Add gzip support (#171)

Add support for Gzip compressed corefiles

docs/corefile.rst

@@ -37,6 +37,8 @@ In most cases, you just need to provide the location of the core to use PyStack
         (Python) File "/test.py", line 16, in third_func
             time.sleep(1000)
 
+Pystack can automatically extract core dumps from `.gz` files: `pystack core ./archived_core_file.gz`
+
 To learn more about the different options you can use to customize what is reported, check the :ref:`customizing-the-reports` section.
 
 Providing the executable

news/add_gzip_support.rst

@@ -0,0 +1,4 @@
+Features
+~~~~~~~~
+
+- Add support for Gzip compressed corefiles (#171)

src/pystack/__main__.py

@@ -13,7 +13,9 @@
 from typing import Set
 
 from pystack.errors import InvalidPythonProcess
+from pystack.process import decompress_gzip
 from pystack.process import is_elf
+from pystack.process import is_gzip
 
 from . import errors
 from . import print_thread
@@ -319,6 +321,9 @@ def process_core(parser: argparse.ArgumentParser, args: argparse.Namespace) -> N
     if not corefile.exists():
         parser.error(f"Core {corefile} does not exist")
 
+    if is_gzip(corefile):
+        corefile = decompress_gzip(corefile)
+
     if args.executable is None:
         corefile_analyzer = CoreFileAnalyzer(corefile)
         executable = pathlib.Path(corefile_analyzer.extract_executable())

src/pystack/process.py

@@ -1,7 +1,9 @@
+import gzip
 import logging
 import pathlib
 import re
 import subprocess
+import tempfile
 from typing import Optional
 from typing import Tuple
 
@@ -129,3 +131,43 @@ def get_thread_name(pid: int, tid: int) -> Optional[str]:
             return comm.read().strip()
     except OSError:
         return None
+
+
+def is_gzip(filename: pathlib.Path) -> bool:
+    """
+    Checks if the given file is a Gzip file based on the header.
+
+    Args:
+        filename (pathlib.Path): The path to the file to be checked.
+
+    Returns:
+        bool: True if the file starts with the Gzip header, False otherwise.
+    """
+    gzip_header = b"\x1f\x8b"
+    with open(filename, "rb") as thefile:
+        return thefile.read(2) == gzip_header
+
+
+def decompress_gzip(
+    filename: pathlib.Path, chunk_size: int = 4 * 1024 * 1024
+) -> pathlib.Path:
+    """Decompresses a Gzip file and writes the contents to a temporary file.
+
+    Args:
+        filename: The path to the gzip file to decompress.
+        chunk_size: Size of chunks to read and write at a time; defaults to 4MB.
+
+    Returns:
+        The path to the temporary file containing the decompressed data.
+
+    Raises:
+        gzip.BadGzipFile: If the file is not a valid gzip file.
+    """
+    with tempfile.NamedTemporaryFile(delete=False) as temp_file:
+        with gzip.open(filename, "rb") as file_handle:
+            while True:
+                chunk = file_handle.read(chunk_size)
+                if not chunk:
+                    break
+                temp_file.write(chunk)
+    return pathlib.Path(temp_file.name)

tests/unit/test_main.py

@@ -3,6 +3,7 @@
 from textwrap import dedent
 from unittest.mock import Mock
 from unittest.mock import call
+from unittest.mock import mock_open
 from unittest.mock import patch
 
 import pytest
@@ -409,6 +410,8 @@ def test_process_core_default_without_executable():
         "pathlib.Path.exists", return_value=True
     ), patch(
         "pystack.__main__.is_elf", return_value=True
+    ), patch(
+        "pystack.__main__.is_gzip", return_value=False
     ), patch(
         "pystack.__main__.CoreFileAnalyzer"
     ) as core_file_analizer_mock:
@@ -431,6 +434,61 @@ def test_process_core_default_without_executable():
     assert print_thread_mock.mock_calls == [call(thread, False) for thread in threads]
 
