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mirror of https://github.com/containrrr/watchtower.git synced 2024-12-15 09:14:13 +02:00
watchtower/internal/actions/update.go
2019-07-22 12:10:57 +02:00

122 lines
3.0 KiB
Go

package actions
import (
"github.com/containrrr/watchtower/internal/util"
"github.com/containrrr/watchtower/pkg/container"
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 UpdateParams) error {
log.Debug("Checking containers for updated images")
containers, err := client.ListContainers(params.Filter)
if err != nil {
return err
}
for i, container := range containers {
stale, err := client.IsContainerStale(container)
if err != nil {
log.Infof("Unable to update container %s. Proceeding to next.", containers[i].Name())
log.Debug(err)
stale = false
}
containers[i].Stale = stale
}
containers, err = container.SortByDependencies(containers)
if err != nil {
return err
}
checkDependencies(containers)
if params.MonitorOnly {
return nil
}
stopContainersInReversedOrder(containers, client, params)
restartContainersInSortedOrder(containers, client, params)
return nil
}
func stopContainersInReversedOrder(containers []container.Container, client container.Client, params UpdateParams) {
for i := len(containers) - 1; i >= 0; i-- {
stopStaleContainer(containers[i], client, params)
}
}
func stopStaleContainer(container container.Container, client container.Client, params UpdateParams) {
if container.IsWatchtower() {
log.Debugf("This is the watchtower container %s", container.Name())
return
}
if !container.Stale {
return
}
err := client.StopContainer(container, params.Timeout)
if err != nil {
log.Error(err)
}
}
func restartContainersInSortedOrder(containers []container.Container, client container.Client, params UpdateParams) {
for _, container := range containers {
if !container.Stale {
continue
}
restartStaleContainer(container, client, params)
}
}
func restartStaleContainer(container container.Container, client container.Client, params UpdateParams) {
// 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
}
}
if !params.NoRestart {
if err := client.StartContainer(container); err != nil {
log.Error(err)
}
}
if params.Cleanup {
if err := client.RemoveImage(container); err != nil {
log.Error(err)
}
}
}
func checkDependencies(containers []container.Container) {
for i, parent := range containers {
if parent.Stale {
continue
}
LinkLoop:
for _, linkName := range parent.Links() {
for _, child := range containers {
if child.Name() == linkName && child.Stale {
containers[i].Stale = true
break LinkLoop
}
}
}
}
}