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watchtower/internal/actions/update.go

275 lines
8.5 KiB
Go

package actions
import (
"errors"
"strings"
"github.com/containrrr/watchtower/internal/util"
"github.com/containrrr/watchtower/pkg/container"
"github.com/containrrr/watchtower/pkg/lifecycle"
"github.com/containrrr/watchtower/pkg/session"
"github.com/containrrr/watchtower/pkg/sorter"
"github.com/containrrr/watchtower/pkg/types"
log "github.com/sirupsen/logrus"
)
// Update looks at the running Docker containers to see if any of the images
// used to start those containers have been updated. If a change is detected in
// any of the images, the associated containers are stopped and restarted with
// the new image.
func Update(client container.Client, params types.UpdateParams) (types.Report, error) {
log.Debug("Checking containers for updated images")
progress := &session.Progress{}
staleCount := 0
if params.LifecycleHooks {
lifecycle.ExecutePreChecks(client, params)
}
containers, err := client.ListContainers(params.Filter)
if err != nil {
return nil, err
}
staleCheckFailed := 0
for i, targetContainer := range containers {
stale, newestImage, err := client.IsContainerStale(targetContainer)
shouldUpdate := stale && !params.NoRestart && !params.MonitorOnly && !targetContainer.IsMonitorOnly()
if err == nil && shouldUpdate {
// Check to make sure we have all the necessary information for recreating the container
err = targetContainer.VerifyConfiguration()
// If the image information is incomplete and trace logging is enabled, log it for further diagnosis
if err != nil && log.IsLevelEnabled(log.TraceLevel) {
imageInfo := targetContainer.ImageInfo()
log.Tracef("Image info: %#v", imageInfo)
log.Tracef("Container info: %#v", targetContainer.ContainerInfo())
if imageInfo != nil {
log.Tracef("Image config: %#v", imageInfo.Config)
}
}
}
if err != nil {
log.Infof("Unable to update container %q: %v. Proceeding to next.", targetContainer.Name(), err)
stale = false
staleCheckFailed++
progress.AddSkipped(targetContainer, err)
} else {
progress.AddScanned(targetContainer, newestImage)
}
containers[i].Stale = stale
if stale {
staleCount++
}
}
containers, err = sorter.SortByDependencies(containers)
if err != nil {
return nil, err
}
UpdateImplicitRestart(containers)
var containersToUpdate []container.Container
if !params.MonitorOnly {
for _, c := range containers {
if !c.IsMonitorOnly() {
containersToUpdate = append(containersToUpdate, c)
progress.MarkForUpdate(c.ID())
}
}
}
if params.RollingRestart {
progress.UpdateFailed(performRollingRestart(containersToUpdate, client, params))
} else {
failedStop, stoppedImages := stopContainersInReversedOrder(containersToUpdate, client, params)
progress.UpdateFailed(failedStop)
failedStart := restartContainersInSortedOrder(containersToUpdate, client, params, stoppedImages)
progress.UpdateFailed(failedStart)
}
if params.LifecycleHooks {
lifecycle.ExecutePostChecks(client, params)
}
return progress.Report(), nil
}
func performRollingRestart(containers []container.Container, client container.Client, params types.UpdateParams) map[types.ContainerID]error {
cleanupImageIDs := make(map[types.ImageID]bool, len(containers))
failed := make(map[types.ContainerID]error, len(containers))
for i := len(containers) - 1; i >= 0; i-- {
if containers[i].ToRestart() {
err := stopStaleContainer(containers[i], client, params)
if err != nil {
failed[containers[i].ID()] = err
} else {
if err := restartStaleContainer(containers[i], client, params); err != nil {
failed[containers[i].ID()] = err
} else if containers[i].Stale {
// Only add (previously) stale containers' images to cleanup
cleanupImageIDs[containers[i].ImageID()] = true
}
}
}
}
if params.Cleanup {
cleanupImages(client, cleanupImageIDs)
}
return failed
}
func stopContainersInReversedOrder(containers []container.Container, client container.Client, params types.UpdateParams) (failed map[types.ContainerID]error, stopped map[types.ImageID]bool) {
failed = make(map[types.ContainerID]error, len(containers))
stopped = make(map[types.ImageID]bool, len(containers))
for i := len(containers) - 1; i >= 0; i-- {
