add step 7

dash-apm-python/step_7.md

@@ -0,0 +1,46 @@
+We have found the function which is raising the exception
+and have determined it doesn't need to cause our application
+to fail. Let us update the code to reflect our desired changes.
+
+Open `frontend/frontend/utils.py`.
+
+Add `@tracer.wrap()` decorator to the `def get_customer_data()` function.
+
+We should have:
+
+```python
+@tracer.wrap()
+def get_customer_data():
+    current_app.logger.info('Fetching customer data')
+```
+
+This will add a span for this function so we can track when it fails.
+
+Next, open `frontend/frontend/sensors.py`.
+
+Edit `def get_sensor_data` and remove the `raise` call from the `try/except` block.
+
+As well, we can change the log line to be `current_app.logger.warn` instead of `exception`.
+
+We should end up with:
+
+```python
+
+def get_sensor_data():
+    try:
+        get_customer_data()
+    except Exception:
+        current_app.logger.warn('Failed to fetch customer data')
+
+    current_app.logger.info('Simulating refresh of sensor data')
+    resp = requests.get('http://sensors:5002/refresh_sensors', headers=get_request_headers())
+    resp.raise_for_status()
+    return resp.json()
+```
+
+
+`restart-services`{{execute interrupt}} to continue.
+
+Open the `frontend` service page to continue.
+
+https://app.datadoghq.com/apm/service/frontend