fix: allow packing a directory (#4794)

This fixes a regression in snapcraft 8.2 where `snapcraft pack
<directory>` stopped working.

Signed-off-by: Callahan Kovacs <callahan.kovacs@canonical.com>

snapcraft/application.py

@@ -256,7 +256,7 @@ def create_app() -> Snapcraft:
             craft_app_commands.lifecycle.BuildCommand,
             craft_app_commands.lifecycle.StageCommand,
             craft_app_commands.lifecycle.PrimeCommand,
-            craft_app_commands.lifecycle.PackCommand,
+            commands.PackCommand,
             commands.SnapCommand,  # Hidden (legacy compatibility)
             commands.RemoteBuildCommand,
             unimplemented.Plugins,

snapcraft/commands/__init__.py

@@ -37,7 +37,7 @@
     StoreLegacyUploadMetadataCommand,
     StoreLegacyValidateCommand,
 )
-from .lifecycle import SnapCommand
+from .lifecycle import PackCommand, SnapCommand
 from .manage import StoreCloseCommand, StoreReleaseCommand
 from .names import (
     StoreLegacyListCommand,
@@ -60,6 +60,7 @@
     "ExpandExtensions",
     "ListExtensions",
     "RemoteBuildCommand",
+    "PackCommand",
     "SnapCommand",
     "StoreCloseCommand",
     "StoreEditValidationSetsCommand",

snapcraft/commands/lifecycle.py

@@ -17,16 +17,107 @@
 """Snapcraft lifecycle commands."""
 
 import argparse
+import pathlib
+import textwrap
 from typing import Any
 
 import craft_application.commands
 from craft_cli import emit
 from typing_extensions import override
 
-# pylint: disable=too-many-ancestors
+import snapcraft.pack
 
 
-class SnapCommand(craft_application.commands.lifecycle.PackCommand):
+class PackCommand(craft_application.commands.LifecycleCommand):
+    """Snapcraft pack command."""
+
+    name = "pack"
+    help_msg = "Create the final artifact"
+    overview = textwrap.dedent(
+        """
+        Process parts and create a snap file containing the project payload
+        with the provided metadata. If a directory is specified, pack its
+        contents instead.
+        """
+    )
+
+    @override
+    def _fill_parser(self, parser: argparse.ArgumentParser) -> None:
+        """Add arguments specific to the pack command."""
+        super()._fill_parser(parser)
+
+        parser.add_argument(
+            "directory",
+            metavar="directory",
+            type=str,
+            nargs="?",
+            default=None,
+            help="Directory to pack",
+        )
+        parser.add_argument(
+            "--output",
+            "-o",
+            type=pathlib.Path,
+            default=pathlib.Path(),
+            help="Output directory for created packages",
+        )
+
+    @override
+    def _run(
+        self,
+        parsed_args: argparse.Namespace,
+        step_name: str | None = None,
+        **kwargs: Any,
+    ) -> None:
+        """Pack a directory or run the lifecycle and pack all artifacts."""
+        if parsed_args.directory:
+            emit.progress("Packing...")
+            snap_filename = snapcraft.pack.pack_snap(
+                parsed_args.directory, output=str(parsed_args.output)
+            )
+            emit.message(f"Packed {snap_filename}")
+        else:
+            super()._run(parsed_args, step_name="prime")
+            self._services.package.update_project()
+            self._services.package.write_metadata(self._services.lifecycle.prime_dir)
+
+            emit.progress("Packing...")
+            packages = self._services.package.pack(
+                self._services.lifecycle.prime_dir, parsed_args.output
+            )
+
+            if not packages:
+                emit.progress("No packages created.", permanent=True)
+            elif len(packages) == 1:
+                emit.progress(f"Packed {packages[0].name}", permanent=True)
+            else:
+                package_names = ", ".join(pkg.name for pkg in packages)
+                emit.progress(f"Packed: {package_names}", permanent=True)
+
+    @override
+    def needs_project(self, parsed_args: argparse.Namespace) -> bool:
+        """Project is not required to pack a directory."""
+        if parsed_args.directory:
+            emit.debug("Not loading project because a directory was provided.")
+            return False
+
+        emit.debug("Loading project because a directory was not provided.")
+        return True
+
+    @override
+    def run_managed(self, parsed_args: argparse.Namespace) -> bool:
+        """Return whether the command should run in managed mode or not.
+
+        Packing a directory always runs locally.
+        """
+        if parsed_args.directory:
+            emit.debug("Not running managed mode because a directory was provided.")
+            return False
+
+        return super().run_managed(parsed_args)
+
+
+class SnapCommand(PackCommand):
     """Deprecated legacy command to pack the final snap payload."""
 
