package actions import ( "errors" "fmt" "github.com/containrrr/watchtower/pkg/filters" "github.com/containrrr/watchtower/pkg/sorter" "sort" "strings" "time" "github.com/opencontainers/runc/Godeps/_workspace/src/github.com/Sirupsen/logrus" log "github.com/sirupsen/logrus" "github.com/containrrr/watchtower/pkg/container" ) // CheckForMultipleWatchtowerInstances will ensure that there are not multiple instances of the // watchtower running simultaneously. If multiple watchtower containers are detected, this function // will stop and remove all but the most recently started container. func CheckForMultipleWatchtowerInstances(client container.Client, cleanup bool) error { awaitDockerClient() containers, err := client.ListContainers(filters.WatchtowerContainersFilter) if err != nil { log.Fatal(err) return err } if len(containers) <= 1 { log.Debug("There are no additional watchtower containers") return nil } log.Info("Found multiple running watchtower instances. Cleaning up.") return cleanupExcessWatchtowers(containers, client, cleanup) } func cleanupExcessWatchtowers(containers []container.Container, client container.Client, cleanup bool) error { var cleanupErrors int var stopErrors int sort.Sort(sorter.ByCreated(containers)) allContainersExceptLast := containers[0 : len(containers)-1] for _, c := range allContainersExceptLast { if err := client.StopContainer(c, 60); err != nil { // logging the original here as we're just returning a count logrus.Error(err) stopErrors++ continue } if cleanup { if err := client.RemoveImageByID(c.ImageID()); err != nil { // logging the original here as we're just returning a count logrus.Error(err) cleanupErrors++ } } } return createErrorIfAnyHaveOccurred(stopErrors, cleanupErrors) } func createErrorIfAnyHaveOccurred(c int, i int) error { if c == 0 && i == 0 { return nil } var output strings.Builder if c > 0 { output.WriteString(fmt.Sprintf("%d errors while stopping containers", c)) } if i > 0 { output.WriteString(fmt.Sprintf("%d errors while cleaning up images", c)) } return errors.New(output.String()) } func awaitDockerClient() { log.Debug("Sleeping for a second to ensure the docker api client has been properly initialized.") time.Sleep(1 * time.Second) }