Implement Heartbeat Events viewing

[dannycohen]

As Opie, when the heartbeat indicator is red, I want to see the event details so I can take corrective actions, and acknowledge the events after I took corrective actions.

Visualization:

1. When clicking on the endpoint heartbeat indicator (#41) the list of active heartbeat events associated with that endpoint is displayed
2. For each event , display:
   • Event type ("Heartbeat")
   • Creation timestamp
   • Endpoint instance id
   • Time since last heartbeat message was received
3. A single heartbeat event is active per heartbeat outage
   • (i.e. assuming a heartbeat is expected every 30 seconds and its arrival is checked every 1 minute: if no heartbeat was received for 10 minutes. there will still be only 1 heartbeat event for that endpoint, and not 10 or 20 event for that specific endpoint)

Notes:

• This is a follow-up to #40 and #41, focusing on the interaction of events and acknowledging events with the indications provided by the indicators.
• An event can be set to be "active" or "cleared" (similar to email item that can be "read" or "unread"
• Events list displays only events whose status is "active"

Demo / Acceptance tests:

Case 1:

1. Deploy the heartbeat plugin in 3 of the 5 Video Store sample endpoints (in all except the ContentManagement and Operations endpoints)
2. Run the Video Store sample
3. Kill the "Sales" endpoint
4. Indicator should turn red within 1 minute
5. Number below Heartbeat Indicator should be 2 in green and 1 in red
6. Click on heartbeat indicator
7. The events list is displayed with 1 event added fro the missing "sales" heartbeat

Case 2:

1. Deploy the heartbeat plugin in 3 of the 5 Video Store sample endpoints (in all except the ContentManagement and Operations endpoints)
2. Run the Video Store sample
3. Kill the "Sales" endpoint
4. Indicator should turn red within 1 minute
5. Number below Heartbeat Indicator should be 2 in green and 1 in red
6. Click on heartbeat indicator
7. The events list is displayed with 1 even added fro the missing "sales" heartbeat
8. Create a new instance of the "Sales" endpoint
9. In the dashboard, "Sales" endpoint Indicator should turn green within 1 minute (since it starts receiving heartbeat messages from the endpoint)
10. Click on heartbeat indicator
11. The events list is displayed with 1 even added informing that the "sales" endpoint resumed sending heartbeat messages
12. In the dashboard, next to the "Sales" endpoint indicator (which is now green) there is a small icon (e.g. exclamation mark) indicating there are historical active events (i.e. "unacknowledged events")

[dannycohen]

Notes:

• Moved from https://github.com/Particular/ServiceControl/issues/42
• Replaced the term "Alerts" with "Events"

[dannycohen]

Wireframes (illustrating failed messages, but apply the same logic to heartbeats)

1. https://particular.mybalsamiq.com/projects/operations/20.%20Dashboard%20-%20Main%20View
2. https://particular.mybalsamiq.com/projects/operations/22.%20Dashboard%20-%20Endpoint%20Indicator
3. https://particular.mybalsamiq.com/projects/operations/24.%20Dashboard%20-%20Alert%20details

[indualagarsamy]

@dannycohen - Can you please update this? I am assuming that this is tied to the user story that talks about what happens when you click the heartbeat indicator?

[dannycohen]

@indualagarsamy - Updated. please review and comment.

[dannycohen]

Should include this: https://github.com/Particular/ServicePulse/issues/13