Merge pull request #3556 from mulkieran/issue_project_650_b

Add script to get Stratis info from devicemapper path

.githooks/pre-commit

@@ -11,6 +11,7 @@ make fmt-ci &&
 	make clippy &&
 	make yamllint &&
 	make tmtlint &&
+	make pylint &&
 	make check-typos || exit 1
 
 export PYTHONPATH=$PWD/tests/client-dbus/src

.github/workflows/main.yml

@@ -54,6 +54,7 @@ jobs:
       - name: Install dependencies for Fedora
         run: >
           dnf install -y
+          black
           clang
           curl
           cryptsetup-devel
@@ -62,6 +63,7 @@ jobs:
           libblkid-devel
           make
           ncurses
+          python3-isort
           systemd-devel
       - uses: dtolnay/rust-toolchain@master
         with:
@@ -235,6 +237,21 @@ jobs:
       - name: Run shell check
         run: make -f Makefile fmt-shell-ci
 
+  pylint:
+    runs-on: ubuntu-22.04
+    container:
+      image: fedora:39  # CURRENT DEVELOPMENT ENVIRONMENT
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install dependencies
+        run: >
+          dnf install -y
+          make
+          pylint
+          python3-dbus
+      - name: Run pylint
+        run: make -f Makefile pylint
+
   python-based-tests:
     runs-on: ubuntu-22.04
     container:

.isort.cfg

@@ -0,0 +1,14 @@
+[settings]
+multi_line_output=3
+include_trailing_comma=True
+force_grid_wrap=0
+use_parentheses=True
+line_length=88
+
+sections = FUTURE,STDLIB,THIRDPARTY,FIRSTPARTY,LOCAL,LOCALFOLDER
+
+import_heading_future=isort: FUTURE
+import_heading_stdlib=isort: STDLIB
+import_heading_thirdparty=isort: THIRDPARTY
+import_heading_firstparty=isort: FIRSTPARTY
+import_heading_local=isort: LOCAL

Makefile

@@ -175,10 +175,14 @@ check-typos:
 ## Run cargo fmt
 fmt: fmt-macros
 	cargo fmt
+	isort ./src/bin/utils/stratis-decode-dm
+	black ./src/bin/utils/stratis-decode-dm
 
 ## Run cargo fmt for CI jobs
 fmt-ci: fmt-macros-ci
 	cargo fmt -- --check
+	isort --diff --check-only ./src/bin/utils/stratis-decode-dm
+	black ./src/bin/utils/stratis-decode-dm --check
 
 ## Run cargo fmt for stratisd_proc_macros
 fmt-macros:
@@ -333,6 +337,11 @@ install-systemd-cfg:
 	sed 's|@LIBEXECDIR@|$(LIBEXECDIR)|' systemd/stratisd-min-postinitrd.service.in > $(DESTDIR)$(UNITDIR)/stratisd-min-postinitrd.service
 	sed 's|@UNITEXECDIR@|$(UNITEXECDIR)|' systemd/[email protected] > $(DESTDIR)$(UNITDIR)/[email protected]
 
+## Install scripts
+install-scripts:
+	mkdir -p $(DESTDIR)$(BINDIR)
+	$(INSTALL) -Dpm0755 -t $(DESTDIR)$(BINDIR) src/bin/utils/stratis-decode-dm
+
 ## Install binaries
 install-binaries:
 	mkdir -p $(DESTDIR)$(BINDIR)
@@ -365,7 +374,7 @@ install-daemons:
 	$(INSTALL) -Dpm0755 -t $(DESTDIR)$(LIBEXECDIR) target/$(PROFILEDIR)/stratisd-min
 
 ## Install all stratisd files
-install: install-udev-cfg install-man-cfg install-dbus-cfg install-dracut-cfg install-systemd-cfg install-binaries install-udev-binaries install-fstab-script install-daemons
+install: install-udev-cfg install-man-cfg install-dbus-cfg install-dracut-cfg install-systemd-cfg install-scripts install-binaries install-udev-binaries install-fstab-script install-daemons
 
 ## Build all Rust artifacts
 build-all-rust: build build-min build-utils build-udev-utils stratisd-tools
@@ -504,6 +513,10 @@ clippy-no-ipc:
 clippy: clippy-macros clippy-min clippy-udev-utils clippy-no-ipc clippy-utils
 	RUSTFLAGS="${DENY}" cargo clippy ${CLIPPY_OPTS} -- ${CLIPPY_DENY} ${CLIPPY_PEDANTIC} ${CLIPPY_PEDANTIC_USELESS}
 
+## Lint Python parts of the source code
+pylint:
+	pylint --disable=invalid-name ./src/bin/utils/stratis-decode-dm
+
 .PHONY:
 	audit
 	audit-all-rust
@@ -541,10 +554,12 @@ clippy: clippy-macros clippy-min clippy-udev-utils clippy-no-ipc clippy-utils
 	install-dracut-cfg
 	install-fstab-script
 	install-man-cfg
+	install-scripts
 	install-systemd-cfg
 	install-udev-binaries
 	install-udev-cfg
 	license
+	pylint
 	test
 	test-valgrind
 	test-loop

