filters: Reduce duplication of bool filter parsing and invalidFilter error
When working on images prune for containerd branch I noticed that the logic for parsing the filter value as boolean is duplicated in multiple places and each package has its own invalidFilter type which basically does the same thing.

**- What I did**
- Removed all duplicated invalidFilter types
- Replaced repeated pattern of parsing boolean filter with the usage of `GetBoolOrDefault`

**- How to verify it**
CI, lint, tests

**- Description for the changelog**

**- A picture of a cute animal (not mandatory but encouraged)**


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

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

	"github.com/docker/docker/api/types"
	"github.com/docker/docker/api/types/filters"
	imagetypes "github.com/docker/docker/api/types/image"
	"github.com/docker/docker/container"
	"github.com/docker/docker/daemon/images"
	"github.com/docker/docker/errdefs"
	"github.com/docker/docker/image"
	"github.com/docker/go-connections/nat"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
)

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

// containerReducer represents a reducer for a container.
// Returns the object to serialize by the api.
type containerReducer func(context.Context, *container.Snapshot, *listContext) (*types.Container, error)

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

// errStopIteration makes the iterator to stop without returning an error.
var errStopIteration = errors.New("container list iteration stopped")

// 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 types.ContainerListOptions.
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

	// ContainerListOptions is the filters set by the user
	*types.ContainerListOptions
}

// 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 *types.ContainerListOptions) ([]*types.Container, error) {
	return daemon.reduceContainers(ctx, config, daemon.refreshImage)
}

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
}

// reduceContainers parses the user's filtering options and generates the list of containers to return based on a reducer.
func (daemon *Daemon) reduceContainers(ctx context.Context, config *types.ContainerListOptions, reducer containerReducer) ([]*types.Container, error) {
	if err := config.Filters.Validate(acceptedPsFilterTags); err != nil {
		return nil, err
	}

	var (
		view       = daemon.containersReplica.Snapshot()
		containers = []*types.Container{}
	)

	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 {
		t, err := daemon.reducePsContainer(ctx, &containerList[i], filter, reducer)
		if err != nil {
			if err != errStopIteration {
				return nil, err
			}
			break
		}
		if t != nil {
			containers = append(containers, t)
			filter.idx++
		}
	}

	return containers, nil
}

// reducePsContainer is the basic representation for a container as expected by the ps command.
func (daemon *Daemon) reducePsContainer(ctx context.Context, container *container.Snapshot, filter *listContext, reducer containerReducer) (*types.Container, error) {
	// filter containers to return
	switch includeContainerInList(container, filter) {
	case excludeContainer:
		return nil, nil
	case stopIteration:
		return nil, errStopIteration
	}

	// transform internal container struct into api structs
	newC, err := reducer(ctx, container, filter)
	if err != nil {
		return nil, err
	}

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

// foldFilter generates the container filter based on the user's filtering options.
func (daemon *Daemon) foldFilter(ctx context.Context, view *container.View, config *types.ContainerListOptions) (*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 err
		}
		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 invalidFilter{"status", value}
		}

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

	var taskFilter, isTask bool
	if psFilters.Contains("is-task") {
		if psFilters.ExactMatch("is-task", "true") {
			taskFilter = true
			isTask = true
		} else if psFilters.ExactMatch("is-task", "false") {
			taskFilter = true
			isTask = false
		} else {
			return nil, invalidFilter{"is-task", psFilters.Get("is-task")}
		}
	}

	err = psFilters.WalkValues("health", func(value string) error {
		if !container.IsValidHealthString(value) {
			return errdefs.InvalidParameter(errors.Errorf("Unrecognised 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
		psFilters.WalkValues("ancestor", func(ancestor string) error {
			img, err := daemon.imageService.GetImage(ctx, ancestor, imagetypes.GetImageOpts{})
			if err != nil {
				logrus.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
			populateImageFilterByParents(imagesFilter, img.ID(), daemon.imageService.Children)
			return nil
		})
	}

	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,
		ContainerListOptions: 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]types.MountPoint)
		for _, m := range container.Mounts {
			if m.Name != "" {
				volumesByName[m.Name] = m
			} else {
				volumesByName[m.Source] = m
			}
		}
		volumesByDestination := make(map[string]types.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
func (daemon *Daemon) refreshImage(ctx context.Context, s *container.Snapshot, filter *listContext) (*types.Container, error) {
	c := s.Container
	tmpImage := s.Image // keep the original ref if still valid (hasn't changed)
	if tmpImage != s.ImageID {
		img, err := daemon.imageService.GetImage(ctx, tmpImage, imagetypes.GetImageOpts{})
		if _, isDNE := err.(images.ErrImageDoesNotExist); err != nil && !isDNE {
			return nil, err
		}
		if err != nil || img.ImageID() != s.ImageID {
			// ref changed, we need to use original ID
			tmpImage = s.ImageID
		}
	}
	c.Image = tmpImage
	return &c, nil
}

func populateImageFilterByParents(ancestorMap map[image.ID]bool, imageID image.ID, getChildren func(image.ID) []image.ID) {
	if !ancestorMap[imageID] {
		for _, id := range getChildren(imageID) {
			populateImageFilterByParents(ancestorMap, id, getChildren)
		}
		ancestorMap[imageID] = true
	}
}

