add lib for Dmaap

[modeling/etsicatalog.git] / catalog / pub / Dmaap-lib / dmaap / consumer.py

diff --git a/catalog/pub/Dmaap-lib/dmaap/consumer.py b/catalog/pub/Dmaap-lib/dmaap/consumer.py
new file mode 100644 (file)
index 0000000..054791c
--- /dev/null
+++ b/catalog/pub/Dmaap-lib/dmaap/consumer.py
@@ -0,0 +1,91 @@
+# Copyright (c) 2019, CMCC Technologies Co., Ltd.
+# 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 base64
+import hmac
+import json
+import logging
+import datetime
+import requests
+from hashlib import sha1
+
+from ..pub.exceptions import DmaapClientException
+
+logger = logging.getLogger(__name__)
+
+
+class ConsumerClient:
+    def __init__(self, host, topic, consumer_group, consumer_id, timeout_ms=-1, limit=-1, filter='',
+                 api_key='', api_secret=''):
+        self.host = host
+        self.topic = topic
+        self.group = consumer_group
+        self.comsumer_id = consumer_id
+        self.timeout_ms = timeout_ms
+        self.limit = limit
+        self.filter = filter
+        self.api_key = api_key
+        self.api_secret = api_secret
+
+    def set_api_credentials(self, api_key, api_secret):
+
+        self.api_key = api_key
+        self.api_secret = api_secret
+
+    def create_url(self):
+        url = "http://%s/events/%s/%s/%s" % (self.host, self.topic, self.group, self.comsumer_id)
+        add_url = ""
+        if self.timeout_ms > -1:
+            add_url += "timeout=%s" % self.timeout_ms
+        if self.limit > -1:
+            if add_url:
+                add_url += "&"
+            add_url += "limit=%s" % self.limit
+        if self.filter:
+            if add_url:
+                add_url += "&"
+            add_url += "filter=%s" % self.filter.encode("utf-8")
+        if add_url:
+            url = url + "?" + add_url
+
+        return url
+
+    def create_headers(self):
+        data = datetime.datetime.now().strftime('%Y-%m-%dT%H:%M:%S') + '-04:00'
+        hmac_code = hmac.new(self.api_secret.encode(), data.encode(), sha1).digest()
+        signature = base64.b64encode(hmac_code).decode()
+        auth = self.api_key + ':' + signature
+        headers = {
+            'X-CambriaDate': data,
+            'X-CambriaAuth': auth
+        }
+        return headers
+
+    def fetch(self):
+        try:
+            msgs = []
+            url = self.create_url()
+            if self.api_key:
+                headers = self.create_headers()
+                ret = requests.get(url=url, headers=headers)
+            else:
+                ret = requests.get(url)
+            logger.info("Status code is %s, detail is %s.", ret.status_code, ret.json())
+            if ret.status_code != 200:
+                raise DmaapClientException('Call dmaap failed. Status code is %s, detail is %s.' % (ret.status_code, ret.json()))
+            data = ret.json()
+            for msg in data:
+                msg = json.loads(msg)
+                msgs.append(msg)
+            return msgs
+        except Exception as e:
+            raise DmaapClientException(e.message)