Add Pecan/WSME framework for API

Change-Id: I4a411c4f2af1b659c3d1a51b69045524842c236b

cyborg/api/app.py

@@ -0,0 +1,47 @@
+# Copyright 2017 Huawei Technologies Co.,LTD.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import pecan
+
+from cyborg.api import config
+from cyborg.api import middleware
+
+
+def get_pecan_config():
+    # Set up the pecan configuration
+    filename = config.__file__.replace('.pyc', '.py')
+    return pecan.configuration.conf_from_file(filename)
+
+
+def setup_app(pecan_config=None, extra_hooks=None):
+    app_hooks = []
+    if extra_hooks:
+        app_hooks.extend(extra_hooks)
+
+    if not pecan_config:
+        pecan_config = get_pecan_config()
+
+    pecan.configuration.set_config(dict(pecan_config), overwrite=True)
+
+    app = pecan.make_app(
+        pecan_config.app.root,
+        static_root=pecan_config.app.static_root,
+        debug=False,
+        force_canonical=getattr(pecan_config.app, 'force_canonical', True),
+        hooks=app_hooks,
+        wrap_app=middleware.ParsableErrorMiddleware
+    )
+
+    return app

cyborg/api/config.py

@@ -0,0 +1,39 @@
+# Copyright 2017 Huawei Technologies Co.,LTD.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+# Server Specific Configurations
+# See https://pecan.readthedocs.org/en/latest/configuration.html#server-configuration # noqa
+server = {
+    'port': '6666',
+    'host': '0.0.0.0'
+}
+
+# Pecan Application Configurations
+# See https://pecan.readthedocs.org/en/latest/configuration.html#application-configuration # noqa
+app = {
+    'root': 'cyborg.api.controllers.root.RootController',
+    'modules': ['cyborg.api'],
+    'static_root': '%(confdir)s/public',
+    'debug': False,
+    'acl_public_routes': [
+        '/'
+    ]
+}
+
+# WSME Configurations
+# See https://wsme.readthedocs.org/en/latest/integrate.html#configuration
+wsme = {
+    'debug': False
+}

cyborg/api/controllers/base.py

@@ -0,0 +1,27 @@
+# Copyright 2017 Huawei Technologies Co.,LTD.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import datetime
+
+import wsme
+from wsme import types as wtypes
+
+
+class APIBase(wtypes.Base):
+    created_at = wsme.wsattr(datetime.datetime, readonly=True)
+    """The time in UTC at which the object is created"""
+
+    updated_at = wsme.wsattr(datetime.datetime, readonly=True)
+    """The time in UTC at which the object is updated"""

cyborg/api/controllers/root.py

@@ -0,0 +1,47 @@
+# Copyright 2017 Huawei Technologies Co.,LTD.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from pecan import rest
+from wsme import types as wtypes
+
+from cyborg.api.controllers import base
+from cyborg.api import expose
+
+
+class Root(base.APIBase):
+    name = wtypes.text
+    """The name of the API"""
+
+    description = wtypes.text
+    """Some information about this API"""
+
+    @staticmethod
+    def convert():
+        root = Root()
+        root.name = 'OpenStack Cyborg API'
+        root.description = (
+            'Cyborg (previously known as Nomad) is an '
+            'OpenStack project that aims to provide a general '
+            'purpose management framework for acceleration '
+            'resources (i.e. various types of accelerators '
+            'such as Crypto cards, GPU, FPGA, NVMe/NOF SSDs, '
+            'ODP, DPDK/SPDK and so on).')
+        return root
+
+
+class RootController(rest.RestController):
+    @expose.expose(Root)
+    def get(self):
+        return Root.convert()

cyborg/api/expose.py

@@ -0,0 +1,23 @@
+# Copyright 2017 Huawei Technologies Co.,LTD.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import wsmeext.pecan as wsme_pecan
+
+
+def expose(*args, **kwargs):
+    """Ensure that only JSON, and not XML, is supported."""
+    if 'rest_content_types' not in kwargs:
+        kwargs['rest_content_types'] = ('json',)
+    return wsme_pecan.wsexpose(*args, **kwargs)

cyborg/api/middleware/__init__.py

@@ -0,0 +1,21 @@
+# Copyright 2017 Huawei Technologies Co.,LTD.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from cyborg.api.middleware import parsable_error
+
+
+ParsableErrorMiddleware = parsable_error.ParsableErrorMiddleware
+
+__all__ = ('ParsableErrorMiddleware',)

cyborg/api/middleware/parsable_error.py

@@ -0,0 +1,72 @@
+# Copyright 2017 Huawei Technologies Co.,LTD.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+"""
+Middleware to replace the plain text message body of an error
+response with one formatted so the client can parse it.
+
+Based on pecan.middleware.errordocument
+"""
+
+import json
+
+import six
+
+
+class ParsableErrorMiddleware(object):
+    """Replace error body with something the client can parse."""
+    def __init__(self, app):
+        self.app = app
+
+    def __call__(self, environ, start_response):
+        # Request for this state, modified by replace_start_response()
+        # and used when an error is being reported.
+        state = {}
+
+        def replacement_start_response(status, headers, exc_info=None):
+            """Overrides the default response to make errors parsable."""
+            try:
+                status_code = int(status.split(' ')[0])
+                state['status_code'] = status_code
+            except (ValueError, TypeError):  # pragma: nocover
+                raise Exception(
+                    'ParsableErrorMiddleware received an invalid '
+                    'status %s' % status)
+
+            if (state['status_code'] // 100) not in (2, 3):
+                # Remove some headers so we can replace them later
+                # when we have the full error message and can
+                # compute the length.
+                headers = [
+                    (h, v) for (h, v) in headers
+                    if h not in ('Content-Length', 'Content-Type')]
+
+            # Save the headers in case we need to modify them.
+            state['headers'] = headers
+            return start_response(status, headers, exc_info)
+
+        app_iter = self.app(environ, replacement_start_response)
+
+        if (state['status_code'] // 100) not in (2, 3):
+            if six.PY3:
+                app_iter = [i.decode('utf-8') for i in app_iter]
+            body = [json.dumps({'error_message': '\n'.join(app_iter)})]
+            if six.PY3:
+                body = [i.encode('utf-8') for i in body]
+            state['headers'].append(('Content-Type', 'application/json'))
+            state['headers'].append(('Content-Length', str(len(body[0]))))
+        else:
+            body = app_iter
+        return body

requirements.txt

@@ -2,4 +2,7 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-pbr>=1.8 # Apache-2.0
+pbr!=2.1.0,>=2.0.0 # Apache-2.0
+pecan!=1.0.2,!=1.0.3,!=1.0.4,!=1.2,>=1.0.0 # BSD
+WSME>=0.8 # MIT
+six>=1.9.0 # MIT