def exec(self, step: CodeStep, context: Dict,
store: FileSystemStorage) -> ExecResult:
"""Execute a workflow step of type :class:`flowserv.model.workflow.step.CodeStep`
in a given context.
Captures output to STDOUT and STDERR and includes them in the returned
execution result.
Note that the code worker expects a file system storage volume.
Parameters
----------
step: flowserv.model.workflow.step.CodeStep
Code step in a serial workflow.
context: dict
Context for the executed code.
store: flowserv.volume.fs.FileSystemStorage
Storage volume that contains the workflow run files.
Returns
-------
flowserv.controller.serial.workflow.result.ExecResult
"""
result = ExecResult(step=step)
out = sys.stdout
err = sys.stderr
sys.stdout = OutputStream(stream=result.stdout)
sys.stderr = OutputStream(stream=result.stderr)
# Change working directory temporarily.
cwd = os.getcwd()
os.chdir(store.basedir)
try:
step.exec(context=context)
except Exception as ex:
logging.error(ex, exc_info=True)
strace = '\n'.join(util.stacktrace(ex))
logging.debug(strace)
result.stderr.append(strace)
result.exception = ex
result.returncode = 1
finally:
# Make sure to reverse redirection of output streams
sys.stdout = out
sys.stderr = err
# Reset working directory.
os.chdir(cwd)
return result
def test_exec_func_step():
"""Test executing a Python function as a step in a serial workflow."""
args = {'x': 1, 'y': 2}
step = CodeStep(identifier='test', func=my_add, arg='z')
step.exec(context=args)
assert args == {'x': 1, 'y': 2, 'z': 3}
# Test renaming arguments.
step = CodeStep(identifier='test',
func=my_add,
varnames={'x': 'z'},
arg='x')
step.exec(context=args)
assert args == {'x': 5, 'y': 2, 'z': 3}
# Execute function but ignore output.
step = CodeStep(identifier='test', func=my_add)
step.exec(context=args)
assert args == {'x': 5, 'y': 2, 'z': 3}