Source code for openquake.server.views

# -*- coding: utf-8 -*-
# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright (C) 2015-2022 GEM Foundation
# OpenQuake is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# OpenQuake is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# GNU Affero General Public License for more details.
# You should have received a copy of the GNU Affero General Public License
# along with OpenQuake. If not, see <>.

import shutil
import json
import string
import pickle
import logging
import os
import tempfile
import subprocess
import multiprocessing
import traceback
import signal
import zlib
import urllib.parse as urlparse
import re
import psutil
from datetime import datetime
from urllib.parse import unquote_plus
from xml.parsers.expat import ExpatError
from django.http import (
    HttpResponse, HttpResponseNotFound, HttpResponseBadRequest,
from django.views.decorators.csrf import csrf_exempt
from django.views.decorators.http import require_http_methods
from django.shortcuts import render

from openquake.baselib import hdf5, config
from openquake.baselib.general import groupby, gettemp, zipfiles
from openquake.hazardlib import nrml, gsim, valid
from openquake.commonlib import readinput, oqvalidation, logs, datastore
from openquake.calculators import base
from openquake.calculators.getters import NotFound
from openquake.calculators.export import export
from openquake.calculators.extract import extract as _extract
from openquake.engine import __version__ as oqversion
from openquake.engine.export import core
from openquake.engine import engine
from openquake.engine.export.core import DataStoreExportError
from openquake.server import utils, dbapi

from django.conf import settings
from django.http import FileResponse
from wsgiref.util import FileWrapper

if settings.LOCKDOWN:
    from django.contrib.auth import authenticate, login, logout

Process = multiprocessing.get_context('spawn').Process

CWD = os.path.dirname(__file__)

XML = 'application/xml'
JSON = 'application/json'
HDF5 = 'application/x-hdf'

#: For exporting calculation outputs, the client can request a specific format
#: (xml, geojson, csv, etc.). If the client does not specify give them (NRML)
#: XML by default.


LOGGER = logging.getLogger('openquake.server')

ACCESS_HEADERS = {'Access-Control-Allow-Origin': '*',
                  'Access-Control-Allow-Methods': 'GET, POST, OPTIONS',
                  'Access-Control-Max-Age': 1000,
                  'Access-Control-Allow-Headers': '*'}

KUBECTL = "kubectl apply -f -".split()
ENGINE = "python -m openquake.engine.engine".split()

# disable check on the export_dir, since the WebUI exports in a tmpdir
oqvalidation.OqParam.is_valid_export_dir = lambda self: True

