(feat): Big overhaul of layer and actions

cmd/ebs-bootstrap.go

@@ -55,17 +55,16 @@ func main() {
 	})
 	checkError(bv.Validate(c))
 	// Layers
-	layers := layer.NewExponentialBackoffLayerExecutor([]layer.Layer{
+	le := layer.NewExponentialBackoffLayerExecutor([]layer.Layer{
 		layer.NewFormatDeviceLayer(db),
 		layer.NewLabelDeviceLayer(db),
-		layer.NewUnmountDeviceLayer(db, fb),
 		layer.NewCreateDirectoryLayer(db, fb),
 		layer.NewMountDeviceLayer(db, fb),
 		layer.NewResizeDeviceLayer(drb),
 		layer.NewChangeOwnerLayer(ub, fb),
 		layer.NewChangePermissionsLayer(fb),
 	}, ae)
-	checkError(layers.Execute(c))
+	checkError(le.Execute(c))
 }
 
 func checkError(err error) {

configs/ubuntu.yml

@@ -2,11 +2,11 @@ defaults:
   mode: healthcheck
 devices:
   /dev/vdb:
-    fs: ext4
+    fs: xfs
     label: lasith-rules
-    mountPoint: /ifmx/dev/james
+    mountPoint: /ifmx/tempp
     mountOptions: defaults
     group: ubuntu
     user: ubuntu
-    permissions: 644
+    permissions: 0644
     resizeFs: true

internal/action/action.go

@@ -9,18 +9,12 @@ import (
 	"github.com/reecetech/ebs-bootstrap/internal/utils"
 )
 
-const (
-	DisabledWarning     = ""
-	FormatActionWarning = "Formatting larger disks can take several seconds ⌛ Please wait patiently 🙇"
-)
-
 type Action interface {
 	Execute() error
 	GetDeviceName() string
 	Success() string
 	Prompt() string
 	Refuse() string
-	Warning() string
 }
 
 type ActionExecutor struct {
@@ -53,9 +47,6 @@ func (ae *ActionExecutor) ExecuteAction(action Action) error {
 }
 
 func (ae *ActionExecutor) executeAction(action Action) error {
-	if w := action.Warning(); w != DisabledWarning {
-		log.Printf("🟠 %s: %s", action.GetDeviceName(), w)
-	}
 	if err := action.Execute(); err != nil {
 		return err
 	}
@@ -64,8 +55,8 @@ func (ae *ActionExecutor) executeAction(action Action) error {
 }
 
 func (ae *ActionExecutor) ExecuteActions(actions []Action) error {
-	for _, action := range actions {
-		err := ae.ExecuteAction(action)
+	for _, a := range actions {
+		err := ae.ExecuteAction(a)
 		if err != nil {
 			return err
 		}

internal/action/file.go

@@ -44,10 +44,6 @@ func (a *CreateDirectoryAction) Success() string {
 	return fmt.Sprintf("Successfully created directory %s", a.path)
 }
 
-func (a *CreateDirectoryAction) Warning() string {
-	return DisabledWarning
-}
-
 type ChangeOwnerAction struct {
 	deviceName string
 	path       string
@@ -84,10 +80,6 @@ func (a *ChangeOwnerAction) Success() string {
 	return fmt.Sprintf("Successfully changed ownership (%d:%d) of %s", a.uid, a.gid, a.path)
 }
 
-func (a *ChangeOwnerAction) Warning() string {
-	return DisabledWarning
-}
-
 type ChangePermissionsAction struct {
 	deviceName string
 	path       string
@@ -129,7 +121,3 @@ func (a *ChangePermissionsAction) Refuse() string {
 func (a *ChangePermissionsAction) Success() string {
 	return fmt.Sprintf("Successfully change permissions of %s to %s", a.path, a.perms)
 }
-
-func (a *ChangePermissionsAction) Warning() string {
-	return DisabledWarning
-}

internal/action/format.go

@@ -37,7 +37,3 @@ func (a *FormatDeviceAction) Refuse() string {
 func (a *FormatDeviceAction) Success() string {
 	return fmt.Sprintf("Successfully formated to %s", a.fileSystemService.GetFileSystem())
 }
-
-func (a *FormatDeviceAction) Warning() string {
-	return FormatActionWarning
-}

