Merge pull request #16566 from poettering/nspawn-osrelease-fixes

nspawn: os-release reorganization, second try
This commit is contained in:
Yu Watanabe 2020-07-24 13:37:31 +09:00 committed by GitHub
commit e128723dae
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
8 changed files with 75 additions and 42 deletions

2
NEWS
View File

@ -546,7 +546,7 @@ CHANGES WITH 246:
has been extended by a set of environment variables that expose
select fields from the host's os-release file to the container
payload. Similarly, host's os-release files can be mounted into the
container underneath /run/hosts. Together, those mechanisms provide a
container underneath /run/host. Together, those mechanisms provide a
standardized way to expose information about the host to the
container payload. Both interfaces are implemented in systemd-nspawn.

4
TODO
View File

@ -17,6 +17,10 @@ Janitorial Clean-ups:
Features:
* nspawn: move "incoming mount" directory to /run/host, move "inaccessible"
nodes to /run/host, move notify socket (for sd_notify() between payload and
container manager)
* cryptsetup: if keyfile specified in crypttab is AF_UNIX socket, connect to it
and read from it (like we do elsewhere with READ_FULL_FILE_CONNECT_SOCKET)

View File

@ -342,10 +342,9 @@
<para>Container and sandbox runtime managers may make the host's
identification data available to applications by providing the host's
<filename>/etc/os-release</filename> and
<filename>/usr/lib/os-release</filename> as respectively
<filename>/run/host/etc/os-release</filename> and
<filename>/run/host/usr/lib/os-release</filename>.</para>
<filename>/etc/os-release</filename> (if available, otherwise
<filename>/usr/lib/os-release</filename> as a fallback) as
<filename>/run/host/os-release</filename>.</para>
</refsect1>
<refsect1>

View File

@ -1,3 +1,4 @@
/* SPDX-License-Identifier: LGPL-2.1+ */
#pragma once
#include <sys/types.h>

View File

@ -563,15 +563,16 @@ int mount_all(const char *dest,
MOUNT_FATAL|MOUNT_MKDIR },
{ "tmpfs", "/run", "tmpfs", "mode=755" TMPFS_LIMITS_RUN, MS_NOSUID|MS_NODEV|MS_STRICTATIME,
MOUNT_FATAL|MOUNT_MKDIR },
{ "/usr/lib/os-release", "/run/host/usr/lib/os-release", NULL, NULL, MS_BIND,
MOUNT_FATAL|MOUNT_MKDIR|MOUNT_TOUCH }, /* As per kernel interface requirements, bind mount first (creating mount points) and make read-only later */
{ NULL, "/run/host/usr/lib/os-release", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT,
0 },
{ "/etc/os-release", "/run/host/etc/os-release", NULL, NULL, MS_BIND,
MOUNT_MKDIR|MOUNT_TOUCH },
{ NULL, "/run/host/etc/os-release", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT,
0 },
{ "/run/host", "/run/host", NULL, NULL, MS_BIND,
MOUNT_FATAL|MOUNT_MKDIR|MOUNT_PREFIX_ROOT }, /* Prepare this so that we can make it read-only when we are done */
{ "/etc/os-release", "/run/host/os-release", NULL, NULL, MS_BIND,
MOUNT_TOUCH }, /* As per kernel interface requirements, bind mount first (creating mount points) and make read-only later */
{ "/usr/lib/os-release", "/run/host/os-release", NULL, NULL, MS_BIND,
MOUNT_FATAL }, /* If /etc/os-release doesn't exist use the version in /usr/lib as fallback */
{ NULL, "/run/host/os-release", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT,
MOUNT_FATAL },
{ NULL, "/run/host", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT,
MOUNT_FATAL|MOUNT_IN_USERNS },
#if HAVE_SELINUX
{ "/sys/fs/selinux", "/sys/fs/selinux", NULL, NULL, MS_BIND,
MOUNT_MKDIR }, /* Bind mount first (mkdir/chown the mount point in case /sys/ is mounted as minimal skeleton tmpfs) */
@ -589,9 +590,9 @@ int mount_all(const char *dest,
int r;
for (k = 0; k < ELEMENTSOF(mount_table); k++) {
_cleanup_free_ char *where = NULL, *options = NULL;
const char *o;
_cleanup_free_ char *where = NULL, *options = NULL, *prefixed = NULL;
bool fatal = FLAGS_SET(mount_table[k].mount_settings, MOUNT_FATAL);
const char *o;
if (in_userns != FLAGS_SET(mount_table[k].mount_settings, MOUNT_IN_USERNS))
continue;
@ -616,20 +617,9 @@ int mount_all(const char *dest,
return log_error_errno(r, "Failed to detect whether %s is a mount point: %m", where);
if (r > 0)
continue;
/* Shortcut for optional bind mounts: if the source can't be found skip ahead to avoid creating
* empty and unused directories. */
if (!fatal && FLAGS_SET(mount_table[k].mount_settings, MOUNT_MKDIR) && FLAGS_SET(mount_table[k].flags, MS_BIND)) {
r = access(mount_table[k].what, F_OK);
if (r < 0) {
if (errno == ENOENT)
continue;
return log_error_errno(errno, "Failed to stat %s: %m", mount_table[k].what);
}
}
}
if (FLAGS_SET(mount_table[k].mount_settings, MOUNT_MKDIR)) {
if ((mount_table[k].mount_settings & (MOUNT_MKDIR|MOUNT_TOUCH)) != 0) {
uid_t u = (use_userns && !in_userns) ? uid_shift : UID_INVALID;
if (FLAGS_SET(mount_table[k].mount_settings, MOUNT_TOUCH))
@ -647,13 +637,17 @@ int mount_all(const char *dest,
if (r != -EROFS)
continue;
}
if (FLAGS_SET(mount_table[k].mount_settings, MOUNT_TOUCH)) {
r = touch(where);
if (r < 0 && r != -EEXIST) {
if (fatal)
return log_error_errno(r, "Failed to create mount point %s: %m", where);
log_debug_errno(r, "Failed to create mount point %s: %m", where);
}
}
if (FLAGS_SET(mount_table[k].mount_settings, MOUNT_TOUCH)) {
r = touch(where);
if (r < 0 && r != -EEXIST) {
if (fatal && r != -EROFS)
return log_error_errno(r, "Failed to create file %s: %m", where);
log_debug_errno(r, "Failed to create file %s: %m", where);
if (r != -EROFS)
continue;
}
}
@ -666,8 +660,18 @@ int mount_all(const char *dest,
o = options;
}
if (FLAGS_SET(mount_table[k].mount_settings, MOUNT_PREFIX_ROOT)) {
/* Optionally prefix the mount source with the root dir. This is useful in bind
* mounts to be created within the container image before we transition into it. Note
* that MOUNT_IN_USERNS is run after we transitioned hence prefixing is not ncessary
* for those. */
r = chase_symlinks(mount_table[k].what, dest, CHASE_PREFIX_ROOT, &prefixed, NULL);
if (r < 0)
return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, mount_table[k].what);
}
r = mount_verbose(fatal ? LOG_ERR : LOG_DEBUG,
mount_table[k].what,
prefixed ?: mount_table[k].what,
where,
mount_table[k].type,
mount_table[k].flags,

