Add timeouts for exports

All three of the current exporters use a subprocess call to perform the
export. To prevent the process from hanging, we add a condition to kill
th process after a specified period of time.

mfr/core/utils.py

@@ -18,7 +18,7 @@ def make_provider(name, request, url):
             namespace='mfr.providers',
             name=name.lower(),
             invoke_on_load=True,
-            invoke_args=(request, url, ),
+            invoke_args=(request, url)
         ).driver
     except RuntimeError:
         raise exceptions.MakeProviderError(
@@ -49,7 +49,7 @@ def make_exporter(name, source_file_path, output_file_path, format):
             namespace='mfr.exporters',
             name=normalized_name,
             invoke_on_load=True,
-            invoke_args=(normalized_name, source_file_path, output_file_path, format),
+            invoke_args=(normalized_name, source_file_path, output_file_path, format)
         ).driver
     except RuntimeError:
         raise exceptions.MakeExporterError(

mfr/extensions/default/exporter.py

@@ -0,0 +1,5 @@
+from mfr.core.extension import BaseExporter
+
+class DefaultExporter(BaseExporter):
+    def export():
+        pass

mfr/extensions/jsc3d/export.py

@@ -1,13 +1,24 @@
-import os
+from os.path import (
+    basename,
+    splitext
+)
 import shutil
-import subprocess
+from subprocess import (
+    DEVNULL,
+    CalledProcessError,
+    TimeoutExpired,
+    check_call
+)
 from http import HTTPStatus
 from tempfile import NamedTemporaryFile
 
 from mfr.core import exceptions
 from mfr.core.extension import BaseExporter
-from mfr.extensions.jsc3d.settings import (FREECAD_BIN,
-                                           FREECAD_CONVERT_SCRIPT)
+from mfr.extensions.jsc3d.settings import (
+    FREECAD_BIN,
+    TIMEOUT,
+    CONVERSION_SCRIPT
+)
 
 
 class JSC3DExporter(BaseExporter):
@@ -22,16 +33,14 @@ def export(self):
                 temp_source_file.name = self.source_file_path + '.step'
                 shutil.copy2(self.source_file_path, temp_source_file.name)
 
-                subprocess.check_call([
-                    FREECAD_BIN,
-                    FREECAD_CONVERT_SCRIPT,
-                    temp_source_file.name,
-                    self.output_file_path,
-                    # silence output from freecadcmd
-                ], stdout=subprocess.DEVNULL)
+                check_call(
+                    [FREECAD_BIN, CONVERSION_SCRIPT, temp_source_file.name, self.output_file_path],
+                    stdout=DEVNULL,  # silence output from freecadcmd
+                    timeout=TIMEOUT
+                )
 
-        except subprocess.CalledProcessError as err:
-            name, extension = os.path.splitext(os.path.split(self.source_file_path)[-1])
+        except CalledProcessError as err:
+            name, extension = splitext(basename(self.source_file_path))
             raise exceptions.SubprocessError(
                 'Unable to export the file in the requested format, please try again later.',
                 process='freecad',
@@ -42,3 +51,18 @@ def export(self):
                 extension=extension or '',
                 exporter_class='jsc3d',
             )
+
+        except TimeoutExpired as err:
+            # The return code 52 is not re error code returned by the
+            # subprocess, but the error given to it by this waterbutler
+            # proccesss, for timing out.
+            raise exceptions.SubprocessError(
+                'JSC3D Conversion timed out.',
+                code=504,
+                process='freecad',
+                cmd=str(err.cmd),
+                returncode=52,
+                path=str(self.source_file_path),
+                extension=extension or '',
+                exporter_class='jsc3d'
+            )

mfr/extensions/jsc3d/settings.py

@@ -3,6 +3,7 @@
 config = settings.child('JSC3D_EXTENSION_CONFIG')
 
 FREECAD_BIN = config.get('FREECAD_BIN', '/usr/bin/freecadcmd')
-FREECAD_CONVERT_SCRIPT = config.get('FREECAD_CONVERT_SCRIPT', '/code/mfr/extensions/jsc3d/freecad_converter.py')
+CONVERSION_SCRIPT = config.get('FREECAD_CONVERT_SCRIPT', '/code/mfr/extensions/jsc3d/freecad_converter.py')
+TIMEOUT = int(config.get('FREECAD_TIMEOUT', 10))  # In seconds
 EXPORT_TYPE = config.get('EXPORT_TYPE', '.stl')
 EXPORT_EXCLUSIONS = config.get('EXPORT_EXCLUSIONS', '.3ds .stl .obj .ctm').split(' ')

mfr/extensions/tabular/settings.py

@@ -37,3 +37,4 @@
 })
 
