Containers: capture conversion logs

Store the conversion log to a file (captured-output.txt) in the
container and when in development mode, have its output displayed on the
terminal output.

dangerzone/conversion/doc_to_pixels.py

@@ -377,12 +377,16 @@ async def main() -> int:
 
     try:
         await converter.convert()
+        error_code = 0  # Success!
     except (RuntimeError, TimeoutError, ValueError) as e:
         converter.update_progress(str(e), error=True)
-        return 1
+        error_code = 1
-    else:
-        return 0  # Success!
 
+    if not running_on_qubes():
+        # Write debug information (containers version)
+        with open("/tmp/dangerzone/captured_output.txt", "wb") as container_log:
+            container_log.write(converter.captured_output)
+    return error_code
 
 if __name__ == "__main__":
     sys.exit(asyncio.run(main()))

dangerzone/isolation_provider/base.py

@@ -10,6 +10,8 @@ from ..util import replace_control_chars
 
 log = logging.getLogger(__name__)
 
+MAX_CONVERSION_LOG_CHARS = 150 * 50  # up to ~150 lines of 50 characters
+
 
 class IsolationProvider(ABC):
     """

dangerzone/isolation_provider/container.py

@@ -7,17 +7,13 @@ import platform
 import shlex
 import shutil
 import subprocess
+import sys
 import tempfile
 from typing import Any, Callable, List, Optional, Tuple
 
 from ..document import Document
-from ..util import (
+from ..util import get_resource_path, get_subprocess_startupinfo, get_tmp_dir
-    get_resource_path,
+from .base import MAX_CONVERSION_LOG_CHARS, IsolationProvider
-    get_subprocess_startupinfo,
-    get_tmp_dir,
-    replace_control_chars,
-)
-from .base import IsolationProvider
 
 # Define startupinfo for subprocesses
 if platform.system() == "Windows":
@@ -288,6 +284,14 @@ class Container(IsolationProvider):
             f"ENABLE_TIMEOUTS={self.enable_timeouts}",
         ]
         ret = self.exec_container(document, command, extra_args)
+
+        if getattr(sys, "dangerzone_dev", False):
+            log_path = pixel_dir / "captured_output.txt"
+            with open(log_path, "r", encoding="ascii", errors="replace") as f:
+                log.info(
+                    f"Conversion output (doc to pixels):\n{f.read(MAX_CONVERSION_LOG_CHARS)}"
+                )
+
         if ret != 0:
             log.error("documents-to-pixels failed")
         else:

dangerzone/isolation_provider/qubes.py

@@ -22,14 +22,13 @@ log = logging.getLogger(__name__)
 from ..conversion.common import running_on_qubes
 from ..conversion.pixels_to_pdf import PixelsToPDF
 from ..util import get_resource_path, get_subprocess_startupinfo, get_tmp_dir
+from .base import MAX_CONVERSION_LOG_CHARS
 
 CONVERTED_FILE_PATH = (
     # FIXME won't work for parallel conversions (see #454)
     "/tmp/safe-output-compressed.pdf"
 )
 
-MAX_CONVERSION_LOG_CHARS = 150 * 50  # up to ~150 lines of 50 characters
-
 
 def read_bytes(p: subprocess.Popen, buff_size: int) -> bytes:
     """Read bytes from stdout."""