moby/daemon/reload.go
Lukas Heeren ce61a1ed98
Adding ability to change max download attempts
Moby works perfectly when you are in a situation when one has a good and stable
internet connection. Operating in area's where internet connectivity is likely
to be lost in undetermined intervals, like a satellite connection or 4G/LTE in
rural area's, can become a problem when pulling a new image. When connection is
lost while image layers are being pulled, Moby will try to reconnect up to 5 times.
If this fails, the incompletely downloaded layers are lost will need to be completely
downloaded again during the next pull request. This means that we are using more
data than we might have to.

Pulling a layer multiple times from the start can become costly over a satellite
or 4G/LTE connection. As these techniques (especially 4G) quite common in IoT and
Moby is used to run Azure IoT Edge devices, I would like to add a settable maximum
download attempts. The maximum download attempts is currently set at 5
(distribution/xfer/download.go). I would like to change this constant to a variable
that the user can set. The default will still be 5, so nothing will change from
the current version unless specified when starting the daemon with the added flag
or in the config file.

I added a default value of 5 for DefaultMaxDownloadAttempts and a settable
max-download-attempts in the daemon config file. It is also added to the config
of dockerd so it can be set with a flag when starting the daemon. This value gets
stored in the imageService of the daemon when it is initiated and can be passed
to the NewLayerDownloadManager as a parameter. It will be stored in the
LayerDownloadManager when initiated. This enables us to set the max amount of
retries in makeDownoadFunc equal to the max download attempts.

I also added some tests that are based on maxConcurrentDownloads/maxConcurrentUploads.

You can pull this version and test in a development container. Either create a config
`file /etc/docker/daemon.json` with `{"max-download-attempts"=3}``, or use
`dockerd --max-download-attempts=3 -D &` to start up the dockerd. Start downloading
a container and disconnect from the internet whilst downloading. The result would
be that it stops pulling after three attempts.

Signed-off-by: Lukas Heeren <lukas-heeren@hotmail.com>
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2019-09-19 13:51:40 +02:00

