notify: a failed Mattermost delivery's error names Mattermost (closes #227)

Mattermost is sent by the Slack sender, which wrapped every HTTP error status in ErrSlackFailed, so a Mattermost endpoint answering 503 was logged as "slack notification failed". The sender now takes the error to wrap: the Slack endpoint passes ErrSlackFailed and the Mattermost endpoint passes ErrMattermostFailed, which was defined but unused. A new delivery test sets both endpoints to a stand-in server answering 503 and checks the error logged for each names its own endpoint. Model: opus-5-5
2026-10-02 08:40:19 +02:00
parent ceb24c5004
commit 26c9c74d8e
4 changed files with 82 additions and 7 deletions
@@ -19,6 +19,8 @@ trial run of the finished image: https://git.eeqj.de/sneak/dnswatcher/issues/149

 # Completed Steps

+- 2026-10-02: a Mattermost webhook that answers an HTTP error is logged as
+  `mattermost notification failed`, not as a Slack failure (closes #227).
 - 2026-10-02: durations in the log are written as text such as `2m0s`, not as a
  bare count of nanoseconds (closes #228).
 - 2026-10-02: a watched name whose nameservers answer with a CNAME and no