diff options
| author | Philip Withnall <philip@tecnocode.co.uk> | 2017-02-08 15:54:31 +0000 |
|---|---|---|
| committer | Lennart Poettering <lennart@poettering.net> | 2017-02-08 16:54:31 +0100 |
| commit | b53ede699cdc5233041a22591f18863fb3fe2672 (patch) | |
| tree | 728b42c4061e2319671a7596128e6ba51ac9f083 /man | |
| parent | 6a909d41e1835a77ff65fe93002245faaaf6047a (diff) | |
nspawn: Add support for sysroot pivoting (#5258)
Add a new --pivot-root argument to systemd-nspawn, which specifies a
directory to pivot to / inside the container; while the original / is
pivoted to another specified directory (if provided). This adds
support for booting container images which may contain several bootable
sysroots, as is common with OSTree disk images. When these disk images
are booted on real hardware, ostree-prepare-root is run in conjunction
with sysroot.mount in the initramfs to achieve the same results.
Diffstat (limited to 'man')
| -rw-r--r-- | man/systemd-nspawn.xml | 21 | ||||
| -rw-r--r-- | man/systemd.nspawn.xml | 9 |
2 files changed, 30 insertions, 0 deletions
diff --git a/man/systemd-nspawn.xml b/man/systemd-nspawn.xml index f6b3f57fc7..5e671d21e8 100644 --- a/man/systemd-nspawn.xml +++ b/man/systemd-nspawn.xml @@ -336,6 +336,21 @@ </varlistentry> <varlistentry> + <term><option>--pivot-root=</option></term> + + <listitem><para>Pivot the specified directory to <filename>/</filename> inside the container, and either unmount the + container's old root, or pivot it to another specified directory. Takes one of: a path argument — in which case the + specified path will be pivoted to <filename>/</filename> and the old root will be unmounted; or a colon-separated pair + of new root path and pivot destination for the old root. The new root path will be pivoted to <filename>/</filename>, + and the old <filename>/</filename> will be pivoted to the other directory. Both paths must be absolute, and are resolved + in the container's file system namespace.</para> + + <para>This is for containers which have several bootable directories in them; for example, several + <ulink url="https://ostree.readthedocs.io/en/latest/">OSTree</ulink> deployments. It emulates the behavior of the boot + loader and initial RAM disk which normally select which directory to mount as root and start the container's PID 1 in.</para></listitem> + </varlistentry> + + <varlistentry> <term><option>-u</option></term> <term><option>--user=</option></term> @@ -1082,6 +1097,12 @@ <programlisting># 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</programlisting> </example> + + <example> + <title>Run a container with an OSTree deployment</title> + + <programlisting># systemd-nspawn -b -i ~/image.raw --pivot-root=/ostree/deploy/$OS/deploy/$CHECKSUM:/sysroot --bind=+/sysroot/ostree/deploy/$OS/var:/var</programlisting> + </example> </refsect1> <refsect1> diff --git a/man/systemd.nspawn.xml b/man/systemd.nspawn.xml index 7143188356..4f3f052911 100644 --- a/man/systemd.nspawn.xml +++ b/man/systemd.nspawn.xml @@ -202,6 +202,15 @@ </varlistentry> <varlistentry> + <term><varname>PivotRoot=</varname></term> + + <listitem><para>Selects a directory to pivot to <filename>/</filename> inside the container when starting up. + Takes a single path, or a pair of two paths separated by a colon. Both paths must be absolute, and are resolved + in the container's file system namespace. This corresponds to the <option>--pivot-root=</option> command line + switch.</para></listitem> + </varlistentry> + + <varlistentry> <term><varname>Capability=</varname></term> <term><varname>DropCapability=</varname></term> |