# Credit for this decorator to
[docs]def cross_domain_ajax(func): def wrap(request, *args, **kwargs): # Firefox sends 'OPTIONS' request for cross-domain javascript call. if not request.method == "OPTIONS": response = func(request, *args, **kwargs) else: response = HttpResponse() for k, v in list(ACCESS_HEADERS.items()): response[k] = v return response return wrap
def _get_base_url(request): """ Construct a base URL, given a request object. This comprises the protocol prefix (http:// or https://) and the host, which can include the port number. For example: or """ if request.is_secure(): base_url = 'https://%s' else: base_url = 'http://%s' base_url %= request.META['HTTP_HOST'] return base_url
[docs]def store(request_files, ini, calc_id): """ Store the uploaded files in calc_dir and select the job file by looking at the .ini extension. :returns: full path of the ini file """ tmp = or tempfile.mkdtemp() calc_dir = os.path.join(tmp, 'calc_%d' % calc_id) os.mkdir(calc_dir) arch = request_files.get('archive') if arch is None: # move each file to calc_dir using the upload file names inifiles = [] for each_file in sorted(request_files.values()): new_path = os.path.join(calc_dir, shutil.move(each_file.temporary_file_path(), new_path) if inifiles.append(new_path) else: # extract the files from the archive into calc_dir inifiles = readinput.extract_from_zip(arch, ini, calc_dir) if not inifiles: raise NotFound('There are no %s files in the archive' % ini) return inifiles[0]
[docs]@csrf_exempt @cross_domain_ajax @require_http_methods(['POST']) def ajax_login(request): """ Accept a POST request to login. :param request: `django.http.HttpRequest` object, containing mandatory parameters username and password required. """ username = request.POST['username'] password = request.POST['password'] user = authenticate(username=username, password=password) if user is not None: if user.is_active: login(request, user) return HttpResponse(content='Successful login', content_type='text/plain', status=200) else: return HttpResponse(content='Disabled account', content_type='text/plain', status=403) else: return HttpResponse(content='Invalid login', content_type='text/plain', status=403)
[docs]@csrf_exempt @cross_domain_ajax @require_http_methods(['POST']) def ajax_logout(request): """ Accept a POST request to logout. """ logout(request) return HttpResponse(content='Successful logout', content_type='text/plain', status=200)
[docs]@cross_domain_ajax @require_http_methods(['GET']) def get_engine_version(request): """ Return a string with the openquake.engine version """ return HttpResponse(oqversion)
[docs]@cross_domain_ajax @require_http_methods(['GET']) def get_engine_latest_version(request): """ Return a string with if new versions have been released. Return 'None' if the version is not available """ return HttpResponse(engine.check_obsolete_version())
[docs]@cross_domain_ajax @require_http_methods(['GET']) def get_available_gsims(request): """ Return a list of strings with the available GSIMs """ gsims = list(gsim.get_available_gsims()) return HttpResponse(content=json.dumps(gsims), content_type=JSON)
[docs]@cross_domain_ajax @require_http_methods(['GET']) def get_ini_defaults(request): """ Return a list of ini attributes with a default value """ ini_defs = {} all_names = dir(oqvalidation.OqParam) + list(oqvalidation.OqParam.ALIASES) for name in all_names: if name in oqvalidation.OqParam.ALIASES: # old name newname = oqvalidation.OqParam.ALIASES[name] else: newname = name obj = getattr(oqvalidation.OqParam, newname) if (isinstance(obj, valid.Param) and obj.default is not valid.Param.NODEFAULT): ini_defs[name] = obj.default return HttpResponse(content=json.dumps(ini_defs), content_type=JSON)
def _make_response(error_msg, error_line, valid): response_data = dict(error_msg=error_msg, error_line=error_line, valid=valid) return HttpResponse( content=json.dumps(response_data), content_type=JSON)