 PSPP_CONVERT_BIN = config.get('PSPP_CONVERT_BIN', '/usr/bin/pspp-convert')
+PSPP_CONVERT_TIMEOUT = int(config.get('PSPP_CONVERT_TIMEOUT', 10))  # In seconds

mfr/extensions/tabular/utilities.py

@@ -1,10 +1,17 @@
 import re
-import subprocess
+from subprocess import (
+    CalledProcessError,
+    TimeoutExpired,
+    check_call
+)
 from tempfile import NamedTemporaryFile
 
-from mfr.core import exceptions
-from mfr.extensions.tabular import compat, settings
-
+from mfr.core.exceptions import SubprocessError
+from mfr.extensions.tabular import compat
+from mfr.extensions.tabular.settings import (
+    PSPP_CONVERT_BIN,
+    PSPP_CONVERT_TIMEOUT,
+)
 
 def header_population(headers):
     """make column headers from a list
@@ -48,13 +55,12 @@ def sav_to_csv(fp):
     """
     csv_file = NamedTemporaryFile(mode='w+b', suffix='.csv')
     try:
-        subprocess.check_call([
-            settings.PSPP_CONVERT_BIN,
-            fp.name,
-            csv_file.name,
-        ])
-    except subprocess.CalledProcessError as err:
-        raise exceptions.SubprocessError(
+        check_call(
+            [PSPP_CONVERT_BIN, fp.name, csv_file.name],
+            timeout=PSPP_CONVERT_TIMEOUT
+        )
+    except CalledProcessError as err:
+        raise SubprocessError(
             'Unable to convert the SPSS file to CSV, please try again later.',
             code=500,
             process='pspp',
@@ -64,4 +70,18 @@ def sav_to_csv(fp):
             extension='sav',
             exporter_class='tabular',
         )
+    except TimeoutExpired as err:
+        # The return code 52 is not the error code returned by the
+        # subprocess, but the error given to it by this waterbutler
+        # proccesss, for timing out.
+        raise SubprocessError(
+            'CSV Conversion timed out.',
+            code=504,
+            process='pspp',
+            cmd=str(err.cmd),
+            returncode=52,
+            path=fp.name,
+            extension='sav',
+            exporter_class='tabular'
+        )
     return csv_file

mfr/extensions/unoconv/export.py

@@ -1,28 +1,39 @@
-import os
-import subprocess
+from os.path import (
+    basename,
+    splitext
+)
+from subprocess import (
+    CalledProcessError,
+    run
+)
 
-from mfr.core import extension
-from mfr.core import exceptions
+from mfr.core.exceptions import SubprocessError
+from mfr.core.extension import BaseExporter
 
-from mfr.extensions.unoconv import settings
+from mfr.extensions.unoconv.settings import (
+    ADDRESS,
+    PORT,
+    UNOCONV_TIMEOUT,
+    UNOCONV_BIN
+)
 
 
-class UnoconvExporter(extension.BaseExporter):
+class UnoconvExporter(BaseExporter):
 
     def export(self):
         try:
-            subprocess.run([
-                settings.UNOCONV_BIN,
+            run([
+                UNOCONV_BIN,
                 '-n',
-                '-c', 'socket,host={},port={};urp;StarOffice.ComponentContext'.format(settings.ADDRESS, settings.PORT),
+                '-c', 'socket,host={},port={};urp;StarOffice.ComponentContext'.format(ADDRESS, PORT),
                 '-f', self.format,
                 '-o', self.output_file_path,
                 '-vvv',
                 self.source_file_path
-            ], check=True, timeout=settings.UNOCONV_TIMEOUT)
-        except subprocess.CalledProcessError as err:
-            name, extension = os.path.splitext(os.path.split(self.source_file_path)[-1])
-            raise exceptions.SubprocessError(
+            ], check=True, timeout=UNOCONV_TIMEOUT)
+        except CalledProcessError as err:
+            name, extension = splitext(basename(self.source_file_path))
+            raise SubprocessError(
                 'Unable to export the file in the requested format, please try again later.',
                 process='unoconv',
                 cmd=str(err.cmd),

mfr/server/handlers/export.py

@@ -76,6 +76,12 @@ async def get(self):
             self.source_file_path
         )
 
+        if self.metadata.ext == ".{}".format(self.format):
+            with open(self.source_file_path.full_path, 'rb') as fp:
+                self._set_headers()
+                await self.write_stream(waterbutler.core.streams.FileStreamReader(fp))
+            return
+
         exporter = utils.make_exporter(
             self.metadata.ext,
             self.source_file_path.full_path,