The code in prepareRoot (e385f67a0e/libcontainer/rootfs_linux.go (L599-L605))
attempts to default the rootfs mount to `rslave`. However, since the spec
conversion has already defaulted it to `rprivate`, that code doesn't
actually ever do anything.
This changes the spec conversion code to accept "" and treat it as 0.
Implicitly, this makes rootfs propagation default to `rslave`, which is
a part of fixing the moby bug https://github.com/moby/moby/issues/34672
Alternate implementatoins include changing this defaulting to be
`rslave` and removing the defaulting code in prepareRoot, or skipping
the mapping entirely for "", but I think this change is the cleanest of
those options.
Signed-off-by: Euan Kemp <euan.kemp@coreos.com>
In current implementation:
Either Intel RDT is not enabled by hardware and kernel, or intelRdt is
not specified in original config, we don't init IntelRdtManager in the
container to handle intelrdt constraint. It is a tradeoff that Intel RDT
has hardware limitation to support only limited number of groups.
This patch makes a minor change to support update command:
Whether or not intelRdt is specified in config, we always init
IntelRdtManager in the container if Intel RDT is enabled. If intelRdt is
not specified in original config, we just don't Apply() to create
intelrdt group or attach tasks for this container.
In update command, we could re-enable through IntelRdtManager.Apply()
and then update intelrdt constraint.
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
This fix tries to address the warnings caused by static build
with go 1.9. As systemd needs dlopen/dlclose, the following warnings
will be generated for static build in go 1.9:
```
root@f4b077232050:/go/src/github.com/opencontainers/runc# make static
CGO_ENABLED=1 go build -tags "seccomp cgo static_build" -ldflags "-w -extldflags -static -X main.gitCommit="1c81e2a794c6e26a4c650142ae8893c47f619764" -X main.version=1.0.0-rc4+dev " -o runc .
/tmp/go-link-113476657/000007.o: In function `_cgo_a5acef59ed3f_Cfunc_dlopen':
/tmp/go-build/github.com/opencontainers/runc/vendor/github.com/coreos/pkg/dlopen/_obj/cgo-gcc-prolog:76: warning: Using 'dlopen' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
```
This fix disables systemd when `static_build` flag is on (apply_nosystemd.go
is used instead).
This fix also fixes a small bug in `apply_nosystemd.go` for return value.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
This fix adds `netgo` to tags for static build so that
the following warning could be addressed:
```
/tmp/go-link-355596637/000000.o: In function `_cgo_b0c710f30cfd_C2func_getaddrinfo':
/tmp/go-build/net/_obj/cgo-gcc-prolog:46: warning: Using 'getaddrinfo' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
```
The above warning appears when building `make static` with
go 1.9.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
Enable several previously disabled tests (for the idmap execution mode)
for rootless containers, in addition to making all tests use the
additional mappings. At the moment there's no strong need to add any
additional tests purely for rootless_idmap.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
This is necessary in order to add proper opportunistic tests, and is a
placeholder until we add tests for new{uid,gid}map configurations.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Now that rootless containers have support for multiple uid and gid
mappings, allow --user to work as expected. If the user is not mapped,
an error occurs (as usual).
Signed-off-by: Aleksa Sarai <asarai@suse.de>
With the addition of our new{uid,gid}map support, we used to call
execvp(3) from inside nsexec. This would mean that the path resolution
for the binaries would happen in nsexec. Move the resolution to the
initial setup code, and pass the absolute path to nsexec.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
After quite a bit of debugging, I found that previous versions of this
patchset did not include newgidmap in a rootless setting. Fix this by
passing it whenever group mappings are applied, and also providing some
better checking for try_mapping_tool. This commit also includes some
stylistic improvements.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Take advantage of the newuidmap/newgidmap tools to allow multiple
users/groups to be mapped into the new user namespace in the rootless
case.
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
[ rebased to handle intelrdt changes. ]
Signed-off-by: Aleksa Sarai <asarai@suse.de>
This is the follow-up PR of #1279 to fix remaining issues:
Use init() to avoid race condition in IsIntelRdtEnabled().
Add also rename some variables and functions.