internal/action/label.go

@@ -39,7 +39,3 @@ func (a *LabelDeviceAction) Refuse() string {
 func (a *LabelDeviceAction) Success() string {
 	return fmt.Sprintf("Successfully labelled to %s", a.label)
 }
-
-func (a *LabelDeviceAction) Warning() string {
-	return DisabledWarning
-}

internal/action/mount.go

@@ -46,10 +46,6 @@ func (a *MountDeviceAction) Success() string {
 	return fmt.Sprintf("Successfully mounted %s to %s (%s)", a.source, a.target, a.options)
 }
 
-func (a *MountDeviceAction) Warning() string {
-	return DisabledWarning
-}
-
 type UnmountDeviceAction struct {
 	source        string
 	target        string
@@ -87,7 +83,3 @@ func (a *UnmountDeviceAction) Refuse() string {
 func (a *UnmountDeviceAction) Success() string {
 	return fmt.Sprintf("Successfully unmounted %s from %s", a.source, a.target)
 }
-
-func (a *UnmountDeviceAction) Warning() string {
-	return DisabledWarning
-}

internal/backend/device.go

@@ -11,7 +11,7 @@ import (
 
 type DeviceBackend interface {
 	GetBlockDevice(device string) (*model.BlockDevice, error)
-	Label(bd *model.BlockDevice, label string) (action.Action, error)
+	Label(bd *model.BlockDevice, label string) ([]action.Action, error)
 	Format(bd *model.BlockDevice, fileSystem model.FileSystem) (action.Action, error)
 	Mount(bd *model.BlockDevice, target string, options model.MountOptions) action.Action
 	Remount(bd *model.BlockDevice, target string, options model.MountOptions) action.Action
@@ -41,26 +41,35 @@ func (db *LinuxDeviceBackend) GetBlockDevice(device string) (*model.BlockDevice,
 	return blockDevice, nil
 }
 
-func (db *LinuxDeviceBackend) Label(bd *model.BlockDevice, label string) (action.Action, error) {
-	fs, err := db.fileSystemServiceFactory.Select(bd.FileSystem)
+// This method is unique in the sense that some file-systems like xfs might require
+// that the device be unmounted before any labelling operations can commence. For these
+// file systems, we would preprend any label action with an unmount action (if the device is already mounted)
+func (db *LinuxDeviceBackend) Label(bd *model.BlockDevice, label string) ([]action.Action, error) {
+	actions := make([]action.Action, 0)
+	fss, err := db.fileSystemServiceFactory.Select(bd.FileSystem)
 	if err != nil {
 		return nil, err
 	}
-	return action.NewLabelDeviceAction(
+	if fss.DoesLabelRequireUnmount() && bd.MountPoint != "" {
+		a := db.Umount(bd)
+		actions = append(actions, a)
+	}
+	a := action.NewLabelDeviceAction(
 		bd.Name,
 		label,
-		fs,
-	), nil
+		fss,
+	)
+	return append(actions, a), nil
 }
 
 func (db *LinuxDeviceBackend) Format(bd *model.BlockDevice, fileSystem model.FileSystem) (action.Action, error) {
-	fs, err := db.fileSystemServiceFactory.Select(fileSystem)
+	fss, err := db.fileSystemServiceFactory.Select(fileSystem)
 	if err != nil {
 		return nil, err
 	}
 	return action.NewFormatDeviceAction(
 		bd.Name,
-		fs,
+		fss,
 	), nil
 }
 