src/bin/utils/stratis-decode-dm

@@ -0,0 +1,203 @@
+#!/usr/bin/env python3
+
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+"""
+Script to map from devicemapper name to Stratis values
+"""
+
+# isort: STDLIB
+import argparse
+import pathlib
+from enum import Enum
+from uuid import UUID
+
+# isort: THIRDPARTY
+import dbus
+
+_REVISION_NUMBER = 7
+_REVISION = f"r{_REVISION_NUMBER}"
+_BUS_NAME = "org.storage.stratis3"
+_TOP_OBJECT = "/org/storage/stratis3"
+_OBJECT_MANAGER = "org.freedesktop.DBus.ObjectManager"
+_TIMEOUT = 120000
+_POOL_IFACE = f"{_BUS_NAME}.pool.{_REVISION}"
+_FS_IFACE = f"{_BUS_NAME}.filesystem.{_REVISION}"
+_DEV_PATH = "/dev/stratis"
+
+
+class OutputMode(Enum):
+    """
+    Output mode choices.
+    """
+
+    FILESYSTEM_NAME = "filesystem-name"
+    POOL_NAME = "pool-name"
+    SYMLINK = "symlink"
+
+    def __str__(self):
+        return self.value
+
+
+def _parse_dm_name(dmname):
+    """
+    Parse a Stratis filesystem devicemapper name.
+
+    :param str dmname: the devicemapper name of the filesystem device
+    :returns: the pool and filesystem UUID
+    :rtype: UUID * UUID
+    """
+    try:
+        (stratis, format_version, pool_uuid, thin, fs, filesystem_uuid) = dmname.split(
+            "-"
+        )
+    except ValueError as err:
+        raise RuntimeError(
+            f"error parsing Stratis filesystem devicemapper name {dmname}"
+        ) from err
+
+    if stratis != "stratis" or format_version != "1" or thin != "thin" or fs != "fs":
+        raise RuntimeError(
+            f"error parsing Stratis filesystem devicemapper name {dmname}"
+        )
+
+    return (UUID(pool_uuid), UUID(filesystem_uuid))
+
+
+def _extract_dm_name(dmpath):
+    """
+    Extract the devicemapper name from the devicemapper path.
+
+    :param Path dmpath: The devicemapper path.
+    :returns: devicemapper name
+    :rtype: str
+    """
+
+    assert dmpath.is_absolute(), "parser ensures absolute path"
+
+    try:
+        (_, dev, mapper, name) = dmpath.parts
+    except ValueError as err:
+        raise RuntimeError(
+            f"error decomposing Stratis filesystem devicemapper path: {dmpath}"
+        ) from err
+
+    if dev != "dev" or mapper != "mapper":
+        raise RuntimeError(
+            f"error decomposing Stratis filesystem devicemapper path: {dmpath}"
+        )
+
+    return name
+
+
+def _get_managed_objects():
+    """
+    Get managed objects for stratis
+    :return: A dict,  Keys are object paths with dicts containing interface
+                      names mapped to property dicts.
+                      Property dicts map names to values.
+    """
+    object_manager = dbus.Interface(
+        dbus.SystemBus().get_object(_BUS_NAME, _TOP_OBJECT),
+        _OBJECT_MANAGER,
+    )
+    return object_manager.GetManagedObjects(timeout=_TIMEOUT)
+
+
+def _get_parser():
+    """
+    Build a parser for this script.
+    """
+
+    def _abs_path(path):
+        parsed_path = pathlib.Path(path)
+        if not parsed_path.is_absolute():
+            raise argparse.ArgumentTypeError(
+                f"{path} must be specified as an absolute path"
+            )
+
+        return parsed_path
+
+    parser = argparse.ArgumentParser(
+        description="Utility that maps from Stratis filesystem devicemapper path to a Stratis value"
+    )
+    parser.add_argument(
+        "path",
+        help="The absolute path of the devicemapper device ('/dev/mapper/<devicemapper-name>')",
+        metavar="PATH",
+        type=_abs_path,
+    )
+    parser.add_argument(
+        "--output",
+        choices=list(OutputMode),
+        help="Stratis value to print",
+        type=OutputMode,
+        required=True,
+    )
+    return parser
+
+
+def main():
+    """
+    The main method.
+    """
+    parser = _get_parser()
+    namespace = parser.parse_args()
+
+    dm_name = _extract_dm_name(namespace.path)
+
+    (pool_uuid, filesystem_uuid) = _parse_dm_name(dm_name)
+
+    managed_objects = _get_managed_objects()
+
+    (pool_uuid_str, filesystem_uuid_str) = (pool_uuid.hex, filesystem_uuid.hex)
+
+    pool_name = next(
+        (
+            obj_data[_POOL_IFACE]["Name"]
+            for obj_data in managed_objects.values()
+            if _POOL_IFACE in obj_data
+            and obj_data[_POOL_IFACE]["Uuid"] == pool_uuid_str
+        ),
+        None,
+    )
+
+    filesystem_name = next(
+        (
+            obj_data[_FS_IFACE]["Name"]
+            for obj_data in managed_objects.values()
+            if _FS_IFACE in obj_data
+            and obj_data[_FS_IFACE]["Uuid"] == filesystem_uuid_str
+        ),
+        None,
+    )
+
+    if namespace.output is OutputMode.SYMLINK:
+        if pool_name is None:
+            raise RuntimeError(
+                "Pool name could not be found; can not synthesize Stratis filesystem symlink"
+            )
+        if filesystem_name is None:
+            raise RuntimeError(
+                "Filesystem name could not be found; can not synthesize Stratis filesystem symlink"
+            )
+        print(pathlib.Path(_DEV_PATH, pool_name, filesystem_name))
+
+    elif namespace.output is OutputMode.FILESYSTEM_NAME:
+        if filesystem_name is None:
+            raise RuntimeError("Filesystem name could not be found")
+        print(filesystem_name)
+
+    elif namespace.output is OutputMode.POOL_NAME:
+        if filesystem_name is None:
+            raise RuntimeError("Pool name could not be found")
+        print(pool_name)
+
+    else:
+        assert False, "unreachable"
+
+
+if __name__ == "__main__":
+    main()