomp code to the generic code in
seccomp-util, let's extend it to support whitelisting and blacklisting
of specific additional syscalls.
This uses similar syntax as PID1's support for system call filtering,
but in contrast to that always implements a blacklist (and not a
whitelist), as we prepopulate the filter with a blacklist, and the
unit's system call filter logic does not come with anything
prepopulated.
(Later on we might actually want to invert the logic here, and
whitelist rather than blacklist things, but at this point let's not do
that. In case we switch this over later, the syscall add/remove logic of
this commit should be compatible conceptually.)
Fixes: #5163
Replaces: #5944
Previously, only when --register=yes was set (the default) the invoked
container would get its own scope, created by machined on behalf of
nspawn. With this change if --register=no is set nspawn will still get
its own scope (which is a good thing, so that --slice= and --property=
take effect), but this is not done through machined but by registering a
scope unit directly in PID 1.
Summary:
--register=yes → allocate a new scope through machined (the default)
--register=yes --keep-unit → use the unit we are already running in an register with machined
--register=no → allocate a new scope directly, but no machined
--register=no --keep-unit → do not allocate nor register anything
Fixes: #5823