View File

@ -18,6 +18,7 @@ typedef enum MountSettingsMask {
MOUNT_NON_ROOT_ONLY = 1 << 7, /* if set, only non-root mounts are mounted */
MOUNT_MKDIR = 1 << 8, /* if set, make directory to mount over first */
MOUNT_TOUCH = 1 << 9, /* if set, touch file to mount over first */
MOUNT_PREFIX_ROOT = 1 << 10,/* if set, prefix the source path with the container's root directory */
} MountSettingsMask;
typedef enum CustomMountType {

View File

@ -695,17 +695,28 @@ static int install_chroot_dropin(
if (!text)
return -ENOMEM;
if (endswith(m->name, ".service"))
if (endswith(m->name, ".service")) {
const char *os_release_source;
if (access("/etc/os-release", F_OK) < 0) {
if (errno != ENOENT)
return log_debug_errno(errno, "Failed to check if /etc/os-release exists: %m");
os_release_source = "/usr/lib/os-release";
} else
os_release_source = "/etc/os-release";
if (!strextend(&text,
"\n"
"[Service]\n",
IN_SET(type, IMAGE_DIRECTORY, IMAGE_SUBVOLUME) ? "RootDirectory=" : "RootImage=", image_path, "\n"
"Environment=PORTABLE=", basename(image_path), "\n"
"BindReadOnlyPaths=-/etc/os-release:/run/host/etc/os-release /usr/lib/os-release:/run/host/usr/lib/os-release\n"
"BindReadOnlyPaths=", os_release_source, ":/run/host/os-release\n"
"LogExtraFields=PORTABLE=", basename(image_path), "\n",
NULL))
return -ENOMEM;
}
r = write_string_file(dropin, text, WRITE_STRING_FILE_CREATE|WRITE_STRING_FILE_ATOMIC);
if (r < 0)

View File

@ -66,12 +66,25 @@ if [ -n "${ID:+set}" ] && [ "${ID}" != "${container_host_id}" ]; then exit 1; fi
if [ -n "${VERSION_ID:+set}" ] && [ "${VERSION_ID}" != "${container_host_version_id}" ]; then exit 1; fi
if [ -n "${BUILD_ID:+set}" ] && [ "${BUILD_ID}" != "${container_host_build_id}" ]; then exit 1; fi
if [ -n "${VARIANT_ID:+set}" ] && [ "${VARIANT_ID}" != "${container_host_variant_id}" ]; then exit 1; fi
cd /tmp; (cd /run/host/usr/lib; md5sum os-release) | md5sum -c
if echo test >> /run/host/usr/lib/os-release; then exit 1; fi
if echo test >> /run/host/etc/os-release; then exit 1; fi
cd /tmp; (cd /run/host; md5sum os-release) | md5sum -c
if echo test >> /run/host/os-release; then exit 1; fi
'
systemd-nspawn --register=no -D /testsuite-13.nc-container --bind=/etc/os-release:/tmp/os-release /bin/sh -x -e -c "$_cmd"
local _os_release_source="/etc/os-release"
if [ ! -r "${_os_release_source}" ]; then
_os_release_source="/usr/lib/os-release"
elif [ -L "${_os_release_source}" ] && rm /etc/os-release; then
# Ensure that /etc always wins if available
cp /usr/lib/os-release /etc
echo MARKER=1 >> /etc/os-release
fi
systemd-nspawn --register=no -D /testsuite-13.nc-container --bind="${_os_release_source}":/tmp/os-release /bin/sh -x -e -c "$_cmd"
if grep -q MARKER /etc/os-release; then
rm /etc/os-release
ln -s ../usr/lib/os-release /etc/os-release
fi
}
function run {