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stop grabbing container locks during ps
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Container queries are now served from the consistent in-memory db, and
don't need to grab a lock on every container being listed.

Signed-off-by: Fabio Kung <[email protected]>
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@fabiokung
fabiokung committed Jun 23, 2017
1 parent eed4c7b commit 8e425eb
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Showing 3 changed files with 68 additions and 125 deletions.
189 changes: 66 additions & 123 deletions daemon/list.go
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Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,6 @@ import (
"github.com/Sirupsen/logrus"
"github.com/docker/docker/api/types"
"github.com/docker/docker/api/types/filters"
networktypes "github.com/docker/docker/api/types/network"
"github.com/docker/docker/container"
"github.com/docker/docker/image"
"github.com/docker/docker/volume"
Expand Down Expand Up @@ -47,7 +46,7 @@ type iterationAction int

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

const (
// includeContainer is the action to include a container in the reducer.
Expand Down Expand Up @@ -83,9 +82,9 @@ type listContext struct {
exitAllowed []int

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

// taskFilter tells if we should filter based on wether a container is part of a task
taskFilter bool
Expand All @@ -102,7 +101,7 @@ type listContext struct {
}

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

func (r byContainerCreated) Len() int { return len(r) }
func (r byContainerCreated) Swap(i, j int) { r[i], r[j] = r[j], r[i] }
Expand All @@ -115,15 +114,17 @@ func (daemon *Daemon) Containers(config *types.ContainerListOptions) ([]*types.C
return daemon.reduceContainers(config, daemon.transformContainer)
}

func (daemon *Daemon) filterByNameIDMatches(ctx *listContext) []*container.Container {
func (daemon *Daemon) filterByNameIDMatches(view *container.View, ctx *listContext) ([]container.Snapshot, error) {
idSearch := false
names := ctx.filters.Get("name")
ids := ctx.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
return daemon.List()
all, err := view.All()
sort.Sort(sort.Reverse(byContainerCreated(all)))
return all, err
}

// idSearch will determine if we limit name matching to the IDs
Expand Down Expand Up @@ -158,38 +159,46 @@ func (daemon *Daemon) filterByNameIDMatches(ctx *listContext) []*container.Conta
}
}

cntrs := make([]*container.Container, 0, len(matches))
cntrs := make([]container.Snapshot, 0, len(matches))
for id := range matches {
if c := daemon.containers.Get(id); c != nil {
cntrs = append(cntrs, c)
c, err := view.Get(id)
if err != nil {
return nil, err
}
if c != nil {
cntrs = append(cntrs, *c)
}
}

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

return 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(config *types.ContainerListOptions, reducer containerReducer) ([]*types.Container, error) {
var (
view = daemon.containersReplica.Snapshot()
containers = []*types.Container{}
)

ctx, err := daemon.foldFilter(config)
ctx, err := daemon.foldFilter(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 locking and querying many more containers than intended
containerList := daemon.filterByNameIDMatches(ctx)
// end up querying many more containers than intended
containerList, err := daemon.filterByNameIDMatches(view, ctx)
if err != nil {
return nil, err
}

for _, container := range containerList {
t, err := daemon.reducePsContainer(container, ctx, reducer)
for i := range containerList {
t, err := daemon.reducePsContainer(&containerList[i], ctx, reducer)
if err != nil {
if err != errStopIteration {
return nil, err
Expand All @@ -206,23 +215,17 @@ func (daemon *Daemon) reduceContainers(config *types.ContainerListOptions, reduc
}

// reducePsContainer is the basic representation for a container as expected by the ps command.
func (daemon *Daemon) reducePsContainer(container *container.Container, ctx *listContext, reducer containerReducer) (*types.Container, error) {
container.Lock()

func (daemon *Daemon) reducePsContainer(container *container.Snapshot, ctx *listContext, reducer containerReducer) (*types.Container, error) {
// filter containers to return
action := includeContainerInList(container, ctx)
switch action {
switch includeContainerInList(container, ctx) {
case excludeContainer:
container.Unlock()
return nil, nil
case stopIteration:
container.Unlock()
return nil, errStopIteration
}

