Displaying the metric value in the slack alert

Question

I have an issue with displaying the metric value in my Slack template, no matter which convention I have tried to use it did not work, it is only working if I set it in the Annotations.Description, for instance:

{{ humanize $values.B.Value }}% But when I’m trying to make it more dynamic so I can use it in all of my alerts instead of configuring each alert individually, it is not working, I’m trying to create a new value of “Current Value” which will display the metric value of the alerted instance, but for some reason, it is unable to extract the value of the metric, I have tried to declare it in many ways but nothing seems to work.

Here is the payload data of one alert that I have tried to configure for it a custom Annotation of the “Current Value” of the metric:

[
  {
    "annotations": {
      "summary": "Instance instance1 has been down for more than 5 minutes"
    },
    "labels": {
      "instance": "instance1"
    },
    "startsAt": "2024-03-13T06:41:09.128Z"
  },
  {
    "annotations": {
      "__alertId__": "50",
      "__dashboardUid__": "ebRhY1b4z",
      "__orgId__": "1",
      "__panelId__": "2",
      "__value_string__": "[ var='B' labels={DBInstanceIdentifier=node-0} value=25.516241395976735 ], [ var='C' labels={DBInstanceIdentifier=node-0} value=1 ]",
      "__values__": "{\"B\":25.516241395976735,\"C\":1}",
      "currentValue": "25.52%",
      "description": "CPU Utilization is outside normal level"
    },
    "labels": {
      "DBInstanceIdentifier": "node-0",
      "__alert_rule_uid__": "ef630ac4-0b53-4f21-aa51-3bfcf11e9e60",
      "__legacy_c_noc_test_alerts-slack__": "true",
      "__legacy_use_channels__": "true",
      "alertname": "AWS-DB (MySQL): CPU utilization alert",
      "env": "dev",
      "grafana_folder": "dev",
      "rule_uid": "ef630ac4-0b53-4f21-aa51-3bfcf11e9e60"
    },
    "startsAt": "2024-03-14T09:26:00.000Z",
    "endsAt": "2024-03-14T09:40:00.000Z"
  }
]

One example of my template that I have tried to use:

{{ define "alert_severity_prefix_emoji" }}
  {{- if ne .Status "firing" -}}:white_check_mark:
  {{- else if eq .CommonLabels.severity "critical" -}}:red_circle:
  {{- else if eq .CommonLabels.severity "warning" -}}:warning:
  {{- end }}
{{- end }}
{{ define "slack.title" }}
  {{- template "alert_severity_prefix_emoji" . }}[{{ .Status | toUpper }}{{ if eq .Status "firing" }} x {{ .Alerts.Firing | len }}{{ end }} [{{ .CommonLabels.env | toUpper }}] || {{ .CommonLabels.alertname -}}
{{- end }}
{{ define "slack.text" }}
{{ range .Alerts }}
{{ if .Annotations.summary }}*Summary:* {{ .Annotations.summary }}{{ end }}
{{ if .Annotations.description }}*Description:* {{ .Annotations.description }}{{ end }}
{{ if .Annotations.currentValue }}*Current Value:* `{{ .Annotations.currentValue }}`{{ end }}
*Labels:*
{{- range $key, $value := .Labels }}
  • {{ $key }}: `{{ $value }}`
{{- end }}
{{ end }}
{{ end }}

I’m using Grafana v10.3.1

Thank you in advance!