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daemon/list.go

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package daemon // import "github.com/docker/docker/daemon"

import (
    "context"
    "fmt"
    "sort"
    "strconv"
    "strings"

    "github.com/containerd/log"
    "github.com/docker/docker/api/types/backend"
    containertypes "github.com/docker/docker/api/types/container"
    "github.com/docker/docker/api/types/filters"
    "github.com/docker/docker/container"
    "github.com/docker/docker/errdefs"
    "github.com/docker/docker/image"
    "github.com/docker/go-connections/nat"
    "github.com/pkg/errors"
)

var acceptedPsFilterTags = map[string]bool{
    "ancestor":  true,
    "before":    true,
    "exited":    true,
    "id":        true,
    "isolation": true,
    "label":     true,
    "name":      true,
    "status":    true,
    "health":    true,
    "since":     true,
    "volume":    true,
    "network":   true,
    "is-task":   true,
    "publish":   true,
    "expose":    true,
}

// iterationAction represents possible outcomes happening during the container iteration.
type iterationAction int

const (
    // includeContainer is the action to include a container.
    includeContainer iterationAction = iota
    // excludeContainer is the action to exclude a container.
    excludeContainer
    // stopIteration is the action to stop iterating over the list of containers.
    stopIteration
)

// List returns an array of all containers registered in the daemon.
func (daemon *Daemon) List() []*container.Container {
    return daemon.containers.List()
}

// listContext is the daemon generated filtering to iterate over containers.
// This is created based on the user specification from [containertypes.ListOptions].
type listContext struct {
    // idx is the container iteration index for this context
    idx int
    // ancestorFilter tells whether it should check ancestors or not
    ancestorFilter bool
    // names is a list of container names to filter with
    names map[string][]string
    // images is a list of images to filter with
    images map[image.ID]bool
    // filters is a collection of arguments to filter with, specified by the user
    filters filters.Args
    // exitAllowed is a list of exit codes allowed to filter with
    exitAllowed []int

    // beforeFilter is a filter to ignore containers that appear before the one given
    beforeFilter *container.Snapshot
    // sinceFilter is a filter to stop the filtering when the iterator arrives to the given container
    sinceFilter *container.Snapshot

    // taskFilter tells if we should filter based on whether a container is part of a task
    taskFilter bool
    // isTask tells us if we should filter container that is a task (true) or not (false)
    isTask bool

    // publish is a list of published ports to filter with
    publish map[nat.Port]bool
    // expose is a list of exposed ports to filter with
    expose map[nat.Port]bool

    // ListOptions is the filters set by the user
    *containertypes.ListOptions
}

// byCreatedDescending is a temporary type used to sort a list of containers by creation time.
type byCreatedDescending []container.Snapshot

func (r byCreatedDescending) Len() int      { return len(r) }
func (r byCreatedDescending) Swap(i, j int) { r[i], r[j] = r[j], r[i] }
func (r byCreatedDescending) Less(i, j int) bool {
    return r[j].CreatedAt.UnixNano() < r[i].CreatedAt.UnixNano()
}

// Containers returns the list of containers to show given the user's filtering.
func (daemon *Daemon) Containers(ctx context.Context, config *containertypes.ListOptions) ([]*containertypes.Summary, error) {
    if err := config.Filters.Validate(acceptedPsFilterTags); err != nil {
        return nil, err
    }

    var (
        view       = daemon.containersReplica.Snapshot()
        containers = []*containertypes.Summary{}
    )

    filter, err := daemon.foldFilter(ctx, view, config)
    if err != nil {
        return nil, err
    }

    // fastpath to only look at a subset of containers if specific name
    // or ID matches were provided by the user--otherwise we potentially
    // end up querying many more containers than intended
    containerList, err := daemon.filterByNameIDMatches(view, filter)
    if err != nil {
        return nil, err
    }

    for i := range containerList {
        currentContainer := &containerList[i]
        switch includeContainerInList(currentContainer, filter) {
        case excludeContainer:
            continue
        case stopIteration:
            return containers, nil
        }

        // transform internal container struct into api structs
        newC, err := daemon.refreshImage(ctx, currentContainer)
        if err != nil {
            return nil, err
        }

        // release lock because size calculation is slow
        if filter.Size {
            sizeRw, sizeRootFs, err := daemon.imageService.GetContainerLayerSize(ctx, newC.ID)
            if err != nil {
                return nil, err
            }
            newC.SizeRw = sizeRw
            newC.SizeRootFs = sizeRootFs
        }
        if newC != nil {
            containers = append(containers, newC)
            filter.idx++
        }
    }

    return containers, nil
}

func (daemon *Daemon) filterByNameIDMatches(view *container.View, filter *listContext) ([]container.Snapshot, error) {
    idSearch := false
    names := filter.filters.Get("name")
    ids := filter.filters.Get("id")
    if len(names)+len(ids) == 0 {
        // if name or ID filters are not in use, return to
        // standard behavior of walking the entire container
        // list from the daemon's in-memory store
        all, err := view.All()
        if err != nil {
            return nil, err
        }
        sort.Sort(byCreatedDescending(all))
        return all, nil
    }

