HTTP 307 from alertmanager is not respected

[lae]

This occurs with alertmanager 1.0.0.beta1 and 2, and with alertmanager.url set to a url with a trailing slash (e.g. /usr/bin/prometheus -alertmanager.url=http://localhost:9093/) in Prometheus:

T 127.0.0.1:34951 -> 127.0.1.1:9093 [AP]
POST //api/v1/alerts HTTP/1.1.
Host: <host>:9093.
.
<payload>

T 127.0.1.1:9093 -> 127.0.0.1:34951 [AP]
HTTP/1.1 307 Temporary Redirect.
Location: /api/v1/alerts.
Date: Thu, 04 Feb 2016 01:03:39 GMT.

Prometheus doesn't attempt to POST the data again, so Alertmanager never sees the alerts. Prometheus should respect that response code and POST the data again (for this particular problem stripping out trailing slashes from alertmanager.url would be fine, but that's ugly).

[brian-brazil]

Dupe of #668

[fabxc]

That said, this particular case can be fixed by sanitizing the appending of the API endpoint #1370.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.