`VolumeOptions` now has a `Subpath` field which allows to specify a path
relative to the volume that should be mounted as a destination.
Symlinks are supported, but they cannot escape the base volume
directory.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
Split task creation and start into two separate method calls in the
libcontainerd API. Clients now have the opportunity to inspect the
freshly-created task and customize its runtime environment before
starting execution of the user-specified binary.
Signed-off-by: Cory Snider <csnider@mirantis.com>
The `ContainerCreateConfig` and `ContainerRmConfig` structs are used for
options to be passed to the backend, and are not used in client code.
Thess struct currently is intended for internal use only (for example, the
`AdjustCPUShares` is an internal implementation details to adjust the container's
config when older API versions are used).
Somewhat ironically, the signature of the Backend has a nicer UX than that
of the client's `ContainerCreate` signature (which expects all options to
be passed as separate arguments), so we may want to update that signature
to be closer to what the backend is using, but that can be left as a future
exercise.
This patch moves the `ContainerCreateConfig` and `ContainerRmConfig` structs
to the backend package to prevent it being imported in the client, and to make
it more clear that this is part of internal APIs, and not public-facing.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
The github.com/containerd/containerd/log package was moved to a separate
module, which will also be used by upcoming (patch) releases of containerd.
This patch moves our own uses of the package to use the new module.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Define consts for the Actions we use for events, instead of "ad-hoc" strings.
Having these consts makes it easier to find where specific events are triggered,
makes the events less error-prone, and allows documenting each Action (if needed).
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Removing this type, because:
- containerNotModifiedError is not an actual error, and abstracting it away
was hiding some of these details. It also wasn't used as a sentinel error
anywhere, so doesn't have to be its own type.
- Defining a type just to toggle the error-message between "not running"
and "not stopped" felt a bit over-the-top, as each variant was only used once.
- So "it only had one job", and it didn't even do that right; it produced
capitalized error messages, which makes linters unhappy.
So, let's just inline what it does in the two places it was used.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
There's no need for this to be a closure; let's just make it a regular
function. While moving it out, also make some minor code-changes and
add some code-comments to describe the flow / intent, which may not
be trivial for people that are not familiar with these details.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Any error that occurs while creating the spec, even if it's the
result of an invalid container config, must be considered a System
error (internal server error), as it's not an error with the request
to start the container.
Invalid configuration in the config itself must be validated when
creating the container (creating its config), but some errors are
dependent on the current state, for example when starting a container
that shares a namespace with another container, and that container
is not running (or missing).
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Some snapshotters (like overlayfs or zfs) can't mount the same
directories twice. For example if the same directroy is used as an upper
directory in two mounts the kernel will output this warning:
overlayfs: upperdir is in-use as upperdir/workdir of another mount, accessing files from both mounts will result in undefined behavior.
And indeed accessing the files from both mounts will result in an "No
such file or directory" error.
This change introduces reference counts for the mounts, if a directory
is already mounted the mount interface will only increment the mount
counter and return the mount target effectively making sure that the
filesystem doesn't end up in an undefined behavior.
Signed-off-by: Djordje Lukic <djordje.lukic@docker.com>
The existing runtimes reload logic went to great lengths to replace the
directory containing runtime wrapper scripts as atomically as possible
within the limitations of the Linux filesystem ABI. Trouble is,
atomically swapping the wrapper scripts directory solves the wrong
problem! The runtime configuration is "locked in" when a container is
started, including the path to the runC binary. If a container is
started with a runtime which requires a daemon-managed wrapper script
and then the daemon is reloaded with a config which no longer requires
the wrapper script (i.e. some args -> no args, or the runtime is dropped
from the config), that container would become unmanageable. Any attempts
to stop, exec or otherwise perform lifecycle management operations on
the container are likely to fail due to the wrapper script no longer
existing at its original path.
Atomically swapping the wrapper scripts is also incompatible with the
read-copy-update paradigm for reloading configuration. A handler in the
daemon could retain a reference to the pre-reload configuration for an
indeterminate amount of time after the daemon configuration has been
reloaded and updated. It is possible for the daemon to attempt to start
a container using a deleted wrapper script if a request to run a
container races a reload.