    // idSearch will determine if we limit name matching to the IDs
    // matched from any IDs which were specified as filters
    if len(ids) > 0 {
        idSearch = true
    }

    matches := make(map[string]bool)
    // find ID matches; errors represent "not found" and can be ignored
    for _, id := range ids {
        if fullID, err := daemon.containersReplica.GetByPrefix(id); err == nil {
            matches[fullID] = true
        }
    }

    // look for name matches; if ID filtering was used, then limit the
    // search space to the matches map only; errors represent "not found"
    // and can be ignored
    if len(names) > 0 {
        for id, idNames := range filter.names {
            // if ID filters were used and no matches on that ID were
            // found, continue to next ID in the list
            if idSearch && !matches[id] {
                continue
            }
            for _, eachName := range idNames {
                // match both on container name with, and without slash-prefix
                if filter.filters.Match("name", eachName) || filter.filters.Match("name", strings.TrimPrefix(eachName, "/")) {
                    matches[id] = true
                }
            }
        }
    }

    cntrs := make([]container.Snapshot, 0, len(matches))
    for id := range matches {
        c, err := view.Get(id)
        if err != nil {
            if errdefs.IsNotFound(err) {
                // ignore error
                continue
            }
            return nil, err
        }
        cntrs = append(cntrs, *c)
    }

    // Restore sort-order after filtering
    // Created gives us nanosec resolution for sorting
    sort.Sort(byCreatedDescending(cntrs))

    return cntrs, nil
}

// foldFilter generates the container filter based on the user's filtering options.
func (daemon *Daemon) foldFilter(ctx context.Context, view *container.View, config *containertypes.ListOptions) (*listContext, error) {
    psFilters := config.Filters

    var filtExited []int

    err := psFilters.WalkValues("exited", func(value string) error {
        code, err := strconv.Atoi(value)
        if err != nil {
            return errdefs.InvalidParameter(errors.Wrapf(err, "invalid filter 'exited=%s'", value))
        }
        filtExited = append(filtExited, code)
        return nil
    })
    if err != nil {
        return nil, err
    }

    err = psFilters.WalkValues("status", func(value string) error {
        if !container.IsValidStateString(value) {
            return errdefs.InvalidParameter(fmt.Errorf("invalid filter 'status=%s'", value))
        }

        config.All = true
        return nil
    })
    if err != nil {
        return nil, err
    }

    taskFilter := psFilters.Contains("is-task")
    isTask, err := psFilters.GetBoolOrDefault("is-task", false)
    if err != nil {
        return nil, err
    }

    err = psFilters.WalkValues("health", func(value string) error {
        if !container.IsValidHealthString(value) {
            return errdefs.InvalidParameter(fmt.Errorf("unrecognized filter value for health: %s", value))
        }

        return nil
    })
    if err != nil {
        return nil, err
    }

    var beforeContFilter, sinceContFilter *container.Snapshot

    err = psFilters.WalkValues("before", func(value string) error {
        beforeContFilter, err = idOrNameFilter(view, value)
        return err
    })
    if err != nil {
        return nil, err
    }

    err = psFilters.WalkValues("since", func(value string) error {
        sinceContFilter, err = idOrNameFilter(view, value)
        return err
    })
    if err != nil {
        return nil, err
    }

    imagesFilter := map[image.ID]bool{}
    var ancestorFilter bool
    if psFilters.Contains("ancestor") {
        ancestorFilter = true
        err := psFilters.WalkValues("ancestor", func(ancestor string) error {
            img, err := daemon.imageService.GetImage(ctx, ancestor, backend.GetImageOpts{})
            if err != nil {
                log.G(ctx).Warnf("Error while looking up for image %v", ancestor)
                return nil
            }
            if imagesFilter[img.ID()] {
                // Already seen this ancestor, skip it
                return nil
            }
            // Then walk down the graph and put the imageIds in imagesFilter
            return populateImageFilterByParents(ctx, imagesFilter, img.ID(), daemon.imageService.Children)
        })
        if err != nil {
            return nil, err
        }
    }

    publishFilter := map[nat.Port]bool{}
    err = psFilters.WalkValues("publish", portOp("publish", publishFilter))
    if err != nil {
        return nil, err
    }

    exposeFilter := map[nat.Port]bool{}
    err = psFilters.WalkValues("expose", portOp("expose", exposeFilter))
    if err != nil {
        return nil, err
    }

