Add gzip support

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

src/pystack/__main__.py

@@ -1,9 +1,11 @@
 import argparse
+import gzip
 import logging
 import os
 import pathlib
 import signal
 import sys
+import tempfile
 from contextlib import suppress
 from textwrap import dedent
 from typing import Any
@@ -319,6 +321,19 @@ def process_core(parser: argparse.ArgumentParser, args: argparse.Namespace) -> N
     if not corefile.exists():
         parser.error(f"Core {corefile} does not exist")
 
+    temp_file = None
+    if corefile.suffix == ".gz":
+        temp_file = tempfile.NamedTemporaryFile(delete=False)
+        try:
+            with gzip.open(corefile, "rb") as fp:
+                while chunk := fp.read(4 * 1024 * 1024):
+                    temp_file.write(chunk)
+        except gzip.BadGzipFile:
+            parser.error(f"Core {corefile} is not a valid gzip file")
+        finally:
+            temp_file.close()
+        corefile = pathlib.Path(temp_file.name)
+
     if args.executable is None:
         corefile_analyzer = CoreFileAnalyzer(corefile)
         executable = pathlib.Path(corefile_analyzer.extract_executable())
@@ -380,6 +395,10 @@ def process_core(parser: argparse.ArgumentParser, args: argparse.Namespace) -> N
         native = args.native_mode != NativeReportingMode.OFF
         print_thread(thread, native)
 
+    # Delete temporary file created if corefile is a gzip.
+    if temp_file:
+        pathlib.Path(temp_file.name).unlink()
+
 
 if __name__ == "__main__":  # pragma: no cover
     main()

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
@@ -431,6 +432,56 @@ 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()]
+
+    # 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(
+        "gzip.open", mock_open(read_data=b"")
+    ) as gzip_open_mock, patch(
+        "tempfile.NamedTemporaryFile"
+    ) as tempfile_mock, patch(
+        "pystack.__main__.os.unlink", return_value=None
+    ), 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
+        tempfile_mock.return_value.name = Path("corefile.gz")
+
+        main()
+
+    # THEN
+
+    get_process_threads_mock.assert_called_with(
+        Path("corefile.gz"),
+        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