Deprecate "devicemapper" storage driver, and add warning

thaJeztah · thaJeztah · commit 06fcabbaa0d4 · 2018-10-11T15:46:26.000+02:00
The `devicemapper` storage driver is deprecated in favor of `overlay2`, and will
be removed in a future release. Users of the `devicemapper` storage driver are
recommended to migrate to a different storage driver, such as `overlay2`, which
is now the default storage driver.

The `devicemapper` storage driver facilitates running Docker on older (3.x) kernels
that have no support for other storage drivers (such as overlay2, or AUFS).

Now that support for `overlay2` is added to all supported distros (as they are
either on kernel 4.x, or have support for multiple lowerdirs backported), there
is no reason to continue maintenance of the `devicemapper` storage driver.

Signed-off-by: Sebastiaan van Stijn &lt;github@gone.nl&gt;
diff --git a/daemon/graphdriver/driver.go b/daemon/graphdriver/driver.go
@@ -195,6 +195,7 @@ type Options struct {
 func New(name string, pg plugingetter.PluginGetter, config Options) (Driver, error) {
 	if name != "" {
 		logrus.Debugf("[graphdriver] trying provided driver: %s", name) // so the logs show specified driver
+		logDeprecatedWarning(name)
 		return GetDriver(name, pg, config)
 	}
 
@@ -232,6 +233,7 @@ func New(name string, pg plugingetter.PluginGetter, config Options) (Driver, err
 			}
 
 			logrus.Infof("[graphdriver] using prior storage driver: %s", name)
+			logDeprecatedWarning(name)
 			return driver, nil
 		}
 	}
@@ -245,6 +247,7 @@ func New(name string, pg plugingetter.PluginGetter, config Options) (Driver, err
 			}
 			return nil, err
 		}
+		logDeprecatedWarning(name)
 		return driver, nil
 	}
 
@@ -257,6 +260,7 @@ func New(name string, pg plugingetter.PluginGetter, config Options) (Driver, err
 			}
 			return nil, err
 		}
+		logDeprecatedWarning(name)
 		return driver, nil
 	}
 	return nil, fmt.Errorf("No supported storage backend found")
@@ -305,3 +309,20 @@ func isEmptyDir(name string) bool {
 	}
 	return false
 }
+
+// isDeprecated checks if a storage-driver is marked "deprecated"
+func isDeprecated(name string) bool {
+	switch name {
+	// NOTE: when deprecating a driver, update daemon.fillDriverInfo() accordingly
+	case "devicemapper":
+		return true
+	}
+	return false
+}
+
+// logDeprecatedWarning logs a warning if the given storage-driver is marked "deprecated"
+func logDeprecatedWarning(name string) {
+	if isDeprecated(name) {
+		logrus.Warnf("[graphdriver] WARNING: the %s storage-driver is deprecated, and will be removed in a future release", name)
+	}
+}
diff --git a/daemon/info.go b/daemon/info.go
@@ -131,6 +131,10 @@ func (daemon *Daemon) fillDriverInfo(v *types.Info) {
 		if len(daemon.graphDrivers) > 1 {
 			drivers += fmt.Sprintf(" (%s) ", os)
 		}
+		switch gd {
+		case "devicemapper":
+			v.Warnings = append(v.Warnings, fmt.Sprintf("WARNING: the %s storage-driver is deprecated, and will be removed in a future release.", gd))
+		}
 	}
 	drivers = strings.TrimSpace(drivers)
 

Original file line number	Diff line number	Diff line change
`@@ -195,6 +195,7 @@ type Options struct {`
`195`	`195`	`func New(name string, pg plugingetter.PluginGetter, config Options) (Driver, error) {`
`196`	`196`	`if name != "" {`
`197`	`197`	`logrus.Debugf("[graphdriver] trying provided driver: %s", name) // so the logs show specified driver`
	`198`	`+ logDeprecatedWarning(name)`
`198`	`199`	`return GetDriver(name, pg, config)`
`199`	`200`	`}`
`200`	`201`
`@@ -232,6 +233,7 @@ func New(name string, pg plugingetter.PluginGetter, config Options) (Driver, err`
`232`	`233`	`}`
`233`	`234`
`234`	`235`	`logrus.Infof("[graphdriver] using prior storage driver: %s", name)`
	`236`	`+ logDeprecatedWarning(name)`
`235`	`237`	`return driver, nil`
`236`	`238`	`}`
`237`	`239`	`}`
`@@ -245,6 +247,7 @@ func New(name string, pg plugingetter.PluginGetter, config Options) (Driver, err`
`245`	`247`	`}`
`246`	`248`	`return nil, err`
`247`	`249`	`}`
	`250`	`+ logDeprecatedWarning(name)`
`248`	`251`	`return driver, nil`
`249`	`252`	`}`
`250`	`253`
`@@ -257,6 +260,7 @@ func New(name string, pg plugingetter.PluginGetter, config Options) (Driver, err`
`257`	`260`	`}`
`258`	`261`	`return nil, err`
`259`	`262`	`}`
	`263`	`+ logDeprecatedWarning(name)`
`260`	`264`	`return driver, nil`
`261`	`265`	`}`
`262`	`266`	`return nil, fmt.Errorf("No supported storage backend found")`
`@@ -305,3 +309,20 @@ func isEmptyDir(name string) bool {`
`305`	`309`	`}`
`306`	`310`	`return false`
`307`	`311`	`}`
	`312`	`+`
	`313`	`+// isDeprecated checks if a storage-driver is marked "deprecated"`
	`314`	`+func isDeprecated(name string) bool {`
	`315`	`+ switch name {`
	`316`	`+ // NOTE: when deprecating a driver, update daemon.fillDriverInfo() accordingly`
	`317`	`+ case "devicemapper":`
	`318`	`+ return true`
	`319`	`+ }`
	`320`	`+ return false`
	`321`	`+}`
	`322`	`+`
	`323`	`+// logDeprecatedWarning logs a warning if the given storage-driver is marked "deprecated"`
	`324`	`+func logDeprecatedWarning(name string) {`
	`325`	`+ if isDeprecated(name) {`
	`326`	`+ logrus.Warnf("[graphdriver] WARNING: the %s storage-driver is deprecated, and will be removed in a future release", name)`
	`327`	`+ }`
	`328`	`+}`
Original file line number	Diff line number	Diff line change
`@@ -131,6 +131,10 @@ func (daemon Daemon) fillDriverInfo(v types.Info) {`
`131`	`131`	`if len(daemon.graphDrivers) > 1 {`
`132`	`132`	`drivers += fmt.Sprintf(" (%s) ", os)`
`133`	`133`	`}`
	`134`	`+ switch gd {`
	`135`	`+ case "devicemapper":`
	`136`	`+ v.Warnings = append(v.Warnings, fmt.Sprintf("WARNING: the %s storage-driver is deprecated, and will be removed in a future release.", gd))`
	`137`	`+ }`
`134`	`138`	`}`
`135`	`139`	`drivers = strings.TrimSpace(drivers)`
`136`	`140`