    return &listContext{
        filters:        psFilters,
        ancestorFilter: ancestorFilter,
        images:         imagesFilter,
        exitAllowed:    filtExited,
        beforeFilter:   beforeContFilter,
        sinceFilter:    sinceContFilter,
        taskFilter:     taskFilter,
        isTask:         isTask,
        publish:        publishFilter,
        expose:         exposeFilter,
        ListOptions:    config,
        names:          view.GetAllNames(),
    }, nil
}

func idOrNameFilter(view *container.View, value string) (*container.Snapshot, error) {
    filter, err := view.Get(value)
    if err != nil && errdefs.IsNotFound(err) {
        // Try name search instead
        found := ""
        for id, idNames := range view.GetAllNames() {
            for _, eachName := range idNames {
                if strings.TrimPrefix(value, "/") == strings.TrimPrefix(eachName, "/") {
                    if found != "" && found != id {
                        return nil, err
                    }
                    found = id
                }
            }
        }
        if found != "" {
            filter, err = view.Get(found)
        }
    }
    return filter, err
}

func portOp(key string, filter map[nat.Port]bool) func(value string) error {
    return func(value string) error {
        if strings.Contains(value, ":") {
            return fmt.Errorf("filter for '%s' should not contain ':': %s", key, value)
        }
        // support two formats, original format <portnum>/[<proto>] or <startport-endport>/[<proto>]
        proto, port := nat.SplitProtoPort(value)
        start, end, err := nat.ParsePortRange(port)
        if err != nil {
            return fmt.Errorf("error while looking up for %s %s: %s", key, value, err)
        }
        for i := start; i <= end; i++ {
            p, err := nat.NewPort(proto, strconv.FormatUint(i, 10))
            if err != nil {
                return fmt.Errorf("error while looking up for %s %s: %s", key, value, err)
            }
            filter[p] = true
        }
        return nil
    }
}

// includeContainerInList decides whether a container should be included in the output or not based in the filter.
// It also decides if the iteration should be stopped or not.
func includeContainerInList(container *container.Snapshot, filter *listContext) iterationAction {
    // Do not include container if it's in the list before the filter container.
    // Set the filter container to nil to include the rest of containers after this one.
    if filter.beforeFilter != nil {
        if container.ID == filter.beforeFilter.ID {
            filter.beforeFilter = nil
        }
        return excludeContainer
    }

    // Stop iteration when the container arrives to the filter container
    if filter.sinceFilter != nil {
        if container.ID == filter.sinceFilter.ID {
            return stopIteration
        }
    }

    // Do not include container if it's stopped and we're not filters
    if !container.Running && !filter.All && filter.Limit <= 0 {
        return excludeContainer
    }

    // Do not include container if the name doesn't match
    if !filter.filters.Match("name", container.Name) && !filter.filters.Match("name", strings.TrimPrefix(container.Name, "/")) {
        return excludeContainer
    }

    // Do not include container if the id doesn't match
    if !filter.filters.Match("id", container.ID) {
        return excludeContainer
    }

    if filter.taskFilter {
        if filter.isTask != container.Managed {
            return excludeContainer
        }
    }

    // Do not include container if any of the labels don't match
    if !filter.filters.MatchKVList("label", container.Labels) {
        return excludeContainer
    }

    // Do not include container if isolation doesn't match
    if excludeContainer == excludeByIsolation(container, filter) {
        return excludeContainer
    }

    // Stop iteration when the index is over the limit
    if filter.Limit > 0 && filter.idx == filter.Limit {
        return stopIteration
    }

    // Do not include container if its exit code is not in the filter
    if len(filter.exitAllowed) > 0 {
        shouldSkip := true
        for _, code := range filter.exitAllowed {
            if code == container.ExitCode && !container.Running && !container.StartedAt.IsZero() {
                shouldSkip = false
                break
            }
        }
        if shouldSkip {
            return excludeContainer
        }
    }

    // Do not include container if its status doesn't match the filter
    if !filter.filters.Match("status", container.State) {
        return excludeContainer
    }

    // Do not include container if its health doesn't match the filter
    if !filter.filters.ExactMatch("health", container.Health) {
        return excludeContainer
    }

    if filter.filters.Contains("volume") {
        volumesByName := make(map[string]containertypes.MountPoint)
        for _, m := range container.Mounts {
            if m.Name != "" {
                volumesByName[m.Name] = m
            } else {
                volumesByName[m.Source] = m
            }
        }
        volumesByDestination := make(map[string]containertypes.MountPoint)
        for _, m := range container.Mounts {
            if m.Destination != "" {
                volumesByDestination[m.Destination] = m
            }
        }

        volumeExist := fmt.Errorf("volume mounted in container")
        err := filter.filters.WalkValues("volume", func(value string) error {
            if _, exist := volumesByDestination[value]; exist {
                return volumeExist
            }
            if _, exist := volumesByName[value]; exist {
                return volumeExist
            }
            return nil
        })
        if err != volumeExist {
            return excludeContainer
        }
    }