[docs]@csrf_exempt @cross_domain_ajax @require_http_methods(['POST']) def validate_nrml(request): """ Leverage oq-risklib to check if a given XML text is a valid NRML :param request: a `django.http.HttpRequest` object containing the mandatory parameter 'xml_text': the text of the XML to be validated as NRML :returns: a JSON object, containing: * 'valid': a boolean indicating if the provided text is a valid NRML * 'error_msg': the error message, if any error was found (None otherwise) * 'error_line': line of the given XML where the error was found (None if no error was found or if it was not a validation error) """ xml_text = request.POST.get('xml_text') if not xml_text: return HttpResponseBadRequest( 'Please provide the "xml_text" parameter') xml_file = gettemp(xml_text, suffix='.xml') try: nrml.to_python(xml_file) except ExpatError as exc: return _make_response(error_msg=str(exc), error_line=exc.lineno, valid=False) except Exception as exc: # get the exception message exc_msg = exc.args[0] if isinstance(exc_msg, bytes): exc_msg = exc_msg.decode('utf-8') # make it a unicode object elif isinstance(exc_msg, str): pass else: # if it is another kind of object, it is not obvious a priori how # to extract the error line from it return _make_response( error_msg=str(exc_msg), error_line=None, valid=False) # if the line is not mentioned, the whole message is taken error_msg = exc_msg.split(', line')[0] # check if the exc_msg contains a line number indication search_match ='line \d+', exc_msg) if search_match: error_line = int([1]) else: error_line = None return _make_response( error_msg=error_msg, error_line=error_line, valid=False) else: return _make_response(error_msg=None, error_line=None, valid=True)
[docs]@csrf_exempt @cross_domain_ajax @require_http_methods(['POST']) def validate_zip(request): """ Leverage the engine libraries to check if a given zip archive is a valid calculation input :param request: a `django.http.HttpRequest` object containing a zip archive :returns: a JSON object, containing: * 'valid': a boolean indicating if the provided archive is valid * 'error_msg': the error message, if any error was found (None otherwise) """ archive = request.FILES.get('archive') if not archive: return HttpResponseBadRequest('Missing archive file') job_zip = archive.temporary_file_path() try: oq = readinput.get_oqparam(job_zip) base.calculators(oq, calc_id=None).read_inputs() except Exception as exc: return _make_response(str(exc), None, valid=False) else: return _make_response(None, None, valid=True)
[docs]@require_http_methods(['GET']) @cross_domain_ajax def hmap_png(request, calc_id, imt_id, poe_id): """ Get a PNG image with the relevant mean hazard map, if available """ job = logs.dbcmd('get_job', int(calc_id)) if job is None: return HttpResponseNotFound() if not utils.user_has_permission(request, job.user_name): return HttpResponseForbidden() try: from PIL import Image response = HttpResponse(content_type="image/png") with + '.hdf5') as ds: arr = ds['png/hmap_%s_%s' % (imt_id, poe_id)][:] Image.fromarray(arr).save(response, format='png') return response except Exception as exc: tb = ''.join(traceback.format_tb(exc.__traceback__)) return HttpResponse( content='%s: %s\n%s' % (exc.__class__.__name__, exc, tb), content_type='text/plain', status=500)
[docs]@require_http_methods(['GET']) @cross_domain_ajax def calc(request, calc_id): """ Get a JSON blob containing all of parameters for the given calculation (specified by ``calc_id``). Also includes the current job status ( executing, complete, etc.). """ try: info = logs.dbcmd('calc_info', calc_id) if not utils.user_has_permission(request, info['user_name']): return HttpResponseForbidden() except dbapi.NotFound: return HttpResponseNotFound() return HttpResponse(content=json.dumps(info), content_type=JSON)
[docs]@require_http_methods(['GET']) @cross_domain_ajax def calc_list(request, id=None): # view associated to the endpoints /v1/calc/list and /v1/calc/:id/status """ Get a list of calculations and report their id, status, calculation_mode, is_running, description, and a url where more detailed information can be accessed. This is called several times by the Javascript. Responses are in JSON. """ base_url = _get_base_url(request) # always filter calculation list unless user is a superuser calc_data = logs.dbcmd('get_calcs', request.GET, utils.get_valid_users(request), not utils.is_superuser(request), id) response_data = [] username = psutil.Process(os.getpid()).username() for (hc_id, owner, status, calculation_mode, is_running, desc, pid, parent_id, size_mb) in calc_data: url = urlparse.urljoin(base_url, 'v1/calc/%d' % hc_id) abortable = False if is_running: try: if psutil.Process(pid).username() == username: abortable = True except psutil.NoSuchProcess: pass response_data.append( dict(id=hc_id, owner=owner, calculation_mode=calculation_mode, status=status, is_running=bool(is_running), description=desc, url=url, parent_id=parent_id, abortable=abortable, size_mb=size_mb)) # if id is specified the related dictionary is returned instead the list if id is not None: if not response_data: return HttpResponseNotFound() [response_data] = response_data return HttpResponse(content=json.dumps(response_data), content_type=JSON)