internal/backend/resize.go

@@ -59,7 +59,7 @@ func (dmb *LinuxDeviceResizeBackend) Resize(bd *model.BlockDevice) (action.Actio
 		return nil, err
 	}
 	target := bd.Name
-	if fss.DoesResizeRequiresMount() {
+	if fss.DoesResizeRequireMount() {
 		if bd.MountPoint == "" {
 			return nil, fmt.Errorf("🔴 %s: To resize the %s file system, device must be mounted", fss.GetFileSystem(), bd.Name)
 		}
@@ -87,7 +87,11 @@ func (dmb *LinuxDeviceResizeBackend) From(config *config.Config) error {
 			return err
 		}
 		// Can not fetch file system metrics from a device with
-		// no file system. Therefore, we continue if this is the case
+		// no file system. Therefore, we exit with error if this is the case
+		// The reason we exit early, rather than continuing is because we want
+		// to simplify the data view of the Device Resize Backend as much as possible
+		// With this check, we ensure that all devices in the resize backend have a
+		// valid file system
 		if bd.FileSystem == model.Unformatted {
 			return fmt.Errorf("🔴 %s: Can not resize a device with no file system", bd.Name)
 		}

internal/layer/directory.go

@@ -50,8 +50,8 @@ func (fdl *CreateDirectoryLayer) Modify(c *config.Config) ([]action.Action, erro
 		if d != nil {
 			continue
 		}
-		action := fdl.fileBackend.CreateDirectory(bd.Name, cd.MountPoint)
-		actions = append(actions, action)
+		a := fdl.fileBackend.CreateDirectory(bd.Name, cd.MountPoint)
+		actions = append(actions, a)
 	}
 	return actions, nil
 }
@@ -68,3 +68,7 @@ func (fdl *CreateDirectoryLayer) Validate(c *config.Config) error {
 	log.Println("🟢 Passed directory validation checks")
 	return nil
 }
+
+func (fdl *CreateDirectoryLayer) Warning() string {
+	return DisableWarning
+}

internal/layer/format.go

@@ -34,12 +34,12 @@ func (fdl *FormatDeviceLayer) Modify(c *config.Config) ([]action.Action, error)
 		if bd.FileSystem == cd.Fs {
 			continue
 		}
+		if cd.Fs == model.Unformatted {
+			return nil, fmt.Errorf("🔴 %s: Can not erase the file system of a device", bd.Name)
+		}
 		if bd.FileSystem != model.Unformatted {
 			return nil, fmt.Errorf("🔴 %s: Can not format a device that already has a %s file system", bd.Name, bd.FileSystem)
 		}
-		if bd.MountPoint != "" {
-			return nil, fmt.Errorf("🔴 %s: Can not format a device that is already mounted to %s", bd.Name, bd.MountPoint)
-		}
 		action, err := fdl.deviceBackend.Format(bd, cd.Fs)
 		if err != nil {
 			return nil, err
@@ -62,3 +62,7 @@ func (fdl *FormatDeviceLayer) Validate(c *config.Config) error {
 	log.Println("🟢 Passed file system validation checks")
 	return nil
 }
+
+func (fdl *FormatDeviceLayer) Warning() string {
+	return "Formatting larger disks can take several seconds ⌛"
+}

internal/layer/label.go

@@ -40,11 +40,11 @@ func (fdl *LabelDeviceLayer) Modify(c *config.Config) ([]action.Action, error) {
 		if bd.FileSystem == model.Unformatted {
 			return nil, fmt.Errorf("🔴 %s: Can not label a device with no file system", bd.Name)
 		}
-		action, err := fdl.deviceBackend.Label(bd, cd.Label)
+		a, err := fdl.deviceBackend.Label(bd, cd.Label)
 		if err != nil {
 			return nil, err
 		}
-		actions = append(actions, action)
+		actions = append(actions, a...)
 	}
 	return actions, nil
 }
@@ -65,3 +65,7 @@ func (fdl *LabelDeviceLayer) Validate(c *config.Config) error {
 	log.Println("🟢 Passed label validation checks")
 	return nil
 }
+
+func (fdl *LabelDeviceLayer) Warning() string {
+	return "Certain file systems require that devices be unmounted prior to labeling"
+}

internal/layer/layer.go

@@ -1,6 +1,7 @@
 package layer
 
 import (
+	"log"
 	"math"
 	"time"
 
@@ -15,10 +16,15 @@ const (
 	MaxRetries      = 3
 )
 