    if filter.ancestorFilter {
        if len(filter.images) == 0 {
            return excludeContainer
        }
        if !filter.images[image.ID(container.ImageID)] {
            return excludeContainer
        }
    }

    var (
        networkExist = errors.New("container part of network")
        noNetworks   = errors.New("container is not part of any networks")
    )
    if filter.filters.Contains("network") {
        err := filter.filters.WalkValues("network", func(value string) error {
            if container.NetworkSettings == nil {
                return noNetworks
            }
            if _, ok := container.NetworkSettings.Networks[value]; ok {
                return networkExist
            }
            for _, nw := range container.NetworkSettings.Networks {
                if nw == nil {
                    continue
                }
                if strings.HasPrefix(nw.NetworkID, value) {
                    return networkExist
                }
            }
            return nil
        })
        if err != networkExist {
            return excludeContainer
        }
    }

    if len(filter.expose) > 0 || len(filter.publish) > 0 {
        var (
            shouldSkip    = true
            publishedPort nat.Port
            exposedPort   nat.Port
        )
        for _, port := range container.Ports {
            publishedPort = nat.Port(fmt.Sprintf("%d/%s", port.PublicPort, port.Type))
            exposedPort = nat.Port(fmt.Sprintf("%d/%s", port.PrivatePort, port.Type))
            if ok := filter.publish[publishedPort]; ok {
                shouldSkip = false
                break
            } else if ok := filter.expose[exposedPort]; ok {
                shouldSkip = false
                break
            }
        }
        if shouldSkip {
            return excludeContainer
        }
    }

    return includeContainer
}

// refreshImage checks if the Image ref still points to the correct ID, and
// updates the ref to the actual ID when it doesn't.
// This happens when the image with a reference that was used to create
// container was deleted or updated and now resolves to a different ID.
//
// For example:
// $ docker run -d busybox:latest
// $ docker ps -a
// CONTAINER ID   IMAGE     COMMAND   CREATED         STATUS                     PORTS     NAMES
// b0318bca5aef   busybox   "sh"      4 seconds ago   Exited (0) 3 seconds ago             ecstatic_beaver
//
// After some time, busybox image got updated on the Docker Hub:
// $ docker pull busybox:latest
//
// So now busybox:latest points to a different digest, but that doesn't impact
// the ecstatic_beaver container which was still created under an older
// version. In this case, it should still point to the original image ID it was
// created from.
//
// $ docker ps -a
// CONTAINER ID   IMAGE          COMMAND   CREATED       STATUS                  PORTS     NAMES
// b0318bca5aef   3fbc63216742   "sh"      3 years ago   Exited (0) 3 years ago            ecstatic_beaver
func (daemon *Daemon) refreshImage(ctx context.Context, s *container.Snapshot) (*containertypes.Summary, error) {
    c := s.Summary

    // s.Image is the image reference passed by the user to create an image
    //         can be a:
    //         - name (like nginx, ubuntu:latest, docker.io/library/busybox:latest),
    //         - truncated ID (abcdef),
    //         - full digest (sha256:abcdef...)
    //
    // s.ImageID is the ID of the image that s.Image resolved to at the time
    // of the container creation. It's always a full digest.

    // If these match, there's nothing to refresh.
    if s.Image == s.ImageID {
        return &c, nil
    }

    // Check if the image reference still resolves to the same digest.
    img, err := daemon.imageService.GetImage(ctx, s.Image, backend.GetImageOpts{})
    // If the image is no longer found or can't be resolved for some other
    // reason. Update the Image to the specific ID of the original image it
    // resolved to when the container was created.
    if err != nil {
        if !errdefs.IsNotFound(err) {
            log.G(ctx).WithFields(log.Fields{
                "error":       err,
                "containerID": c.ID,
                "image":       s.Image,
                "imageID":     s.ImageID,
            }).Warn("failed to resolve container image")
        }
        c.Image = s.ImageID
        return &c, nil
    }

    // Also update the image to the specific image ID, if the Image now
    // resolves to a different ID.
    if img.ImageID() != s.ImageID {
        c.Image = s.ImageID
    }

    return &c, nil
}

func populateImageFilterByParents(ctx context.Context, ancestorMap map[image.ID]bool, imageID image.ID, getChildren func(context.Context, image.ID) ([]image.ID, error)) error {
    if !ancestorMap[imageID] {
        children, err := getChildren(ctx, imageID)
        if err != nil {
            return err
        }
        for _, id := range children {
            if err := populateImageFilterByParents(ctx, ancestorMap, id, getChildren); err != nil {
                return err
            }
        }
        ancestorMap[imageID] = true
    }
    return nil
}