Solve the problem of deleting referenced wrapper scripts by ensuring
that all wrapper scripts are *immutable* for the lifetime of the daemon
process. Any given runtime wrapper script must always exist with the
same contents, no matter how many times the daemon config is reloaded,
or what changes are made to the config. This is accomplished by using
everyone's favourite design pattern: content-addressable storage. Each
wrapper script file name is suffixed with the SHA-256 digest of its
contents to (probabilistically) guarantee immutability without needing
any concurrency control. Stale runtime wrapper scripts are only cleaned
up on the next daemon restart.
Split the derived runtimes configuration from the user-supplied
configuration to have a place to store derived state without mutating
the user-supplied configuration or exposing daemon internals in API
struct types. Hold the derived state and the user-supplied configuration
in a single struct value so that they can be updated as an atomic unit.
Signed-off-by: Cory Snider <csnider@mirantis.com>
Ensure data-race-free access to the daemon configuration without
locking by mutating a deep copy of the config and atomically storing
a pointer to the copy into the daemon-wide configStore value. Any
operations which need to read from the daemon config must capture the
configStore value only once and pass it around to guarantee a consistent
view of the config.
Signed-off-by: Cory Snider <csnider@mirantis.com>
Signed-off-by: Djordje Lukic <djordje.lukic@docker.com>
c8d/daemon: Mount root and fill BaseFS
This fixes things that were broken due to nil BaseFS like `docker cp`
and running a container with workdir override.
This is more of a temporary hack than a real solution.
The correct fix would be to refactor the code to make BaseFS and LayerRW
an implementation detail of the old image store implementation and use
the temporary mounts for the c8d implementation instead.
That requires more work though.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
daemon/images: Don't unset BaseFS
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
Rename the variable make it more visible where it's used, as there's were
other "err" variables masking it.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(*Container).CheckpointTo() upserts a snapshot of the container to the
daemon's in-memory ViewDB and also persists the snapshot to disk. It
does not register the live container object with the daemon's container
store, however. The ViewDB and container store are used as the source of
truth for different operations, so having a container registered in one
but not the other can result in inconsistencies. In particular, the List
Containers API uses the ViewDB as its source of truth and the Container
Inspect API uses the container store.
The (*Daemon).setHostConfig() method is called fairly early in the
process of creating a container, long before the container is registered
in the daemon's container store. Due to a rogue CheckpointTo() call
inside setHostConfig(), there is a window of time where a container can
be included in a List Containers API response but "not exist" according
to the Container Inspect API and similar endpoints which operate on a
particular container. Remove the rogue call so that the caller has full
control over when the container is checkpointed and update callers to
checkpoint explicitly. No changes to (*Daemon).create() are needed as it
checkpoints the fully-created container via (*Daemon).Register().
Fixes#44512.
Signed-off-by: Cory Snider <csnider@mirantis.com>
The existing logic to handle container ID conflicts when attempting to
create a plugin container is not nearly as robust as the implementation
in daemon for user containers. Extract and refine the logic from daemon
and use it in the plugin executor.
Signed-off-by: Cory Snider <csnider@mirantis.com>
The containerd client is very chatty at the best of times. Because the
libcontained API is stateless and references containers and processes by
string ID for every method call, the implementation is essentially
forced to use the containerd client in a way which amplifies the number
of redundant RPCs invoked to perform any operation. The libcontainerd
remote implementation has to reload the containerd container, task
and/or process metadata for nearly every operation. This in turn
amplifies the number of context switches between dockerd and containerd
to perform any container operation or handle a containerd event,
increasing the load on the system which could otherwise be allocated to
workloads.
Overhaul the libcontainerd interface to reduce the impedance mismatch
with the containerd client so that the containerd client can be used
more efficiently. Split the API out into container, task and process
interfaces which the consumer is expected to retain so that
libcontainerd can retain state---especially the analogous containerd
client objects---without having to manage any state-store inside the
libcontainerd client.
Signed-off-by: Cory Snider <csnider@mirantis.com>
This caused a race condition where AutoRemove could be restored before
container was considered for restart and made autoremove containers
impossible to restart.
```
$ make DOCKER_GRAPHDRIVER=vfs BIND_DIR=. TEST_FILTER='TestContainerWithAutoRemoveCanBeRestarted' TESTFLAGS='-test.count 1' test-integration
...
