rancher 2 webhook 格式
{
"version":"4",
"groupKey":<string>,
"status":"<resolved|firimg>",
"receiver":<string>,
"groupLabels":<object>,
"commonLabels":<object>,
"commonAnngtations":<object>,
"externalURL":<string>,
"alerts":[
{
"labels":<object>,
"annotations":<object>,
"startsAt":"<rfc3339>",
"endsAt":"<rfc3339>"
},
...
]
}