// transform internal container struct into api structs
newC, err := reducer(container, ctx)
container.Unlock()
if err != nil {
return nil, err
}
Expand All @@ -237,7 +240,7 @@ func (daemon *Daemon) reducePsContainer(container *container.Container, ctx *lis
}

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

if err := psFilters.Validate(acceptedPsFilterTags); err != nil {
Expand Down Expand Up @@ -294,18 +297,18 @@ func (daemon *Daemon) foldFilter(config *types.ContainerListOptions) (*listConte
return nil, err
}

var beforeContFilter, sinceContFilter *container.Container
var beforeContFilter, sinceContFilter *container.Snapshot

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

err = psFilters.WalkValues("since", func(value string) error {
sinceContFilter, err = daemon.GetContainer(value)
sinceContFilter, err = view.Get(value)
return err
})
if err != nil {
Expand Down Expand Up @@ -383,7 +386,7 @@ func portOp(key string, filter map[nat.Port]bool) func(value string) error {

// 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.Container, ctx *listContext) iterationAction {
func includeContainerInList(container *container.Snapshot, ctx *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 ctx.beforeFilter != nil {
Expand Down Expand Up @@ -422,7 +425,7 @@ func includeContainerInList(container *container.Container, ctx *listContext) it
}

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

Expand All @@ -440,7 +443,7 @@ func includeContainerInList(container *container.Container, ctx *listContext) it
if len(ctx.exitAllowed) > 0 {
shouldSkip := true
for _, code := range ctx.exitAllowed {
if code == container.ExitCode() && !container.Running && !container.StartedAt.IsZero() {
if code == container.ExitCode && !container.Running && !container.StartedAt.IsZero() {
shouldSkip = false
break
}
Expand All @@ -451,28 +454,34 @@ func includeContainerInList(container *container.Container, ctx *listContext) it
}

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

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

if ctx.filters.Include("volume") {
volumesByName := make(map[string]*volume.MountPoint)
for _, m := range container.MountPoints {
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 := ctx.filters.WalkValues("volume", func(value string) error {
if _, exist := container.MountPoints[value]; exist {
if _, exist := volumesByDestination[value]; exist {
return volumeExist
}
if _, exist := volumesByName[value]; exist {
Expand All @@ -489,7 +498,7 @@ func includeContainerInList(container *container.Container, ctx *listContext) it
if len(ctx.images) == 0 {
return excludeContainer
}
if !ctx.images[container.ImageID] {
if !ctx.images[image.ID(container.ImageID)] {
return excludeContainer
}
}
Expand All @@ -501,7 +510,7 @@ func includeContainerInList(container *container.Container, ctx *listContext) it
return networkExist
}
for _, nw := range container.NetworkSettings.Networks {
if nw.EndpointSettings == nil {
if nw == nil {
continue
}
if strings.HasPrefix(nw.NetworkID, value) {
Expand All @@ -518,7 +527,7 @@ func includeContainerInList(container *container.Container, ctx *listContext) it
if len(ctx.publish) > 0 {
shouldSkip := true
for port := range ctx.publish {
if _, ok := container.HostConfig.PortBindings[port]; ok {
if _, ok := container.PublishPorts[port]; ok {
shouldSkip = false
break
}
Expand All @@ -531,7 +540,7 @@ func includeContainerInList(container *container.Container, ctx *listContext) it
if len(ctx.expose) > 0 {
shouldSkip := true
for port := range ctx.expose {
if _, ok := container.Config.ExposedPorts[port]; ok {
if _, ok := container.ExposedPorts[port]; ok {
shouldSkip = false
break
}
Expand All @@ -545,104 +554,38 @@ func includeContainerInList(container *container.Container, ctx *listContext) it
}

