Merge pull request #150 from PyAr/better-error-report

Better error reporting when executing a subprocess.

fades/envbuilder.py

@@ -76,6 +76,9 @@ def create_with_virtualenv(self, interpreter, virtualenv_options):
             logger.error('Virtualenv is not installed. It is needed to create a virtualenv with '
                          'a different python version than fades (got {})'.format(error))
             exit()
+        except helpers.ExecutionError as error:
+            error.dump_to_log(logger)
+            exit()
         except Exception as error:
             logger.exception("Error creating virtualenv:  %s", error)
             exit()

fades/helpers.py

@@ -31,6 +31,23 @@
 print(json.dumps(d))
 """
 
+STDOUT_LOG_PREFIX = ":: "
+
+
+class ExecutionError(Exception):
+    """Execution of subprocess ended not in 0."""
+    def __init__(self, retcode, cmd, collected_stdout):
+        self._retcode = retcode
+        self._cmd = cmd
+        self._collected_stdout = collected_stdout
+        super().__init__()
+
+    def dump_to_log(self, logger):
+        """Send the cmd info and collected stdout to logger."""
+        logger.error("Execution ended in %s for cmd %s", self._retcode, self._cmd)
+        for line in self._collected_stdout:
+            logger.error(STDOUT_LOG_PREFIX + line)
+
 
 def logged_exec(cmd):
     """Execute a command, redirecting the output to the log."""
@@ -41,10 +58,10 @@ def logged_exec(cmd):
     for line in p.stdout:
         line = line[:-1].decode("utf8")
         stdout.append(line)
-        logger.debug(":: " + line)
+        logger.debug(STDOUT_LOG_PREFIX + line)
     retcode = p.wait()
     if retcode:
-        raise subprocess.CalledProcessError(retcode, cmd)
+        raise ExecutionError(retcode, cmd, stdout)
     return stdout
 
 

fades/pipmanager.py

@@ -56,6 +56,9 @@ def install(self, dependency):
         logger.info("Installing dependency: %s", str_dep)
         try:
             helpers.logged_exec(args)
+        except helpers.ExecutionError as error:
+            error.dump_to_log(logger)
+            exit()
         except Exception as error:
             logger.exception("Error installing %s: %s", str_dep, error)
             exit()