[docs]@csrf_exempt @cross_domain_ajax @require_http_methods(['POST']) def calc_abort(request, calc_id): """ Abort the given calculation, it is it running """ job = logs.dbcmd('get_job', calc_id) if job is None: message = {'error': 'Unknown job %s' % calc_id} return HttpResponse(content=json.dumps(message), content_type=JSON) if job.status not in ('submitted', 'executing'): message = {'error': 'Job %s is not running' %} return HttpResponse(content=json.dumps(message), content_type=JSON) # only the owner or superusers can abort a calculation if (job.user_name not in utils.get_valid_users(request) and not utils.is_superuser(request)): message = {'error': ('User %s has no permission to abort job %s' % (request.user,} return HttpResponse(content=json.dumps(message), content_type=JSON, status=403) if # is a spawned job try: os.kill(, signal.SIGINT) except Exception as exc: logging.error(exc) else: logging.warning('Aborting job %d, pid=%d',, logs.dbcmd('set_status',, 'aborted') message = {'success': 'Killing job %d' %} return HttpResponse(content=json.dumps(message), content_type=JSON) message = {'error': 'PID for job %s not found' %} return HttpResponse(content=json.dumps(message), content_type=JSON)
[docs]@csrf_exempt @cross_domain_ajax @require_http_methods(['POST']) def calc_remove(request, calc_id): """ Remove the calculation id """ # Only the owner can remove a job user = utils.get_user(request) try: message = logs.dbcmd('del_calc', calc_id, user) except dbapi.NotFound: return HttpResponseNotFound() if 'success' in message: return HttpResponse(content=json.dumps(message), content_type=JSON, status=200) elif 'error' in message: logging.error(message['error']) return HttpResponse(content=json.dumps(message), content_type=JSON, status=403) else: # This is an untrapped server error logging.error(message) return HttpResponse(content=message, content_type='text/plain', status=500)
[docs]def log_to_json(log): """Convert a log record into a list of strings""" return [log.timestamp.isoformat()[:22], log.level, log.process, log.message]
[docs]@require_http_methods(['GET']) @cross_domain_ajax def calc_log(request, calc_id, start, stop): """ Get a slice of the calculation log as a JSON list of rows """ start = start or 0 stop = stop or 0 try: response_data = logs.dbcmd('get_log_slice', calc_id, start, stop) except dbapi.NotFound: return HttpResponseNotFound() return HttpResponse(content=json.dumps(response_data), content_type=JSON)
[docs]@require_http_methods(['GET']) @cross_domain_ajax def calc_log_size(request, calc_id): """ Get the current number of lines in the log """ try: response_data = logs.dbcmd('get_log_size', calc_id) except dbapi.NotFound: return HttpResponseNotFound() return HttpResponse(content=json.dumps(response_data), content_type=JSON)
[docs]@csrf_exempt @cross_domain_ajax @require_http_methods(['POST']) def calc_run(request): """ Run a calculation. :param request: a `django.http.HttpRequest` object. If the request has the attribute `hazard_job_id`, the results of the specified hazard calculations will be re-used as input by the risk calculation. The request also needs to contain the files needed to perform the calculation. They can be uploaded as separate files, or zipped together. """ job_ini = request.POST.get('job_ini') hazard_job_id = request.POST.get('hazard_job_id') if hazard_job_id: # "continue" button, tested in the QGIS plugin ini = job_ini if job_ini else "risk.ini" else: ini = job_ini if job_ini else ".ini" user = utils.get_user(request) try: job_id = submit_job(request.FILES, ini, user, hazard_job_id) except Exception as exc: # no job created, for instance missing .xml file # get the exception message exc_msg = traceback.format_exc() + str(exc) logging.error(exc_msg) response_data = exc_msg.splitlines() status = 500 else: response_data = dict(status='created', job_id=job_id) status = 200 return HttpResponse(content=json.dumps(response_data), content_type=JSON, status=status)
