stages/squashfs: Add exclude_paths support

Add the ability to exclude files and directories from the squashfs
image. This uses the mksquashfs -regex -e FILES... feature, so simple
matches or regexes can be used.

This also adds a new test for squashfs, based on the existing test for
erofs.

stages/org.osbuild.squashfs

@@ -10,6 +10,7 @@ def main(inputs, output_dir, options):
     source = inputs["tree"]["path"]
     filename = options["filename"].lstrip("/")
     compression = options.get("compression")
+    exclude_paths = options.get("exclude_paths")
 
     target = os.path.join(output_dir, filename)
 
@@ -22,6 +23,10 @@ def main(inputs, output_dir, options):
         for opt, val in opts.items():
             cmd += [f"-X{opt}", val]
 
+    if exclude_paths:
+        cmd += ["-regex", "-e"]
+        cmd.extend(exclude_paths)
+
     subprocess.run(cmd, check=True)
 
     return 0

stages/org.osbuild.squashfs.meta.json

@@ -14,6 +14,13 @@
           "description": "Filename for squashfs image",
           "type": "string"
         },
+        "exclude_paths": {
+          "type": "array",
+          "description": "Regex of paths to exclude, can be files or directories",
+          "items": {
+            "type": "string"
+          }
+        },
         "compression": {
           "type": "object",
           "additionalProperties": false,

stages/test/test_squashfs.py

@@ -0,0 +1,104 @@
+#!/usr/bin/python3
+
+import os.path
+import subprocess
+from unittest import mock
+
+import pytest
+
+from osbuild import testutil
+from osbuild.testutil import has_executable, make_fake_input_tree
+
+TEST_INPUT = [
+    ({}, []),
+    ({"compression": {"method": "lz4"}}, ["-comp", "lz4"]),
+    ({"compression": {"method": "xz", "options": {"bcj": "x86"}}}, ["-comp", "xz", "-Xbcj", "x86"]),
+    ({"exclude_paths": ["boot/.*", "root/.*"]}, ["-regex", "-e", "boot/.*", "root/.*"])
+]
+
+
+STAGE_NAME = "org.osbuild.squashfs"
+
+
+@pytest.mark.skipif(not has_executable("mksquashfs"), reason="no mksquashfs")
+@pytest.mark.parametrize("test_options,expected", TEST_INPUT)
+def test_squashfs_integration(tmp_path, stage_module, test_options, expected):  # pylint: disable=unused-argument
+    fake_input_tree = make_fake_input_tree(tmp_path, {
+        "/file-in-root.txt": "other content",
+        "/subdir/file-in-subdir.txt": "subdir content",
+    })
+    inputs = {
+        "tree": {
+            "path": fake_input_tree,
+        }
+    }
+    filename = "some-file.img"
+    options = {
+        "filename": filename,
+    }
+    options.update(test_options)
+
+    stage_module.main(inputs, tmp_path, options)
+
+    img_path = os.path.join(tmp_path, "some-file.img")
+    assert os.path.exists(img_path)
+    # validate the content
+    output = subprocess.check_output([
+        "unsquashfs", "-ls", img_path], encoding="utf-8")
+    assert "subdir/file-in-subdir.txt\n" in output
+    assert "file-in-root.txt\n" in output
+
+
+@mock.patch("subprocess.run")
+@pytest.mark.parametrize("test_options,expected", TEST_INPUT)
+def test_squashfs(mock_run, tmp_path, stage_module, test_options, expected):
+    fake_input_tree = make_fake_input_tree(tmp_path, {
+        "/some-dir/some-file.txt": "content",
+    })
+    inputs = {
+        "tree": {
+            "path": fake_input_tree,
+        }
+    }
+    filename = "some-file.img"
+    options = {
+        "filename": filename,
+    }
+    options.update(test_options)
+
+    stage_module.main(inputs, tmp_path, options)
+
+    expected = [
+        "mksquashfs",
+        f"{fake_input_tree}",
+        f"{os.path.join(tmp_path, filename)}",
+    ] + expected
+    mock_run.assert_called_with(expected, check=True)
+
+
+@pytest.mark.parametrize("test_data,expected_err", [
+    # bad
+    ({"extra": "option"}, "'extra' was unexpected"),
+    ({"compression": {"method": "invalid"}}, "'invalid' is not one of ["),
+    ({"compression": {}}, "'method' is a required property"),
+    ({"compression": {"method": "xz", "options": {"bcj": "invalid"}}}, "'invalid' is not one of ["),
+    ({"compression": {"method": "xz", "options": {"level": 9}}}, "Additional properties are not allowed"),
+    # good
+    ({"compression": {"method": "lz4"}}, ""),
+    ({"exclude_paths": ["boot/", "root/"]}, "")
+])
+def test_schema_validation_squashfs(stage_schema, test_data, expected_err):
+    test_input = {
+        "type": STAGE_NAME,
+        "options": {
+            "filename": "some-filename.img",
+        }
+    }
+    test_input["options"].update(test_data)
+    res = stage_schema.validate(test_input)
+
+    if expected_err == "":
+        assert res.valid is True, f"err: {[e.as_dict() for e in res.errors]}"
+    else:
+        assert res.valid is False
+        testutil.assert_jsonschema_error_contains(res, expected_err, expected_num_errs=1)