AlertManager donot send alert to webhook

[luca-amato]

I try to use webhook in my env.
I install webhook in a pod and I run it using
webhook -hooks hooks.json -verbose

I show some messages at runtime and at the end it shows the following message
[webhook] 2024/10/03 15:48:45 os signal watcher ready

So I test the network connection using curl using
curl http://ubuntu.mon.svc.cluster.local:9000/hooks/redeploy-webhook

in webhook I see the answer
[webhook] 2024/10/03 16:21:08 [7d2780] incoming HTTP GET request from 10.128.8.1:15211
[webhook] 2024/10/03 16:21:08 [7d2780] redeploy-webhook got matched
[webhook] 2024/10/03 16:21:08 [7d2780] error parsing body payload due to unsupported content type header:
[webhook] 2024/10/03 16:21:08 [7d2780] redeploy-webhook hook triggered successfully
[webhook] 2024/10/03 16:21:08 [7d2780] 200 | 0 B | 61.612µs | ubuntu.mon.svc.cluster.local:9000 | GET /hooks/redeploy-webhook
[webhook] 2024/10/03 16:21:08 [7d2780] executing /backup/myhook.sh (/backup/myhook.sh) with arguments ["/backup/myhook.sh"] and environment [] using /backup as cwd
[webhook] 2024/10/03 16:21:08 [7d2780] command output:
[webhook] 2024/10/03 16:21:08 [7d2780] finished handling redeploy-webhook

So I configure alertManager and this is my alertmanager status:
....

• receiver: webhook
  match_re:
  severity: critical|warning
  continue: true
  group_wait: 15m
  group_wait: 15m
  group_interval: 15m
  ...
• name: webhook
  webhook_configs:
  • send_resolved: true
    http_config:
    follow_redirects: true
    enable_http2: true
    url: http://ubuntu.mon.svc.cluster.local:9000/hooks/redeploy-webhook
    max_alerts: 0

Now I fired an alert and I find it inside alertManager log
ts=2024-10-03T16:16:14.008Z caller=dispatch.go:515 level=debug component=dispatcher aggrGroup="{}:{alertname="myalert"}" msg=flushing alerts=[myalert[c4b74c5][resolved]]
ts=2024-10-03T16:25:07.739Z caller=dispatch.go:163 level=debug component=dispatcher msg="Received alert" alert=myalert[c4b74c5][active]

but in webhook I do not receive anything

can someone help me to understand why it does not work?

Many thanks in advence for any suggestion

Luca

[luca-amato]

I found the problem.
When there are more webhook in the alertmanager routes you mast to use match-_re option in this way:

• match_re:
  alertname: ".*"
  receiver: 'webhook'
  continue: true

one for each webhook destination that you need to manage

I suggest to insert some alertmanager.yml example in the github in order to solve some alertmanager configuration misleading

here is my correct yml

lobal:
smtp_require_tls: true
route:
receiver: 'webhook'
group_by: ['alertname']
group_wait: 30s
group_interval: 1m
repeat_interval: 1m
routes:

• match_re:
  alertname: ".*"
  receiver: 'srv_notifier'
  continue: true
• match_re:
  alertname: ".*"
  receiver: 'webhook'
  continue: true
  receivers:
• name: webhook
  webhook_configs:
  • send_resolved: true
    http_config:
    follow_redirects: true
    enable_http2: true
    url: http://server01:9000/hooks/redeploy-webhook
    max_alerts: 0
• name: srv_notifier
  webhook_configs:
  • send_resolved: true
    http_config:
    follow_redirects: true
    enable_http2: true
    url: http://server02:9000/alerts
    max_alerts: 0

Bye