[docs]def submit_job(request_files, ini, username, hc_id): """ Create a job object from the given files and run it in a new process. :returns: a job ID """ # build a LogContext object associated to a database job [job] = engine.create_jobs( [dict(calculation_mode='preclassical', description='Calculation waiting to start')], config.distribution.log_level, None, username, hc_id) # store the request files and perform some validation try: job_ini = store(request_files, ini, job.calc_id) job.oqparam = oq = readinput.get_oqparam( job_ini, kw={'hazard_calculation_id': hc_id}) if oq.sensitivity_analysis: logs.dbcmd('set_status', job.calc_id, 'deleted') # hide it jobs = engine.create_jobs([job_ini], config.distribution.log_level, None, username, hc_id, True) else: dic = dict(calculation_mode=oq.calculation_mode, description=oq.description, hazard_calculation_id=hc_id) logs.dbcmd('update_job', job.calc_id, dic) jobs = [job] except Exception: tb = traceback.format_exc() logs.dbcmd('log', job.calc_id, datetime.utcnow(), 'CRITICAL', 'before starting', tb) logs.dbcmd('finish', job.calc_id, 'failed') raise custom_tmp = os.path.dirname(job_ini) submit_cmd = config.distribution.submit_cmd.split() big_job = oq.get_input_size() > int(config.distribution.min_input_size) if submit_cmd == ENGINE: # used for debugging for job in jobs: subprocess.Popen(submit_cmd + [save(job, custom_tmp)]) elif submit_cmd == KUBECTL and big_job: for job in jobs: with open(os.path.join(CWD, 'job.yaml')) as f: yaml = string.Template( DATABASE='%(host)s:%(port)d' % config.dbserver, CALC_PIK=save(job, custom_tmp), CALC_NAME='calc%d' % job.calc_id), input=yaml.encode('ascii')) else: Process(target=engine.run_jobs, args=(jobs,)).start() return job.calc_id
[docs]def save(job, dirname): """ Save a LogContext object in pickled format; returns the path to it """ pathpik = os.path.join(dirname, 'calc%d.pik' % job.calc_id) with open(pathpik, 'wb') as f: pickle.dump(job, f) return pathpik
[docs]@require_http_methods(['GET']) @cross_domain_ajax def calc_results(request, calc_id): """ Get a summarized list of calculation results for a given ``calc_id``. Result is a JSON array of objects containing the following attributes: * id * name * type (hazard_curve, hazard_map, etc.) * url (the exact url where the full result can be accessed) """ # If the specified calculation doesn't exist OR is not yet complete, # throw back a 404. try: info = logs.dbcmd('calc_info', calc_id) if not utils.user_has_permission(request, info['user_name']): return HttpResponseForbidden() except dbapi.NotFound: return HttpResponseNotFound() base_url = _get_base_url(request) # NB: export_output has as keys the list (output_type, extension) # so this returns an ordered map output_type -> extensions such as # {'agg_loss_curve': ['xml', 'csv'], ...} output_types = groupby(export, lambda oe: oe[0], lambda oes: [e for o, e in oes]) results = logs.dbcmd('get_outputs', calc_id) if not results: return HttpResponseNotFound() response_data = [] for result in results: try: # output from the datastore rtype = result.ds_key # Catalina asked to remove the .txt outputs (used for the GMFs) outtypes = [ot for ot in output_types[rtype] if ot != 'txt'] except KeyError: continue # non-exportable outputs should not be shown url = urlparse.urljoin(base_url, 'v1/calc/result/%d' % datum = dict(, name=result.display_name, type=rtype, outtypes=outtypes, url=url, size_mb=result.size_mb) response_data.append(datum) return HttpResponse(content=json.dumps(response_data))
[docs]@require_http_methods(['GET']) @cross_domain_ajax def calc_traceback(request, calc_id): """ Get the traceback as a list of lines for a given ``calc_id``. """ # If the specified calculation doesn't exist throw back a 404. try: response_data = logs.dbcmd('get_traceback', calc_id) except dbapi.NotFound: return HttpResponseNotFound() return HttpResponse(content=json.dumps(response_data), content_type=JSON)
[docs]@cross_domain_ajax @require_http_methods(['GET', 'HEAD']) def calc_result(request, result_id): """ Download a specific result, by ``result_id``. The common abstracted functionality for getting hazard or risk results. :param request: `django.http.HttpRequest` object. Can contain a `export_type` GET param (the default is 'xml' if no param is specified). :param result_id: The id of the requested artifact. :returns: If the requested ``result_id`` is not available in the format designated by the `export_type`. Otherwise, return a `django.http.HttpResponse` containing the content of the requested artifact. Parameters for the GET request can include an `export_type`, such as 'xml', 'geojson', 'csv', etc. """ # If the result for the requested ID doesn't exist, OR # the job which it is related too is not complete, # throw back a 404. try: job_id, job_status, job_user, datadir, ds_key = logs.dbcmd( 'get_result', result_id) if not utils.user_has_permission(request, job_user): return HttpResponseForbidden() except dbapi.NotFound: return HttpResponseNotFound() etype = request.GET.get('export_type') export_type = etype or DEFAULT_EXPORT_TYPE tmpdir = tempfile.mkdtemp() try: exported = core.export_from_db( (ds_key, export_type), job_id, datadir, tmpdir) except DataStoreExportError as exc: # TODO: there should be a better error page return HttpResponse(content='%s: %s' % (exc.