The Container.State struct holds the container's state, and most of
its fields are expected to change dynamically. Some o these state-changes
are explicit, for example, setting the container to be "stopped". Other
state changes can be more explicit, for example due to the containers'
process exiting or being "OOM" killed by the kernel.
The distinction between explicit ("desired") state changes and "state"
("actual state") is sometimes vague; for some properties, we clearly
separated them, for example if a user requested the container to be
stopped or restarted, we store state in the Container object itself;
HasBeenManuallyStopped bool // used for unless-stopped restart policy
HasBeenManuallyRestarted bool `json:"-"` // used to distinguish restart caused by restart policy from the manual one
Other properties are more ambiguous. such as "HasBeenStartedBefore" and
"RestartCount", which are stored on the Container (and persisted to
disk), but may be more related to "actual" state, and likely should
not be persisted;
RestartCount int
HasBeenStartedBefore bool
Given that (per the above) concurrency must be taken into account, most
changes to the `container.State` struct should be protected; here's where
things get blurry. While the `State` type provides various accessor methods,
only some of them take concurrency into account; for example, [State.IsRunning]
and [State.GetPID] acquire a lock, whereas [State.ExitCodeValue] does not.
Even the (commonly used) [State.StateString] has no locking at all.
The way to handle this is error-prone; [container.State] contains a mutex,
and it's exported. Given that its embedded in the [container.Container]
struct, it's also exposed as an exported mutex for the container. The
assumption here is that by "merging" the two, the caller to acquire a lock
when either the container _or_ its state must be mutated. However, because
some methods on `container.State` handle their own locking, consumers must
be deeply familiar with the internals; if both changes to the `Container`
AND `Container.State` must be made. This gets amplified more as some
(exported!) methods, such as [container.SetRunning] mutate multiple fields,
but don't acquire a lock (so expect the caller to hold one), but their
(also exported) counterpart (e.g. [State.IsRunning]) do.
It should be clear from the above, that this needs some architectural
changes; a clearer separation between "desired" and "actual" state (opening
the potential to update the container's config without manually touching
its `State`), possibly a method to obtain a read-only copy of the current
state (for those querying state), and reviewing which fields belong where
(and should be persisted to disk, or only remain in memory).
This PR preserves the status quo; it makes no structural changes, other
than exposing where we access the container's state. Where previously the
State fields and methods were referred to as "part of the container"
(e.g. `ctr.IsRunning()` or `ctr.Running`), we now explicitly reference
the embedded `State` (`ctr.State.IsRunning`, `ctr.State.Running`).
The exception (for now) is the mutex, which is still referenced through
the embedded struct (`ctr.Lock()` instead of `ctr.State.Lock()`), as this
is (mostly) by design to protect the container, and what's in it (including
its `State`).
[State.IsRunning]: c4afa77157/daemon/container/state.go (L205-L209)
[State.GetPID]: c4afa77157/daemon/container/state.go (L211-L216)
[State.ExitCodeValue]: c4afa77157/daemon/container/state.go (L218-L228)
[State.StateString]: c4afa77157/daemon/container/state.go (L102-L131)
[container.State]: c4afa77157/daemon/container/state.go (L15-L23)
[container.Container]: c4afa77157/daemon/container/container.go (L67-L75)
[container.SetRunning]: c4afa77157/daemon/container/state.go (L230-L277)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
The stringid package is used in many places; while it's trivial
to implement a similar utility, let's just provide it as a utility
package in the client, removing the daemon-specific logic.
For integration tests, I opted to use the implementation in the
client, as those should not ideally not make assumptions about
the daemon implementation.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
When deleting specific platforms from a multi-platform image, there's
potential risk as platform-specific content might be shared across
images/containers.
For now, require `force` parameter to make the user aware.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
This change adds the ability to delete a specific platform from a
multi-platform image.
Previously, image deletion was an all-or-nothing operation - when
deleting a multi-platform image, all platforms would be removed
together. This change allows users to selectively remove individual
platforms from a multi-architecture image while keeping other platforms
intact.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
`imageDeleteConflict` is always returned via a reference, so adjust the
method receiver of `Conflict` to make it consistent with `Error`.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
daemon/containerd/image_delete.go:378:4: shadow: declaration of "img" shadows declaration at line 355 (govet)
img := images.Image{
^
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
This internal package was added in f6e44bc0e8
to preserve compatibility with go1.20 and older. At the time, our vendor.mod
still had go1.18 as minimum version requirement (see [1]), which got updated to go1.20
in 16063c7456, and go1.21 in f90b03ee5d
The version of BuildKit we use already started using context.WithoutCancel,
without a fallback, so we no longer can provide compatibility with older
versions of Go, which makes our compatiblity package redundant.
This patch removes the package, and updates our code to use stdlib's context
instead.
[1]: f6e44bc0e8/vendor.mod (L7)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Update to containerd 1.7.18, which now migrated to the errdefs module. The
existing errdefs package is now an alias for the module, and should no longer
be used directly.
This patch:
- updates the containerd dependency: https://github.com/containerd/containerd/compare/v1.7.17...v1.7.18
- replaces uses of the old package in favor of the new module
- adds a linter check to prevent accidental re-introduction of the old package
- adds a linter check to prevent using the "log" package, which was also
migrated to a separate module.
There are still some uses of the old package in (indirect) dependencies,
which should go away over time.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Use `image.Store` and `content.Store` stored in the ImageService struct
instead of fetching it every time from containerd client.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
In order for the cache in the classic builder to work we need to:
- use the came comparison function as the graph drivers implementation
- save the container config when commiting the image
- use all images to search a 'FROM "scratch"' image
- load all images if `cacheFrom` is empty
Signed-off-by: Djordje Lukic <djordje.lukic@docker.com>
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
Ensure that when removing an image, an image is checked consistently
against the images with the same target digest. Add unit testing around
delete.
Signed-off-by: Derek McGowan <derek@mcg.dev>
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>
This isn't something that user should do, but technically the dangling
images exist in the image store and user can pass its name (`moby-dangling@digest`).
Change it so rmi now recognizes that it's actually a dangling image and
doesn't handle it like a regular tagged image.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
Instead of passing a completely fresh context without any values, just
discard the cancellation.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
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>
Ports over all the previous image delete logic, such as:
- Introduce `prune` and `force` flags
- Introduce the concept of hard and soft image delete conflics, which represent:
- image referenced in multiple tags (soft conflict)
- image being used by a stopped container (soft conflict)
- image being used by a running container (hard conflict)
- Implement delete logic such as:
- if deleting by reference, and there are other references to the same image, just
delete the passed reference
- if deleting by reference, and there is only 1 reference and the image is being used
by a running container, throw an error if !force, or delete the reference and create
a dangling reference otherwise
- if deleting by imageID, and force is true, remove all tags (otherwise soft conflict)
- if imageID, check if stopped container is using the image (soft conflict), and
delete anyway if force
- if imageID was passed in, check if running container is using the image (hard conflict)
- if `prune` is true, and the image being deleted has dangling parents, remove them
This commit also implements logic to get image parents in c8d by comparing shared layers.
Signed-off-by: Laura Brehm <laurabrehm@hey.com>
This splits the ImageService methods to separate files, to closer
match the existing implementation, and to reduce the amount of code
per file, making it easier to read, and to reduce merge conflicts if
new functionality is added.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