361 lines
13 KiB
Go

package daemon // import "github.com/docker/docker/daemon"
import (
"encoding/json"
"fmt"
"github.com/docker/docker/daemon/config"
"github.com/docker/docker/daemon/discovery"
"github.com/sirupsen/logrus"
)
// Reload reads configuration changes and modifies the
// daemon according to those changes.
// These are the settings that Reload changes:
// - Platform runtime
// - Daemon debug log level
// - Daemon max concurrent downloads
// - Daemon max concurrent uploads
// - Daemon max download attempts
// - Daemon shutdown timeout (in seconds)
// - Cluster discovery (reconfigure and restart)
// - Daemon labels
// - Insecure registries
// - Registry mirrors
// - Daemon live restore
func (daemon *Daemon) Reload(conf *config.Config) (err error) {
daemon.configStore.Lock()
attributes := map[string]string{}
defer func() {
jsonString, _ := json.Marshal(daemon.configStore)
// we're unlocking here, because
// LogDaemonEventWithAttributes() -> SystemInfo() -> GetAllRuntimes()
// holds that lock too.
daemon.configStore.Unlock()
if err == nil {
logrus.Infof("Reloaded configuration: %s", jsonString)
daemon.LogDaemonEventWithAttributes("reload", attributes)
}
}()
if err := daemon.reloadPlatform(conf, attributes); err != nil {
return err
}
daemon.reloadDebug(conf, attributes)
daemon.reloadMaxConcurrentDownloadsAndUploads(conf, attributes)
if err := daemon.reloadMaxDownloadAttempts(conf, attributes); err != nil {
return err
}
daemon.reloadShutdownTimeout(conf, attributes)
daemon.reloadFeatures(conf, attributes)
if err := daemon.reloadClusterDiscovery(conf, attributes); err != nil {
return err
}
if err := daemon.reloadLabels(conf, attributes); err != nil {
return err
}
if err := daemon.reloadAllowNondistributableArtifacts(conf, attributes); err != nil {
return err
}
if err := daemon.reloadInsecureRegistries(conf, attributes); err != nil {
return err
}
if err := daemon.reloadRegistryMirrors(conf, attributes); err != nil {
return err
}
if err := daemon.reloadLiveRestore(conf, attributes); err != nil {
return err
}
return daemon.reloadNetworkDiagnosticPort(conf, attributes)
}
// reloadDebug updates configuration with Debug option
// and updates the passed attributes
func (daemon *Daemon) reloadDebug(conf *config.Config, attributes map[string]string) {
// update corresponding configuration
if conf.IsValueSet("debug") {
daemon.configStore.Debug = conf.Debug
}
// prepare reload event attributes with updatable configurations
attributes["debug"] = fmt.Sprintf("%t", daemon.configStore.Debug)
}
// reloadMaxConcurrentDownloadsAndUploads updates configuration with max concurrent
// download and upload options and updates the passed attributes
func (daemon *Daemon) reloadMaxConcurrentDownloadsAndUploads(conf *config.Config, attributes map[string]string) {
// If no value is set for max-concurrent-downloads we assume it is the default value
// We always "reset" as the cost is lightweight and easy to maintain.
maxConcurrentDownloads := config.DefaultMaxConcurrentDownloads
if conf.IsValueSet("max-concurrent-downloads") && conf.MaxConcurrentDownloads != nil {
maxConcurrentDownloads = *conf.MaxConcurrentDownloads
}
daemon.configStore.MaxConcurrentDownloads = &maxConcurrentDownloads
logrus.Debugf("Reset Max Concurrent Downloads: %d", *daemon.configStore.MaxConcurrentDownloads)
// If no value is set for max-concurrent-upload we assume it is the default value
// We always "reset" as the cost is lightweight and easy to maintain.
maxConcurrentUploads := config.DefaultMaxConcurrentUploads
if conf.IsValueSet("max-concurrent-uploads") && conf.MaxConcurrentUploads != nil {
maxConcurrentUploads = *conf.MaxConcurrentUploads
}
daemon.configStore.MaxConcurrentUploads = &maxConcurrentUploads
logrus.Debugf("Reset Max Concurrent Uploads: %d", *daemon.configStore.MaxConcurrentUploads)
if daemon.imageService != nil {
daemon.imageService.UpdateConfig(&maxConcurrentDownloads, &maxConcurrentUploads)
}
// prepare reload event attributes with updatable configurations
attributes["max-concurrent-downloads"] = fmt.Sprintf("%d", *daemon.configStore.MaxConcurrentDownloads)
// prepare reload event attributes with updatable configurations
attributes["max-concurrent-uploads"] = fmt.Sprintf("%d", *daemon.configStore.MaxConcurrentUploads)
}
// reloadMaxDownloadAttempts updates configuration with max concurrent
// download attempts when a connection is lost and updates the passed attributes