+const (
+	DisableWarning = ""
+)
+
 type Layer interface {
 	From(config *config.Config) error
 	Modify(c *config.Config) ([]action.Action, error)
 	Validate(config *config.Config) error
+	Warning() string
 }
 
 type LayerExecutor interface {
@@ -58,6 +64,11 @@ func (le *ExponentialBackoffLayerExecutor) Execute(config *config.Config) error
 		if err != nil {
 			return err
 		}
+		// Only print warning if actions are detected and a valid warning
+		// message is provided
+		if warning := layer.Warning(); len(actions) > 0 && warning != DisableWarning {
+			log.Printf("🟠 %s", warning)
+		}
 		err = le.actionExecutor.ExecuteActions(actions)
 		if err != nil {
 			return err

internal/layer/mount.go

@@ -7,6 +7,7 @@ import (
 	"github.com/reecetech/ebs-bootstrap/internal/action"
 	"github.com/reecetech/ebs-bootstrap/internal/backend"
 	"github.com/reecetech/ebs-bootstrap/internal/config"
+	"github.com/reecetech/ebs-bootstrap/internal/model"
 )
 
 type MountDeviceLayer struct {
@@ -39,16 +40,14 @@ func (fdl *MountDeviceLayer) Modify(c *config.Config) ([]action.Action, error) {
 		if cd.MountPoint == "" {
 			continue
 		}
-		if bd.MountPoint != "" && bd.MountPoint != cd.MountPoint {
-			return nil, fmt.Errorf("🔴 %s: Device is already mounted to %s. Thus cannot be mounted to %s", name, bd.MountPoint, cd.MountPoint)
+		if bd.FileSystem == model.Unformatted {
+			return nil, fmt.Errorf("🔴 %s: Can not mount a device with no file system", bd.Name)
 		}
-
-		var a action.Action
 		if bd.MountPoint == cd.MountPoint {
-			if !c.GetRemount(name) {
-				continue
+			if c.GetRemount(name) {
+				a := fdl.deviceBackend.Remount(bd, cd.MountPoint, cd.MountOptions)
+				actions = append(actions, a)
 			}
-			a = fdl.deviceBackend.Remount(bd, cd.MountPoint, cd.MountOptions)
 		} else {
 			_, err = fdl.fileBackend.GetDirectory(cd.MountPoint)
 			if err != nil {
@@ -60,10 +59,14 @@ func (fdl *MountDeviceLayer) Modify(c *config.Config) ([]action.Action, error) {
 			if fdl.fileBackend.IsMount(cd.MountPoint) {
 				return nil, fmt.Errorf("🔴 %s: %s is already mounted by another device", name, cd.MountPoint)
 			}
-			a = fdl.deviceBackend.Mount(bd, cd.MountPoint, cd.MountOptions)
+			// If mount point already exists, then lets unmount it first
+			if bd.MountPoint != "" {
+				a := fdl.deviceBackend.Umount(bd)
+				actions = append(actions, a)
+			}
+			a := fdl.deviceBackend.Mount(bd, cd.MountPoint, cd.MountOptions)
+			actions = append(actions, a)
 		}
-
-		actions = append(actions, a)
 	}
 	return actions, nil
 }
@@ -84,3 +87,7 @@ func (fdl *MountDeviceLayer) Validate(c *config.Config) error {
 	log.Printf("🟢 Passed mountpoint validation checks")
 	return nil
 }
+
+func (fdl *MountDeviceLayer) Warning() string {
+	return "Devices mounted to a location not specified in the configuration will be unmounted"
+}

internal/layer/owner.go

@@ -68,8 +68,8 @@ func (fdl *ChangeOwnerLayer) Modify(c *config.Config) ([]action.Action, error) {
 		if d.Uid == uid && d.Gid == gid {
 			continue
 		}
-		action := fdl.fileBackend.ChangeOwner(name, cd.MountPoint, uid, gid)
-		actions = append(actions, action)
+		a := fdl.fileBackend.ChangeOwner(name, cd.MountPoint, uid, gid)
+		actions = append(actions, a)
 	}
 	return actions, nil
 }
@@ -119,3 +119,7 @@ func (fdl *ChangeOwnerLayer) Validate(c *config.Config) error {
 	log.Printf("🟢 Passed ownership validation checks")
 	return nil
 }
+
+func (fdl *ChangeOwnerLayer) Warning() string {
+	return DisableWarning
+}