     name = "snap"

tests/spread/core22/packing/task.yaml

@@ -4,6 +4,9 @@ environment:
   CMD/pack: pack
   CMD/pack_output: pack -o output.snap
   CMD/pack_output_subdir: pack --output subdir/output.snap
+  CMD/pack_directory: pack prime
+  CMD/pack_directory_output: pack prime --output output.snap
+  CMD/pack_directory_output_subdir: pack prime --output subdir/output.snap
   CMD/snap: snap
   CMD/snap_output: snap --output output.snap
   CMD/snap_output_subdir: snap -o subdir/output.snap
@@ -25,6 +28,11 @@ restore: |
   restore_yaml "snap/snapcraft.yaml"
 
 execute: |
+  # create a local directory to pack
+  if [[ "$SPREAD_VARIANT" =~ "pack_directory" ]]; then
+    snapcraft prime --destructive-mode
+  fi
+  
   # shellcheck disable=SC2086
   snapcraft $CMD --destructive-mode
 

tests/spread/core24/packing/task.yaml

@@ -4,6 +4,9 @@ environment:
   CMD/pack: pack
   CMD/pack_output: pack -o output.snap
   CMD/pack_output_subdir: pack --output subdir/output.snap
+  CMD/pack_directory: pack prime
+  CMD/pack_directory_output: pack prime --output output.snap
+  CMD/pack_directory_output_subdir: pack prime --output subdir/output.snap
   CMD/snap: snap
   CMD/snap_output: snap --output output.snap
   CMD/snap_output_subdir: snap -o subdir/output.snap
@@ -17,14 +20,25 @@ prepare: |
   # set_base "$SNAP_DIR/snap/snapcraft.yaml"
 
 restore: |
-  snapcraft clean
   rm -Rf subdir ./*.snap
+  
+  # 'pack_directory' tests are run in destructive-mode
+  if [[ "$SPREAD_VARIANT" =~ "pack_directory" ]]; then
+    snapcraft clean --destructive-mode
+  else
+    snapcraft clean
+  fi
 
   #shellcheck source=tests/spread/tools/snapcraft-yaml.sh
   . "$TOOLS_DIR/snapcraft-yaml.sh"
   restore_yaml "snap/snapcraft.yaml"
 
 execute: |
+  # create a local directory to pack
+  if [[ "$SPREAD_VARIANT" =~ "pack_directory" ]]; then
+    snapcraft prime --destructive-mode
+  fi
+  
   # shellcheck disable=SC2086
   snapcraft $CMD
 

tests/unit/commands/test_lifecycle.py

@@ -95,7 +95,7 @@ def test_core22_pack_command_with_directory(mocker):
 def test_snap_command_fallback(tmp_path, emitter, mocker, fake_services):
     """Test that the snap command is falling back to the pack command."""
     parsed_args = argparse.Namespace(parts=[], output=tmp_path)
-    mock_pack = mocker.patch("craft_application.commands.lifecycle.PackCommand._run")
+    mock_pack = mocker.patch("snapcraft.commands.lifecycle.PackCommand._run")
     cmd = lifecycle.SnapCommand({"app": APP_METADATA, "services": fake_services})
     cmd.run(parsed_args=parsed_args)
     mock_pack.assert_called_once()

tests/unit/test_application.py

@@ -23,11 +23,11 @@
 import pytest
 import yaml
 from craft_application import util
-from craft_application.commands.lifecycle import PackCommand
 from craft_parts.packages import snaps
 from craft_providers import bases
 
 from snapcraft import application, services
+from snapcraft.commands import PackCommand
 from snapcraft.errors import ClassicFallback, SnapcraftError
 from snapcraft.models.project import Architecture
 from snapcraft.parts.yaml_utils import CURRENT_BASES, ESM_BASES, LEGACY_BASES