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
This applies cgroups earlier for container creation before the init
process starts running and forking off any additional processes.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
The lazy-pages test case is not as straight forward as the other test
cases. This is related to the fact that restoring requires a different
name if restored on the same host. During 'runc checkpoint' the
container is not destroyed before all memory pages have been transferred
to the destination and thus the same container name cannot be used.
As real world usage will rather migrate a container from one system to
another than lazy migrate a container on the same host this is only
problematic for this test case.
Another reason is that it requires starting 'runc checkpoint' and 'criu
lazy-pages' in the background as those process need to be running to
start the final restore 'runc restore'.
CRIU upstream is currently discussing to automatically start 'criu
lazy-pages' which would simplify the lazy-pages test case a bit.
The handling and checking of the background processes make the test case
not the most elegant as at one point a 'sleep 2' is required to make
sure that 'runc checkpoint' had time to do its thing before looking at
log files.
Before running the actual test criu is called in feature checking mode
to make sure lazy migration is in the test case criu enabled. If not,
the test is skipped.
Signed-off-by: Adrian Reber <areber@redhat.com>
With the help of userfaultfd CRIU supports lazy migration. Lazy
migration means that memory pages are only transferred from the
migration source to the migration destination on page fault.
This enables to reduce the downtime during process or container
migration to a minimum as the memory does not need to be transferred
during migration.
Lazy migration currently depends on userfaultfd being available on the
current Linux kernel and if the used CRIU version supports lazy
migration. Both dependencies can be checked by querying CRIU via RPC if
the lazy migration feature is available. Using feature checking instead
of version comparison enables runC to use CRIU features from the
criu-dev branch. This way the user can decide if lazy migration should
be available by choosing the right kernel and CRIU branch.
To use lazy migration the CRIU process during dump needs to dump
everything besides the memory pages and then it opens a network port
waiting for remote page fault requests:
# runc checkpoint httpd --lazy-pages --page-server 0.0.0.0:27 \
--status-fd /tmp/postcopy-pipe
In this example CRIU will hang/wait once it has opened the network port
and wait for network connection. As runC waits for CRIU to finish it
will also hang until the lazy migration has finished. To know when the
restore on the destination side can start the '--status-fd' parameter is
used:
#️ runc checkpoint --help | grep status
--status-fd value criu writes \0 to this FD once lazy-pages is ready
The parameter '--status-fd' is directly from CRIU and this way the
process outside of runC which controls the migration knows exactly when
to transfer the checkpoint (without memory pages) to the destination and
that the restore can be started.
On the destination side it is necessary to start CRIU in 'lazy-pages'
mode like this:
# criu lazy-pages --page-server --address 192.168.122.3 --port 27 \
-D checkpoint
and tell runC to do a lazy restore:
# runc restore -d --image-path checkpoint --work-path checkpoint \
--lazy-pages httpd
If both processes on the restore side have the same working directory
'criu lazy-pages' creates a unix domain socket where it waits for
requests from the actual restore. runC starts CRIU restore in lazy
restore mode and talks to 'criu lazy-pages' that it wants to restore
memory pages on demand. CRIU continues to restore the process and once
the process is running and accesses the first non-existing memory page
the 'criu lazy-pages' server will request the page from the source
system. Thus all pages from the source system will be transferred to the
destination system. Once all pages have been transferred runC on the
source system will end and the container will have finished migration.
This can also be combined with CRIU's pre-copy support. The combination
of pre-copy and post-copy (lazy migration) provides the possibility to
migrate containers with minimal downtimes.
Some additional background about post-copy migration can be found in
these articles:
https://lisas.de/~adrian/?p=1253https://lisas.de/~adrian/?p=1183
Signed-off-by: Adrian Reber <areber@redhat.com>
Before adding the actual lazy migration support, this adds the feature
check for lazy-pages. Right now lazy migration, which is based on
userfaultd is only available in the criu-dev branch and not yet in a
release. As the check does not dependent on a certain version but on
a CRIU feature which can be queried it can be part of runC without a new
version check depending on a feature from criu-dev.
Signed-off-by: Adrian Reber <areber@redhat.com>
About Intel RDT/CAT feature:
Intel platforms with new Xeon CPU support Intel Resource Director Technology
(RDT). Cache Allocation Technology (CAT) is a sub-feature of RDT, which
currently supports L3 cache resource allocation.
This feature provides a way for the software to restrict cache allocation to a
defined 'subset' of L3 cache which may be overlapping with other 'subsets'.
