feature: add step check root device step in chrrot builder

builder/osc/chroot/builder.go

@@ -225,6 +225,19 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 		&StepVmInfo{},
 	}
 
+	if !b.config.FromScratch {
+		steps = append(steps,
+			&osccommon.StepSourceOMIInfo{
+				SourceOmi:                b.config.SourceOMI,
+				EnableOMISriovNetSupport: b.config.OMISriovNetSupport,
+				EnableOMIENASupport:      b.config.OMIENASupport,
+				OmiFilters:               b.config.SourceOMIFilter,
+				OMIVirtType:              b.config.OMIVirtType,
+			},
+			&StepCheckRootDevice{},
+		)
+	}
+
 	// Run!
 	b.runner = common.NewRunner(steps, b.config.PackerConfig, ui)
 	b.runner.Run(state)

builder/osc/chroot/step_check_root_device.go

@@ -0,0 +1,32 @@
+package chroot
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/hashicorp/packer/helper/multistep"
+	"github.com/hashicorp/packer/packer"
+	"github.com/outscale/osc-go/oapi"
+)
+
+// StepCheckRootDevice makes sure the root device on the AMI is EBS-backed.
+type StepCheckRootDevice struct{}
+
+func (s *StepCheckRootDevice) Run(_ context.Context, state multistep.StateBag) multistep.StepAction {
+	image := state.Get("source_image").(oapi.Image)
+	ui := state.Get("ui").(packer.Ui)
+
+	ui.Say("Checking the root device on source AMI...")
+
+	// It must be EBS-backed otherwise the build won't work
+	if image.RootDeviceType != "ebs" {
+		err := fmt.Errorf("The root device of the source AMI must be EBS-backed.")
+		state.Put("error", err)
+		ui.Error(err.Error())
+		return multistep.ActionHalt
+	}
+
+	return multistep.ActionContinue
+}
+
+func (s *StepCheckRootDevice) Cleanup(multistep.StateBag) {}