介绍：增加转换时间为持续时长用于消息模板。#312 #158
@feiyu563 @zhangsean

主要更改：

• 修改 controllers/prometheusalert.go
• 增加 controllers/prometheusalert_test.go
• 修改 controllers/public.go

Signed-off-by: jikun.zhang <jikun.zhang@megatronix.co>

配置模板
企业微信群机器人Markdown

`
{{$var:=.commonLabels}}{{ range $k,$v:=.alerts }}{{if eq $v.status "resolved"}}【恢复】{{$v.labels.alertname}}

级别：{{$v.labels.severity}}
环境：{{GetString $v.labels.env}}
持续：{{GetTimeDuration $v.startsAt}}
开始：{{GetCSTtime $v.startsAt}}
主机：{{GetString $v.labels.ip}}
{{$v.annotations.description}}{{else}}【告警】** {{$v.labels.alertname}} **
级别：{{$v.labels.severity}}
环境：{{GetString $v.labels.env}}
持续：{{GetTimeDuration $v.startsAt}}
开始：{{GetCSTtime $v.startsAt}}
主机：{{GetString $v.labels.ip}}
{{$v.annotations.description}}
{{ $urimsg:=""}}{{ range $key,$value:=$var }}{{$urimsg = print $urimsg $key "%3D%22" $value "%22%2C" }}{{end}}[☞点我屏蔽该告警☜](https://alertmanager/#/silences/new?filter=%7B{{SplitString $urimsg 0 -3}}%7D){{end}}{{end}}
`

效果演示