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

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

	"github.com/docker/docker/api/types"
	"github.com/docker/docker/api/types/filters"
	imagetypes "github.com/docker/docker/api/types/image"
	"github.com/docker/docker/container"
	"github.com/docker/docker/daemon/images"
	"github.com/docker/docker/errdefs"
	"github.com/docker/docker/image"
	"github.com/docker/go-connections/nat"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
)

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

// containerReducer represents a reducer for a container.
// Returns the object to serialize by the api.
type containerReducer func(context.Context, *container.Snapshot, *listContext) (*types.Container, error)

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

// errStopIteration makes the iterator to stop without returning an error.
var errStopIteration = errors.New("container list iteration stopped")

// 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 types.ContainerListOptions.
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

	// ContainerListOptions is the filters set by the user
	*types.ContainerListOptions
}

// 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 *types.ContainerListOptions) ([]*types.Container, error) {
	return daemon.reduceContainers(ctx, config, daemon.refreshImage)
}

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
}

// reduceContainers parses the user's filtering options and generates the list of containers to return based on a reducer.
func (daemon *Daemon) reduceContainers(ctx context.Context, config *types.ContainerListOptions, reducer containerReducer) ([]*types.Container, error) {
	if err := config.Filters.Validate(acceptedPsFilterTags); err != nil {
		return nil, err
	}

	var (
		view       = daemon.containersReplica.Snapshot()
		containers = []*types.Container{}
	)

	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 {
		t, err := daemon.reducePsContainer(ctx, &containerList[i], filter, reducer)
		if err != nil {
			if err != errStopIteration {
				return nil, err
			}
			break
		}
		if t != nil {
			containers = append(containers, t)
			filter.idx++
		}
	}

	return containers, nil
}

// reducePsContainer is the basic representation for a container as expected by the ps command.
func (daemon *Daemon) reducePsContainer(ctx context.Context, container *container.Snapshot, filter *listContext, reducer containerReducer) (*types.Container, error) {
	// filter containers to return
	switch includeContainerInList(container, filter) {
	case excludeContainer:
		return nil, nil
	case stopIteration:
		return nil, errStopIteration
	}

	// transform internal container struct into api structs
	newC, err := reducer(ctx, container, filter)
	if err != nil {
		return nil, err
	}

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

// foldFilter generates the container filter based on the user's filtering options.
func (daemon *Daemon) foldFilter(ctx context.Context, view *container.View, config *types.ContainerListOptions) (*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
		psFilters.WalkValues("ancestor", func(ancestor string) error {
			img, err := daemon.imageService.GetImage(ctx, ancestor, imagetypes.GetImageOpts{})
			if err != nil {
				logrus.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
			populateImageFilterByParents(imagesFilter, img.ID(), daemon.imageService.Children)
			return nil
		})
	}

	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,
		ContainerListOptions: 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]types.MountPoint)
		for _, m := range container.Mounts {
			if m.Name != "" {
				volumesByName[m.Name] = m
			} else {
				volumesByName[m.Source] = m
			}
		}
		volumesByDestination := make(map[string]types.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
func (daemon *Daemon) refreshImage(ctx context.Context, s *container.Snapshot, filter *listContext) (*types.Container, error) {
	c := s.Container
	tmpImage := s.Image // keep the original ref if still valid (hasn't changed)
	if tmpImage != s.ImageID {
		img, err := daemon.imageService.GetImage(ctx, tmpImage, imagetypes.GetImageOpts{})
		if _, isDNE := err.(images.ErrImageDoesNotExist); err != nil && !isDNE {
			return nil, err
		}
		if err != nil || img.ImageID() != s.ImageID {
			// ref changed, we need to use original ID
			tmpImage = s.ImageID
		}
	}
	c.Image = tmpImage
	return &c, nil
}

func populateImageFilterByParents(ancestorMap map[image.ID]bool, imageID image.ID, getChildren func(image.ID) []image.ID) {
	if !ancestorMap[imageID] {
		for _, id := range getChildren(imageID) {
			populateImageFilterByParents(ancestorMap, id, getChildren)
		}
		ancestorMap[imageID] = true
	}
}

Perhaps that may work (definitely not for this PR though!). Will have to give it another (closer) look to see what everything would look like. The "multiple values" (and in many cases rather ambiguous) is rather awkward with the filters.