__class__.__name__, exc), content_type='text/plain', status=500) if not exported: # Throw back a 404 if the exact export parameters are not supported return HttpResponseNotFound( 'Nothing to export for export_type=%s, %s' % (export_type, ds_key)) elif len(exported) > 1: # Building an archive so that there can be a single file download archname = ds_key + '-' + export_type + '.zip' zipfiles(exported, os.path.join(tmpdir, archname)) exported = os.path.join(tmpdir, archname) else: # single file exported = exported[0] content_type = EXPORT_CONTENT_TYPE_MAP.get( export_type, DEFAULT_CONTENT_TYPE) fname = 'output-%s-%s' % (result_id, os.path.basename(exported)) stream = FileWrapper(open(exported, 'rb')) # 'b' is needed on Windows stream.close = lambda: ( FileWrapper.close(stream), shutil.rmtree(tmpdir)) response = FileResponse(stream, content_type=content_type) response['Content-Disposition'] = ( 'attachment; filename=%s' % os.path.basename(fname)) response['Content-Length'] = str(os.path.getsize(exported)) return response
[docs]@cross_domain_ajax @require_http_methods(['GET', 'HEAD']) def extract(request, calc_id, what): """ Wrapper over the `oq extract` command. If `setting.LOCKDOWN` is true only calculations owned by the current user can be retrieved. """ job = logs.dbcmd('get_job', int(calc_id)) if job is None: return HttpResponseNotFound() if not utils.user_has_permission(request, job.user_name): return HttpResponseForbidden() path = request.get_full_path() n = len(request.path_info) query_string = unquote_plus(path[n:]) try: # read the data and save them on a temporary .npz file with + '.hdf5') as ds: fd, fname = tempfile.mkstemp( prefix=what.replace('/', '-'), suffix='.npz') os.close(fd) obj = _extract(ds, what + query_string) hdf5.save_npz(obj, fname) except Exception as exc: tb = ''.join(traceback.format_tb(exc.__traceback__)) return HttpResponse( content='%s: %s in %s\n%s' % (exc.__class__.__name__, exc, path, tb), content_type='text/plain', status=500) # stream the data back stream = FileWrapper(open(fname, 'rb')) stream.close = lambda: (FileWrapper.close(stream), os.remove(fname)) response = FileResponse(stream, content_type='application/octet-stream') response['Content-Disposition'] = ( 'attachment; filename=%s' % os.path.basename(fname)) response['Content-Length'] = str(os.path.getsize(fname)) return response
[docs]@cross_domain_ajax @require_http_methods(['GET']) def calc_datastore(request, job_id): """ Download a full datastore file. :param request: `django.http.HttpRequest` object. :param job_id: The id of the requested datastore :returns: A `django.http.HttpResponse` containing the content of the requested artifact, if present, else throws a 404 """ job = logs.dbcmd('get_job', int(job_id)) if job is None or not os.path.exists(job.ds_calc_dir + '.hdf5'): return HttpResponseNotFound() if not utils.user_has_permission(request, job.user_name): return HttpResponseForbidden() fname = job.ds_calc_dir + '.hdf5' response = FileResponse( FileWrapper(open(fname, 'rb')), content_type=HDF5) response['Content-Disposition'] = ( 'attachment; filename=%s' % os.path.basename(fname)) response['Content-Length'] = str(os.path.getsize(fname)) return response
[docs]def web_engine(request, **kwargs): return render(request, "engine/index.html", {})
[docs]@cross_domain_ajax @require_http_methods(['GET']) def web_engine_get_outputs(request, calc_id, **kwargs): job = logs.dbcmd('get_job', calc_id) with + '.hdf5') as ds: hmaps = 'png' in ds size_mb = '?' if job.size_mb is None else '%.2f' % job.size_mb return render(request, "engine/get_outputs.html", dict(calc_id=calc_id, size_mb=size_mb, hmaps=hmaps))
[docs]@csrf_exempt @cross_domain_ajax @require_http_methods(['POST']) def on_same_fs(request): """ Accept a POST request to check access to a FS available by a client. :param request: `django.http.HttpRequest` object, containing mandatory parameters filename and checksum. """ filename = request.POST['filename'] checksum_in = request.POST['checksum'] checksum = 0 try: data = open(filename, 'rb').read(32) checksum = zlib.adler32(data, checksum) & 0xffffffff if checksum == int(checksum_in): return HttpResponse(content=json.dumps({'success': True}), content_type=JSON, status=200) except (IOError, ValueError): pass return HttpResponse(content=json.dumps({'success': False}), content_type=JSON, status=200)
[docs]@require_http_methods(['GET']) def license(request, **kwargs): return render(request, "engine/license.html")