The different subsets are identified by class of service (CLOS) and each CLOS
has a capacity bitmask (CBM).
For more information about Intel RDT/CAT can be found in the section 17.17
of Intel Software Developer Manual.
About Intel RDT/CAT kernel interface:
In Linux 4.10 kernel or newer, the interface is defined and exposed via
"resource control" filesystem, which is a "cgroup-like" interface.
Comparing with cgroups, it has similar process management lifecycle and
interfaces in a container. But unlike cgroups' hierarchy, it has single level
filesystem layout.
Intel RDT "resource control" filesystem hierarchy:
mount -t resctrl resctrl /sys/fs/resctrl
tree /sys/fs/resctrl
/sys/fs/resctrl/
|-- info
| |-- L3
| |-- cbm_mask
| |-- min_cbm_bits
| |-- num_closids
|-- cpus
|-- schemata
|-- tasks
|-- <container_id>
|-- cpus
|-- schemata
|-- tasks
For runc, we can make use of `tasks` and `schemata` configuration for L3 cache
resource constraints.
The file `tasks` has a list of tasks that belongs to this group (e.g.,
<container_id>" group). Tasks can be added to a group by writing the task ID
to the "tasks" file (which will automatically remove them from the previous
group to which they belonged). New tasks created by fork(2) and clone(2) are
added to the same group as their parent. If a pid is not in any sub group, it
Is in root group.
The file `schemata` has allocation bitmasks/values for L3 cache on each socket,
which contains L3 cache id and capacity bitmask (CBM).
Format: "L3:<cache_id0>=<cbm0>;<cache_id1>=<cbm1>;..."
For example, on a two-socket machine, L3's schema line could be `L3:0=ff;1=c0`
which means L3 cache id 0's CBM is 0xff, and L3 cache id 1's CBM is 0xc0.
The valid L3 cache CBM is a *contiguous bits set* and number of bits that can
be set is less than the max bit. The max bits in the CBM is varied among
supported Intel Xeon platforms. In Intel RDT "resource control" filesystem
layout, the CBM in a group should be a subset of the CBM in root. Kernel will
check if it is valid when writing. e.g., 0xfffff in root indicates the max bits
of CBM is 20 bits, which mapping to entire L3 cache capacity. Some valid CBM
values to set in a group: 0xf, 0xf0, 0x3ff, 0x1f00 and etc.
For more information about Intel RDT/CAT kernel interface:
https://www.kernel.org/doc/Documentation/x86/intel_rdt_ui.txt
An example for runc:
Consider a two-socket machine with two L3 caches where the default CBM is
0xfffff and the max CBM length is 20 bits. With this configuration, tasks
inside the container only have access to the "upper" 80% of L3 cache id 0 and
the "lower" 50% L3 cache id 1:
"linux": {
"intelRdt": {
"l3CacheSchema": "L3:0=ffff0;1=3ff"
}
}
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
It looks like we missed this in 5930d5b427 ("Remove shfmt"), which was
causing CI to break (since it looks like the repo has moved or something
like that). Since we're no longer using shfmt, drop it completely from
the repo.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Fixes a race that occurred very frequently in testing where the tty of
the container may be closed by the time that runc gets to sending
SIGWINCH. This failure mode is not fatal, but it would cause test
failures due to expected outputs not matching. On further review it
appears that the original addition of these checks in 4c5bf649d0
("Check error return values") was actually not necessary, so partially
revert that change.
The particular failure mode this resolves would manifest as error logs
of the form:
time="2017-08-24T07:59:50Z" level=error msg="bad file descriptor"
Fixes: 4c5bf649d0 ("Check error return values")
Signed-off-by: Aleksa Sarai <asarai@suse.de>
This mirrors the standard_init_linux.go seccomp code, which only applies
seccomp early if NoNewPrivileges is enabled. Otherwise it's done
immediately before execve to reduce the amount of syscalls necessary for
users to enable in their seccomp profiles.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Tobias Klauser
Qiang Huang
Euan Kemp
Michael Crosby
leitwolf7
s7v7nislands
Xiaochen Shen
Aleksa Sarai
Yong Tang
Mrunal Patel
Giuseppe Scrivano
Ma Shimiao
Adrian Reber