if err := stopStaleContainer(containers[i], client, params); err != nil {
failed[containers[i].ID()] = err
} else {
// NOTE: If a container is restarted due to a dependency this might be empty
stopped[containers[i].SafeImageID()] = true
}
}
return
}
func stopStaleContainer(container container.Container, client container.Client, params types.UpdateParams) error {
if container.IsWatchtower() {
log.Debugf("This is the watchtower container %s", container.Name())
return nil
}
if !container.ToRestart() {
return nil
}
// Perform an additional check here to prevent us from stopping a linked container we cannot restart
if container.LinkedToRestarting {
if err := container.VerifyConfiguration(); err != nil {
return err
}
}
if params.LifecycleHooks {
skipUpdate, err := lifecycle.ExecutePreUpdateCommand(client, container)
if err != nil {
log.Error(err)
log.Info("Skipping container as the pre-update command failed")
return err
}
if skipUpdate {
log.Debug("Skipping container as the pre-update command returned exit code 75 (EX_TEMPFAIL)")
return errors.New("skipping container as the pre-update command returned exit code 75 (EX_TEMPFAIL)")
}
}
if err := client.StopContainer(container, params.Timeout); err != nil {
log.Error(err)
return err
}
return nil
}
func restartContainersInSortedOrder(containers []container.Container, client container.Client, params types.UpdateParams, stoppedImages map[types.ImageID]bool) map[types.ContainerID]error {
cleanupImageIDs := make(map[types.ImageID]bool, len(containers))
failed := make(map[types.ContainerID]error, len(containers))
for _, c := range containers {
if !c.ToRestart() {
continue
}
if stoppedImages[c.SafeImageID()] {
if err := restartStaleContainer(c, client, params); err != nil {
failed[c.ID()] = err
} else if c.Stale {
// Only add (previously) stale containers' images to cleanup
cleanupImageIDs[c.ImageID()] = true
}
}
}
if params.Cleanup {
cleanupImages(client, cleanupImageIDs)
}
return failed
}
func cleanupImages(client container.Client, imageIDs map[types.ImageID]bool) {
for imageID := range imageIDs {
if imageID == "" {
continue
}
if err := client.RemoveImageByID(imageID); err != nil {
log.Error(err)
}
}
}
func restartStaleContainer(container container.Container, client container.Client, params types.UpdateParams) error {
// Since we can't shutdown a watchtower container immediately, we need to
// start the new one while the old one is still running. This prevents us
// from re-using the same container name so we first rename the current
// instance so that the new one can adopt the old name.
if container.IsWatchtower() {
if err := client.RenameContainer(container, util.RandName()); err != nil {
log.Error(err)
return nil
}
}
if !params.NoRestart {
if newContainerID, err := client.StartContainer(container); err != nil {
log.Error(err)
return err
} else if container.ToRestart() && params.LifecycleHooks {
lifecycle.ExecutePostUpdateCommand(client, newContainerID)
}
}
return nil
}
// UpdateImplicitRestart iterates through the passed containers, setting the
// `LinkedToRestarting` flag if any of it's linked containers are marked for restart
func UpdateImplicitRestart(containers []container.Container) {
for ci, c := range containers {
if c.ToRestart() {
// The container is already marked for restart, no need to check
continue
}
if link := linkedContainerMarkedForRestart(c.Links(), containers); link != "" {
log.WithFields(log.Fields{
"restarting": link,
"linked": c.Name(),
}).Debug("container is linked to restarting")
// NOTE: To mutate the array, the `c` variable cannot be used as it's a copy
containers[ci].LinkedToRestarting = true
}
}
}
// linkedContainerMarkedForRestart returns the name of the first link that matches a
// container marked for restart
func linkedContainerMarkedForRestart(links []string, containers []container.Container) string {
for _, linkName := range links {
// Since the container names need to start with '/', let's prepend it if it's missing
if !strings.HasPrefix(linkName, "/") {
linkName = "/" + linkName
}
for _, candidate := range containers {
if candidate.Name() == linkName && candidate.ToRestart() {
return linkName
}
}
}
return ""
}