WIP Add experimental pack cmd

cmd/ubuntu-image/main.go

@@ -41,6 +41,11 @@ func executeStateMachine(commonOpts *commands.CommonOpts, stateMachineOpts *comm
 		stateMachine.Args = ubuntuImageCommand.Classic.ClassicArgsPassed
 		stateMachine.SetCommonOpts(commonOpts, stateMachineOpts)
 		stateMachineInterface = stateMachine
+	} else if imageType == "pack" {
+		stateMachine := new(statemachine.PackStateMachine)
+		stateMachine.Opts = ubuntuImageCommand.Pack.PackOptsPassed
+		stateMachine.SetCommonOpts(commonOpts, stateMachineOpts)
+		stateMachineInterface = stateMachine
 	}
 
 	// set up, run, and tear down the state machine

internal/commands/common.go

@@ -34,4 +34,7 @@ type UbuntuImageCommand struct {
 		ClassicArgsPassed ClassicArgs `positional-args:"true" required:"false"`
 		ClassicOptsPassed ClassicOpts
 	} `command:"classic"`
+	Pack struct {
+		PackOptsPassed PackOpts `required:"true"`
+	} `command:"pack" hidden:"true"`
 }

internal/commands/pack.go

@@ -0,0 +1,8 @@
+package commands
+
+// PackOpts holds all flags that are specific to the pack command
+type PackOpts struct {
+	ArtifactType string `long:"artifact-type" description:"Type of the resulting disk image file." required:"true" hidden:"true" default:"img"`
+	GadgetDir string `long:"gadget-dir" description:"Directory containing the gadget.yaml and the gadget tree." required:"true" hidden:"true"`
+	RootfsDir string `long:"rootfs-dir" description:"Directory containing the rootfs" required:"true" hidden:"true"`
+}

internal/statemachine/pack.go

@@ -0,0 +1,46 @@
+package statemachine
+
+import (
+	"fmt"
+
+	"github.com/canonical/ubuntu-image/internal/commands"
+)
+
+var packStates = []stateFunc{
+	{"prepare_pack", (*StateMachine).preparePack},
+	{"load_gadget_yaml", (*StateMachine).loadGadgetYaml},
+	{"calculate_rootfs_size", (*StateMachine).calculateRootfsSize},
+	{"populate_bootfs_contents", (*StateMachine).populateBootfsContents},
+	{"populate_prepare_partitions", (*StateMachine).populatePreparePartitions},
+	{"make_disk", (*StateMachine).makeDisk},
+	{"update_bootloader", (*StateMachine).updateBootloader},
+}
+
+// PackStateMachine embeds StateMachine and adds the command line flags specific to pack images
+type PackStateMachine struct {
+	StateMachine
+	Opts commands.PackOpts
+}
+
+// Setup assigns variables and calls other functions that must be executed before Run()
+func (packStateMachine *PackStateMachine) Setup() error {
+	fmt.Printf("WARNING: this is an experimental feature.")
+
+	// set the parent pointer of the embedded struct
+	packStateMachine.parent = packStateMachine
+
+	// set the beginning states that will be used by all pack image builds
+	packStateMachine.states = packStates
+
+	// do the validation common to all image types
+	if err := packStateMachine.validateInput(); err != nil {
+		return err
+	}
+
+	// if --resume was passed, figure out where to start
+	if err := packStateMachine.readMetadata(metadataStateFile); err != nil {
+		return err
+	}
+
+	return nil
+}

internal/statemachine/pack_states.go

@@ -0,0 +1,12 @@
+package statemachine
+
+import "path/filepath"
+
+func (stateMachine *StateMachine) preparePack() error {
+	packStateMachine := stateMachine.parent.(*PackStateMachine)
+
+	packStateMachine.YamlFilePath = filepath.Join(packStateMachine.Opts.GadgetDir, "meta", "gadget.yaml")
+
+
+	return nil
+}