Webhook Receiver should support custom headers

[njohnstone2]

The webhook receiver should have the ability to add arbitrary headers to a http request.

When configuring a webhook contact point it is common that the webhook receiver requires additional arbitrary headers to process the request (e.g. "X-" headers).

This issue would also require a UI change in grafana to allow the additional headers to be defined in the UI

[armandgrillet]

The challenge is that we want to unify our receivers with the ones in the Prometheus Alertmanager repository in the long term, and this issue + PR go against that. You should propose the idea to https://github.com/prometheus/alertmanager/issues instead.

[armandgrillet]

Related PRs:

• added support for extra headers on the webhook receiver #135
• Alerting: Webhook contact point support custom headers grafana#77668

This does not change the fact that this should first be done in the Prometheus Alertmanager repository so that we do not go against upstream.

[WesselAtWork]

Turns out the intended way of dealing with arbitrary alerts in prom/alertmanager is to use a custom middleware that forwards the webhook to the upstream.

There seems to be many many feature requests the effect of "Please Add X Integration" or "Please modify webhooks so we can make arbitrary requests" or a more reasonable "Please allow us to template the body of the webhooks"

It looks like they have decided (implicitly) that the burdun of implementation is on the server side.

I doubt they will be open to adding custom headers, even if they were static.
prometheus/alertmanager#2268

See also:
prometheus/alertmanager#709 (comment)
prometheus/alertmanager#2184 (comment)
prometheus/alertmanager#1496 (comment)

---

Are there plans to add additional grafana-only receivers?
I don't think there are connector plugins available but I could be wrong.

[christianherweg0807]

That would be great, especially for routing messages, when replacing the deprecated teams Webhook with PowerAutomate Workflows for multiple Teams Channels.

We think about headers like ChannelID & TeamID to route the Alarm to the correct destination & team