// transformContainer generates the container type expected by the docker ps command.
func (daemon *Daemon) transformContainer(container *container.Container, ctx *listContext) (*types.Container, error) {
func (daemon *Daemon) transformContainer(container *container.Snapshot, ctx *listContext) (*types.Container, error) {
newC := &types.Container{
ID: container.ID,
Names: ctx.names[container.ID],
ImageID: container.ImageID.String(),
ID: container.ID,
Names: ctx.names[container.ID],
ImageID: container.ImageID,
Command: container.Command,
Created: container.Created.Unix(),
State: container.State,
Status: container.Status,
NetworkSettings: &container.NetworkSettings,
Ports: container.Ports,
Labels: container.Labels,
Mounts: container.Mounts,
}
if newC.Names == nil {
// Dead containers will often have no name, so make sure the response isn't null
newC.Names = []string{}
}
newC.HostConfig.NetworkMode = container.HostConfig.NetworkMode

image := container.Config.Image // if possible keep the original ref
if image != container.ImageID.String() {
image := container.Image // if possible keep the original ref
if image != container.ImageID {
id, _, err := daemon.GetImageIDAndPlatform(image)
if _, isDNE := err.(ErrImageDoesNotExist); err != nil && !isDNE {
return nil, err
}
if err != nil || id != container.ImageID {
image = container.ImageID.String()
if err != nil || id.String() != container.ImageID {
image = container.ImageID
}
}
newC.Image = image

if len(container.Args) > 0 {
args := []string{}
for _, arg := range container.Args {
if strings.Contains(arg, " ") {
args = append(args, fmt.Sprintf("'%s'", arg))
} else {
args = append(args, arg)
}
}
argsAsString := strings.Join(args, " ")

newC.Command = fmt.Sprintf("%s %s", container.Path, argsAsString)
} else {
newC.Command = container.Path
}
newC.Created = container.Created.Unix()
newC.State = container.State.StateString()
newC.Status = container.State.String()
newC.HostConfig.NetworkMode = string(container.HostConfig.NetworkMode)
// copy networks to avoid races
networks := make(map[string]*networktypes.EndpointSettings)
for name, network := range container.NetworkSettings.Networks {
if network == nil || network.EndpointSettings == nil {
continue
}
networks[name] = &networktypes.EndpointSettings{
EndpointID: network.EndpointID,
Gateway: network.Gateway,
IPAddress: network.IPAddress,
IPPrefixLen: network.IPPrefixLen,
IPv6Gateway: network.IPv6Gateway,
GlobalIPv6Address: network.GlobalIPv6Address,
GlobalIPv6PrefixLen: network.GlobalIPv6PrefixLen,
MacAddress: network.MacAddress,
NetworkID: network.NetworkID,
}
if network.IPAMConfig != nil {
networks[name].IPAMConfig = &networktypes.EndpointIPAMConfig{
IPv4Address: network.IPAMConfig.IPv4Address,
IPv6Address: network.IPAMConfig.IPv6Address,
}
}
}
newC.NetworkSettings = &types.SummaryNetworkSettings{Networks: networks}

newC.Ports = []types.Port{}
for port, bindings := range container.NetworkSettings.Ports {
p, err := nat.ParsePort(port.Port())
if err != nil {
return nil, err
}
if len(bindings) == 0 {
newC.Ports = append(newC.Ports, types.Port{
PrivatePort: uint16(p),
Type: port.Proto(),
})
continue
}
for _, binding := range bindings {
h, err := nat.ParsePort(binding.HostPort)
if err != nil {
return nil, err
}
newC.Ports = append(newC.Ports, types.Port{
PrivatePort: uint16(p),
PublicPort: uint16(h),
Type: port.Proto(),
IP: binding.HostIP,
})
}
}

newC.Labels = container.Config.Labels
newC.Mounts = addMountPoints(container)

return newC, nil
}

Expand Down
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