func (daemon *Daemon) reloadMaxDownloadAttempts(conf *config.Config, attributes map[string]string) error {
if err := config.ValidateMaxDownloadAttempts(conf); err != nil {
return err
}
// If no value is set for max-download-attempts we assume it is the default value
// We always "reset" as the cost is lightweight and easy to maintain.
maxDownloadAttempts := config.DefaultDownloadAttempts
if conf.IsValueSet("max-download-attempts") && conf.MaxDownloadAttempts != nil {
maxDownloadAttempts = *conf.MaxDownloadAttempts
}
daemon.configStore.MaxDownloadAttempts = &maxDownloadAttempts
logrus.Debugf("Reset Max Download Attempts: %d", *daemon.configStore.MaxDownloadAttempts)
// prepare reload event attributes with updatable configurations
attributes["max-download-attempts"] = fmt.Sprintf("%d", *daemon.configStore.MaxDownloadAttempts)
return nil
}
// reloadShutdownTimeout updates configuration with daemon shutdown timeout option
// and updates the passed attributes
func (daemon *Daemon) reloadShutdownTimeout(conf *config.Config, attributes map[string]string) {
// update corresponding configuration
if conf.IsValueSet("shutdown-timeout") {
daemon.configStore.ShutdownTimeout = conf.ShutdownTimeout
logrus.Debugf("Reset Shutdown Timeout: %d", daemon.configStore.ShutdownTimeout)
}
// prepare reload event attributes with updatable configurations
attributes["shutdown-timeout"] = fmt.Sprintf("%d", daemon.configStore.ShutdownTimeout)
}
// reloadClusterDiscovery updates configuration with cluster discovery options
// and updates the passed attributes
func (daemon *Daemon) reloadClusterDiscovery(conf *config.Config, attributes map[string]string) (err error) {
defer func() {
// prepare reload event attributes with updatable configurations
attributes["cluster-store"] = conf.ClusterStore
attributes["cluster-advertise"] = conf.ClusterAdvertise
attributes["cluster-store-opts"] = "{}"
if daemon.configStore.ClusterOpts != nil {
opts, err2 := json.Marshal(conf.ClusterOpts)
if err != nil {
err = err2
}
attributes["cluster-store-opts"] = string(opts)
}
}()
newAdvertise := conf.ClusterAdvertise
newClusterStore := daemon.configStore.ClusterStore
if conf.IsValueSet("cluster-advertise") {
if conf.IsValueSet("cluster-store") {
newClusterStore = conf.ClusterStore
}
newAdvertise, err = config.ParseClusterAdvertiseSettings(newClusterStore, conf.ClusterAdvertise)
if err != nil && err != discovery.ErrDiscoveryDisabled {
return err
}
}
if daemon.clusterProvider != nil {
if err := conf.IsSwarmCompatible(); err != nil {
return err
}
}
// check discovery modifications
if !config.ModifiedDiscoverySettings(daemon.configStore, newClusterStore, newAdvertise, conf.ClusterOpts) {
return nil
}
// enable discovery for the first time if it was not previously enabled
if daemon.discoveryWatcher == nil {
discoveryWatcher, err := discovery.Init(newClusterStore, newAdvertise, conf.ClusterOpts)
if err != nil {
return fmt.Errorf("failed to initialize discovery: %v", err)
}
daemon.discoveryWatcher = discoveryWatcher
} else if err == discovery.ErrDiscoveryDisabled {
// disable discovery if it was previously enabled and it's disabled now
daemon.discoveryWatcher.Stop()
} else if err = daemon.discoveryWatcher.Reload(conf.ClusterStore, newAdvertise, conf.ClusterOpts); err != nil {
// reload discovery
return err
}
daemon.configStore.ClusterStore = newClusterStore
daemon.configStore.ClusterOpts = conf.ClusterOpts
daemon.configStore.ClusterAdvertise = newAdvertise
if daemon.netController == nil {
return nil
}
netOptions, err := daemon.networkOptions(daemon.configStore, daemon.PluginStore, nil)
if err != nil {
logrus.WithError(err).Warn("failed to get options with network controller")
return nil
}
err = daemon.netController.ReloadConfiguration(netOptions...)
if err != nil {
logrus.Warnf("Failed to reload configuration with network controller: %v", err)
}
return nil
}
// reloadLabels updates configuration with engine labels
// and updates the passed attributes
func (daemon *Daemon) reloadLabels(conf *config.Config, attributes map[string]string) error {
// update corresponding configuration
if conf.IsValueSet("labels") {
daemon.configStore.Labels = conf.Labels
}
// prepare reload event attributes with updatable configurations
if daemon.configStore.Labels != nil {
labels, err := json.Marshal(daemon.configStore.Labels)
if err != nil {
return err
