slack receiver should use webhook instead of token

[aavileli]

slack is depreciating slack tokens

[mustafaakin]

Then it's a very good first issue to contribute.

[wcarlsen]

I think the webhook sink is covering this use case, considering incoming webhooks in Slack (https://api.slack.com/messaging/webhooks). I tested it and it works flawless. Of course you need to play with the layout, but I think one can live with this.
Maybe consider deprecating the Slack sink and recommend the webhook sink instead, since Slack recommends not using legacy tokens?

[minac]

Hey @wcarlsen! I could use a hand, how did you configure the Slack webhook?

receivers:
      - name: "slack"
        webhook:
          endpoint: "https://hooks.slack.com/services/bla/bla/bla"
          headers:
            User-Agent: kube-event-exporter 1.0

Did you use any API Token? When setting up Incoming Webhooks in Slack there are no tokens now, right?

Thanks!

[wcarlsen]

@minac if I recall it right, I was just adding an incoming webhook like you probably already did. My config.yaml was probably very similar to this:

logLevel: debug
route:
  # Main route
  routes:
    # This route allows dumping all events because it has no fields to match and no drop rules.
    - match:
        - receiver: "alert"
receivers:
  - name: "alert"
    webhook:
      endpoint: "https://hooks.slack.com/services/bla/bla/bla"
      layout:
        text: "{{.Message}}"

Hope it helped. You have to play around with the layout a bit to make it nice. But styling is probably a personal thing. Good luck!

[minac]

I was missing that last bit of the layout. Thank you!

[mrsiejas]

Thanks @wcarlsen, this should be added to the docs. Also wasted few hours to realise I missed the layout section.