=== RUN TestContainerWithAutoRemoveCanBeRestarted
=== RUN TestContainerWithAutoRemoveCanBeRestarted/kill
=== RUN TestContainerWithAutoRemoveCanBeRestarted/stop
--- PASS: TestContainerWithAutoRemoveCanBeRestarted (1.61s)
--- PASS: TestContainerWithAutoRemoveCanBeRestarted/kill (0.70s)
--- PASS: TestContainerWithAutoRemoveCanBeRestarted/stop (0.86s)
PASS
DONE 3 tests in 3.062s
```
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
This changes mounts.NewParser() to create a parser for the current operatingsystem,
instead of one specific to a (possibly non-matching, in case of LCOW) OS.
With the OS-specific handling being removed, the "OS" parameter is also removed
from `daemon.verifyContainerSettings()`, and various other container-related
functions.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
We aren't using containerd's image store, so we shouldn't be setting
this value.
This fixes container checkpoints, where containerd attempts to
checkpoint the image since one is set, but the image does not exist in
containerd.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
In dockerd we already have a concept of a "runtime", which specifies the
OCI runtime to use (e.g. runc).
This PR extends that config to add containerd shim configuration.
This option is only exposed within the daemon itself (cannot be
configured in daemon.json).
This is due to issues in supporting unknown shims which will require
more design work.
What this change allows us to do is keep all the runtime config in one
place.
So the default "runc" runtime will just have it's already existing shim
config codified within the runtime config alone.
I've also added 2 more "stock" runtimes which are basically runc+shimv1
and runc+shimv2.
These new runtime configurations are:
- io.containerd.runtime.v1.linux - runc + v1 shim using the V1 shim API
- io.containerd.runc.v2 - runc + shim v2
These names coincide with the actual names of the containerd shims.
This allows the user to essentially control what shim is going to be
used by either specifying these as a `--runtime` on container create or
by setting `--default-runtime` on the daemon.
For custom/user-specified runtimes, the default shim config (currently
shim v1) is used.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Switch to moby/sys/mount and mountinfo. Keep the pkg/mount for potential
outside users.
This commit was generated by the following bash script:
```
set -e -u -o pipefail
for file in $(git grep -l 'docker/docker/pkg/mount"' | grep -v ^pkg/mount); do
sed -i -e 's#/docker/docker/pkg/mount"#/moby/sys/mount"#' \
-e 's#mount\.\(GetMounts\|Mounted\|Info\|[A-Za-z]*Filter\)#mountinfo.\1#g' \
$file
goimports -w $file
done
```
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
containerd has two objects with regard to containers.
There is a "container" object which is metadata and a "task" which is
manging the actual runtime state.
When docker starts a container, it creartes both the container metadata
and the task at the same time. So when a container exits, docker deletes
both of these objects as well.
This ensures that if, on start, when we go to create the container metadata object
in containerd, if there is an error due to a name conflict that we go
ahead and clean that up and try again.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
As standard mount.Unmount does what we need, let's use it.
In addition, this adds ignoring "not mounted" condition, which
was previously implemented (see PR#33329, commit cfa2591d3f)
via a very expensive call to mount.Mounted().
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Signed-off-by: John Howard <jhoward@microsoft.com>
The re-coalesces the daemon stores which were split as part of the
original LCOW implementation.
This is part of the work discussed in https://github.com/moby/moby/issues/34617,
in particular see the document linked to in that issue.
It's a common scenario for admins and/or monitoring applications to
mount in the daemon root dir into a container. When doing so all mounts
get coppied into the container, often with private references.
This can prevent removal of a container due to the various mounts that
must be configured before a container is started (for example, for
shared /dev/shm, or secrets) being leaked into another namespace,
usually with private references.
This is particularly problematic on older kernels (e.g. RHEL < 7.4)
where a mount may be active in another namespace and attempting to
remove a mountpoint which is active in another namespace fails.
This change moves all container resource mounts into a common directory
so that the directory can be made unbindable.
What this does is prevents sub-mounts of this new directory from leaking
into other namespaces when mounted with `rbind`... which is how all
binds are handled for containers.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Instead of having to create a bunch of custom error types that are doing
nothing but wrapping another error in sub-packages, use a common helper
to create errors of the requested type.
e.g. instead of re-implementing this over and over:
```go
type notFoundError struct {
cause error
}
func(e notFoundError) Error() string {
return e.cause.Error()
}
func(e notFoundError) NotFound() {}
func(e notFoundError) Cause() error {
return e.cause
}
```
Packages can instead just do:
```
errdefs.NotFound(err)
```
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