 
+def test_process_core_default_gzip_without_executable():
+    # GIVEN
+
+    argv = ["pystack", "core", "corefile.gz"]
+
+    threads = [Mock(), Mock(), Mock()]
+
+    temp_mock_file = Mock()
+    temp_mock_file.name = Path("/tmp/file")
+    temp_file_context_mock = Mock()
+    temp_file_context_mock.__enter__ = Mock(return_value=temp_mock_file)
+    temp_file_context_mock.__exit__ = Mock(return_value=None)
+
+    # WHEN
+
+    with patch(
+        "pystack.__main__.get_process_threads_for_core"
+    ) as get_process_threads_mock, patch(
+        "pystack.__main__.print_thread"
+    ) as print_thread_mock, patch(
+        "sys.argv", argv
+    ), patch(
+        "pathlib.Path.exists", return_value=True
+    ), patch(
+        "pystack.__main__.is_elf", return_value=True
+    ), patch(
+        "builtins.open", mock_open(read_data=b"\x1f\x8b")
+    ), patch(
+        "gzip.open", mock_open(read_data=b"")
+    ) as gzip_open_mock, patch(
+        "tempfile.NamedTemporaryFile", return_value=temp_file_context_mock
+    ), patch(
+        "pystack.__main__.CoreFileAnalyzer"
+    ) as core_file_analizer_mock:
+        core_file_analizer_mock().extract_executable.return_value = (
+            "extracted_executable"
+        )
+        get_process_threads_mock.return_value = threads
+
+        main()
+
+    # THEN
+
+    get_process_threads_mock.assert_called_with(
+        Path("/tmp/file"),
+        Path("extracted_executable"),
+        library_search_path="",
+        native_mode=NativeReportingMode.OFF,
+        locals=False,
+        method=StackMethod.AUTO,
+    )
+    assert print_thread_mock.mock_calls == [call(thread, False) for thread in threads]
+    gzip_open_mock.assert_called_with(Path("corefile.gz"), "rb")
+
+
 def test_process_core_default_without_executable_and_executable_does_not_exist(capsys):
     # GIVEN
 
@@ -440,7 +498,7 @@ def test_process_core_default_without_executable_and_executable_does_not_exist(c
 
