Mix of firing and resolved alerts is displayed incorrectly

[laurvas]

I'm migrating all alerts from Slack to Telegram right now. My testing shows wrong output from prometheus_bot.

Slack:

Telegram:

How to reproduce. The easiest way to trigger an alert is to turn off an exporter (node exporter in my case).

1. turn off some exporters.
2. wait for an alert to come.
3. turn on those exporters and turn off some other at the same time.
4. wait for a wrong alert.

Expected behavior. Firing and resolved alerts are not mixed together. I don't see the way to achieve it with custom templates.

My environment.
All running in docker:

• alertmanager:v0.16.1
• prometheus_bot:v2
• prometheus:v2.7.2

slack alerts are configured using these custom templates.

[hryamzik]

Contributions are welcomed.