}
attributes["labels"] = string(labels)
} else {
attributes["labels"] = "[]"
}
return nil
}
// reloadAllowNondistributableArtifacts updates the configuration with allow-nondistributable-artifacts options
// and updates the passed attributes.
func (daemon *Daemon) reloadAllowNondistributableArtifacts(conf *config.Config, attributes map[string]string) error {
// Update corresponding configuration.
if conf.IsValueSet("allow-nondistributable-artifacts") {
daemon.configStore.AllowNondistributableArtifacts = conf.AllowNondistributableArtifacts
if err := daemon.RegistryService.LoadAllowNondistributableArtifacts(conf.AllowNondistributableArtifacts); err != nil {
return err
}
}
// Prepare reload event attributes with updatable configurations.
if daemon.configStore.AllowNondistributableArtifacts != nil {
v, err := json.Marshal(daemon.configStore.AllowNondistributableArtifacts)
if err != nil {
return err
}
attributes["allow-nondistributable-artifacts"] = string(v)
} else {
attributes["allow-nondistributable-artifacts"] = "[]"
}
return nil
}
// reloadInsecureRegistries updates configuration with insecure registry option
// and updates the passed attributes
func (daemon *Daemon) reloadInsecureRegistries(conf *config.Config, attributes map[string]string) error {
// update corresponding configuration
if conf.IsValueSet("insecure-registries") {
daemon.configStore.InsecureRegistries = conf.InsecureRegistries
if err := daemon.RegistryService.LoadInsecureRegistries(conf.InsecureRegistries); err != nil {
return err
}
}
// prepare reload event attributes with updatable configurations
if daemon.configStore.InsecureRegistries != nil {
insecureRegistries, err := json.Marshal(daemon.configStore.InsecureRegistries)
if err != nil {
return err
}
attributes["insecure-registries"] = string(insecureRegistries)
} else {
attributes["insecure-registries"] = "[]"
}
return nil
}
// reloadRegistryMirrors updates configuration with registry mirror options
// and updates the passed attributes
func (daemon *Daemon) reloadRegistryMirrors(conf *config.Config, attributes map[string]string) error {
// update corresponding configuration
if conf.IsValueSet("registry-mirrors") {
daemon.configStore.Mirrors = conf.Mirrors
if err := daemon.RegistryService.LoadMirrors(conf.Mirrors); err != nil {
return err
}
}
// prepare reload event attributes with updatable configurations
if daemon.configStore.Mirrors != nil {
mirrors, err := json.Marshal(daemon.configStore.Mirrors)
if err != nil {
return err
}
attributes["registry-mirrors"] = string(mirrors)
} else {
attributes["registry-mirrors"] = "[]"
}
return nil
}
// reloadLiveRestore updates configuration with live restore option
// and updates the passed attributes
func (daemon *Daemon) reloadLiveRestore(conf *config.Config, attributes map[string]string) error {
// update corresponding configuration
if conf.IsValueSet("live-restore") {
daemon.configStore.LiveRestoreEnabled = conf.LiveRestoreEnabled
}
// prepare reload event attributes with updatable configurations
attributes["live-restore"] = fmt.Sprintf("%t", daemon.configStore.LiveRestoreEnabled)
return nil
}
// reloadNetworkDiagnosticPort updates the network controller starting the diagnostic if the config is valid
func (daemon *Daemon) reloadNetworkDiagnosticPort(conf *config.Config, attributes map[string]string) error {
if conf == nil || daemon.netController == nil || !conf.IsValueSet("network-diagnostic-port") ||
conf.NetworkDiagnosticPort < 1 || conf.NetworkDiagnosticPort > 65535 {
// If there is no config make sure that the diagnostic is off
if daemon.netController != nil {
daemon.netController.StopDiagnostic()
}
return nil
}
// Enable the network diagnostic if the flag is set with a valid port within the range
logrus.WithFields(logrus.Fields{"port": conf.NetworkDiagnosticPort, "ip": "127.0.0.1"}).Warn("Starting network diagnostic server")
daemon.netController.StartDiagnostic(conf.NetworkDiagnosticPort)
return nil
}
// reloadFeatures updates configuration with enabled/disabled features
func (daemon *Daemon) reloadFeatures(conf *config.Config, attributes map[string]string) {
// update corresponding configuration
// note that we allow features option to be entirely unset
daemon.configStore.Features = conf.Features
// prepare reload event attributes with updatable configurations
attributes["features"] = fmt.Sprintf("%v", daemon.configStore.Features)
}