     with patch("sys.argv", argv), patch(
         "pathlib.Path.exists"
-    ) as path_exists_mock, patch(
+    ) as path_exists_mock, patch("pystack.__main__.is_gzip", return_value=False), patch(
         "pystack.__main__.CoreFileAnalyzer"
     ) as core_file_analizer_mock:
         core_file_analizer_mock().extract_executable.return_value = (
@@ -473,6 +531,8 @@ def test_process_core_executable_not_elf_file(capsys):
         "pystack.__main__.CoreFileAnalyzer"
     ), patch(
         "pystack.__main__.is_elf", return_value=False
+    ), patch(
+        "pystack.__main__.is_gzip", return_value=False
     ):
         get_process_threads_mock.return_value = threads
         with pytest.raises(SystemExit):
@@ -503,6 +563,8 @@ def test_process_core_default_with_executable():
         "pystack.__main__.CoreFileAnalyzer"
     ), patch(
         "pystack.__main__.is_elf", return_value=True
+    ), patch(
+        "pystack.__main__.is_gzip", return_value=False
     ):
         get_process_threads_mock.return_value = threads
         main()
@@ -548,6 +610,8 @@ def test_process_core_native(argument, mode):
         "pystack.__main__.CoreFileAnalyzer"
     ), patch(
         "pystack.__main__.is_elf", return_value=True
+    ), patch(
+        "pystack.__main__.is_gzip", return_value=False
     ):
         get_process_threads_mock.return_value = threads
         main()
@@ -586,6 +650,8 @@ def test_process_core_locals():
         "pystack.__main__.CoreFileAnalyzer"
     ), patch(
         "pystack.__main__.is_elf", return_value=True
+    ), patch(
+        "pystack.__main__.is_gzip", return_value=False
     ):
         get_process_threads_mock.return_value = threads
         main()
@@ -631,6 +697,8 @@ def test_process_core_with_search_path():
         "pystack.__main__.CoreFileAnalyzer"
     ), patch(
         "pystack.__main__.is_elf", return_value=True
+    ), patch(
+        "pystack.__main__.is_gzip", return_value=False
     ):
         get_process_threads_mock.return_value = threads
         main()
@@ -677,6 +745,8 @@ def test_process_core_with_search_root():
         return_value=True,
     ), patch(
         "pystack.__main__.is_elf", return_value=True
+    ), patch(
+        "pystack.__main__.is_gzip", return_value=False
     ):
         get_process_threads_mock.return_value = threads
         main()
@@ -785,6 +855,8 @@ def does_exit(what):
     ) as get_process_threads_mock, patch(
         "pystack.__main__.print_thread"
     ) as print_thread_mock, patch(
+        "pystack.__main__.is_gzip", return_value=False
+    ), patch(
         "sys.argv", argv
     ), patch.object(
         Path, "exists", does_exit
@@ -821,6 +893,8 @@ def test_process_core_error(exception, exval, capsys):
         "pystack.__main__.CoreFileAnalyzer"
     ), patch(
         "pystack.__main__.is_elf", return_value=True
+    ), patch(
+        "pystack.__main__.is_gzip", return_value=False
     ):
         # THEN
         get_process_threads_mock.side_effect = exception("Oh no!")
@@ -856,6 +930,8 @@ def test_process_core_exhaustive():
         "pystack.__main__.CoreFileAnalyzer"
     ), patch(
         "pystack.__main__.is_elf", return_value=True
+    ), patch(
+        "pystack.__main__.is_gzip", return_value=False
     ):
         get_process_threads_mock.return_value = threads
         main()
@@ -942,6 +1018,8 @@ def test_nocolor_output_at_the_front_for_core():
         "pystack.__main__.CoreFileAnalyzer"
     ), patch(
         "pystack.__main__.is_elf", return_value=True
+    ), patch(
+        "pystack.__main__.is_gzip", return_value=False
     ):
         main()
 
@@ -966,6 +1044,8 @@ def test_global_options_can_be_placed_at_any_point(option):
         "pystack.__main__.CoreFileAnalyzer"
     ), patch(
         "pystack.__main__.is_elf", return_value=True
+    ), patch(
+        "pystack.__main__.is_gzip", return_value=False
     ):
         # THEN
 
@@ -1131,6 +1211,8 @@ def test_process_core_does_not_crash_if_core_analyzer_fails(method):
     with patch("pystack.__main__.get_process_threads_for_core"), patch(
         "pystack.__main__.print_thread"
     ), patch("pystack.__main__.is_elf", return_value=True), patch(
+        "pystack.__main__.is_gzip", return_value=False
+    ), patch(
         "sys.argv", argv
     ), patch(
         "pathlib.Path.exists", return_value=True
@@ -1156,6 +1238,8 @@ def test_core_file_missing_modules_are_logged(caplog, native):
     with patch("pystack.__main__.get_process_threads_for_core"), patch(
         "pystack.__main__.print_thread"
     ), patch("pystack.__main__.is_elf", return_value=True), patch(
+        "pystack.__main__.is_gzip", return_value=False
+    ), patch(
         "sys.argv", argv
     ), patch(
         "pathlib.Path.exists", return_value=True
@@ -1187,6 +1271,8 @@ def test_core_file_missing_build_ids_are_logged(caplog, native):
     with patch("pystack.__main__.get_process_threads_for_core"), patch(
         "pystack.__main__.print_thread"
     ), patch("pystack.__main__.is_elf", return_value=True), patch(
+        "pystack.__main__.is_gzip", return_value=False
+    ), patch(
         "sys.argv", argv
     ), patch(
         "pathlib.Path.exists", return_value=True