Notification template reference
Grafana Cloud Enterprise Open source

Notification template reference

By default, Grafana provides predefined templates to format notification messages.

You can also customize your notifications with custom templates, which are based on the Go template language.

This documentation lists the data available for use in notification templates.

Notification Data

In notification templates, dot (.) is initialized with the following data:

NameTypeDescription
ReceiverstringThe name of the contact point sending the notification
StatusstringThe status is firing if at least one alert is firing, otherwise resolved.
Alerts[]AlertList of all firing and resolved alerts in this notification.
Alerts.Firing[]AlertList of all firing alerts in this notification.
Alerts.Resolved[]AlertList of all resolved alerts in this notification.
GroupLabelsKVThe labels that group these alerts in this notification based on the Group by option.
CommonLabelsKVThe labels common to all alerts in this notification.
CommonAnnotationsKVThe annotations common to all alerts in this notification.
ExternalURLstringA link to Grafana, or the Alertmanager that sent this notification if using an external Alertmanager.
GroupKeystringThe key used to identify this alert group.
TruncatedAlertsintegerThe number of alerts, if any, that were truncated in the notification. Supported by Webhook and OnCall.

It’s important to remember that a single notification can group multiple alerts to reduce the number of alerts you receive. Alerts is an array that includes all the alerts in the notification.

Here’s an example that prints all available notification data from dot (.):

Go
{{ define "custom_template" }}
  {{ .Receiver }}
  {{ .Status }}
  There are {{ len .Alerts }} alerts
  There are {{ len .Alerts.Firing }} firing alerts
  There are {{ len .Alerts.Resolved }} resolved alerts
  {{ .GroupLabels }}
  {{ .CommonLabels }}
  {{ .CommonAnnotations }}
  {{ .ExternalURL }}
{{ end }}

You can execute this template by passing the dot (.):

Go
{{ template "custom_template" . }}

Alert

Alert contains data for an individual alert:

NameTypeDescription
StatusstringFiring or resolved.
LabelsKVThe labels associated with this alert.
It includes all types of labels, but only query labels used in the alert condition.
AnnotationsKVThe annotations for this alert.
StartsAtTimeThe time the alert fired
EndsAtTimeOnly set if the end time of an alert is known. Otherwise set to a configurable timeout period from the time since the last alert was received.
GeneratorURLstringA link to Grafana, or the source of the alert if using an external alert generator.
FingerprintstringA unique string that identifies the alert.

Grafana-managed alerts include these additional properties:

NameTypeDescription
DashboardURLstringA link to the Grafana Dashboard if the alert has a Dashboard UID annotation.
PanelURLstringA link to the panel if the alert has a Panel ID annotation.
SilenceURLstringA link to silence the alert.
ValuesKVThe values of expressions used to evaluate the alert condition. Only relevant values are included.
ValueStringstringA string that contains the labels and value of each reduced expression in the alert.
OrgIDintegerThe ID of the organization that owns the alert.

This example iterates over the list of firing and resolved alerts (.Alerts) in the notification and prints the data for each alert:

Go
{{ define "custom_template" }}
{{ range .Alerts }}
  {{ .Status }}
  {{ .Labels }}
  {{ .Annotations }}
  {{ .StartsAt }}
  {{ .EndsAt }}
  {{ .GeneratorURL }}
  {{ .Fingerprint }}

  {{/* Only available for Grafana-managed alerts */}}
  {{ .DashboardURL }}
  {{ .PanelURL }}
  {{ .SilenceURL }}
  {{ .Values }}
  {{ .ValueString }}
{{ end }}
{{ end }}

You can run this template by passing the dot (.):

Go
{{ template "custom_template" . }}

KV

KV is a set of key value pairs, where each key and value is a string.

Similarly to accessing variable properties, you can use . to retrieve the value of a value. For example:

Go
{{ define "custom_template" }}
  {{ .CommonLabels.grafana_folder }}
{{ end }}

If a KV happens to contain numbers or bools then these are string representations of the numeric or boolean value.

Additionally, KV provides methods to sort the pairs, remove keys, and iterate over just the keys or values:

Method nameDescriptionArgumentsReturns
SortedPairsReturns a sorted list of key/value pairs.Pairs
RemoveReturns a copy of the KV with the keys removed[]stringKV
NamesReturn the names of the label names[]string
ValuesReturn a list of the values[]string

Here’s an example of using these methods:

Go
{{ define "custom_template" }}
  {{ .CommonLabels.SortedPairs }}
  {{ .CommonLabels.Names }}
  {{ .CommonLabels.Values }}
  {{ .CommonLabels.Remove (stringSlice "grafana_folder") }}
{{ end }}

Time

Some template functions and properties return a Time object, which refers to the type Time in Go’s time package.

When accessing a Time object, you can use various Time functions in your templates as follows.

Go
{{ define "custom_template" }}
  {{ range .Alerts }}
    {{ .StartsAt  }}
    {{ .StartsAt.Add 6000000000000  }}
    {{ .StartsAt.Add -6000000000000  }}
    {{ .StartsAt.AddDate 1 0 0  }}
    {{ .StartsAt.Year   }}/{{ .StartsAt.Month   }}/{{ .StartsAt.Day   }}
    {{ .StartsAt.Hour   }}:{{ .StartsAt.Minute   }}:{{ .StartsAt.Second   }}
    {{ .StartsAt.YearDay   }}-{{ .StartsAt.Weekday   }}
    {{ .StartsAt.Unix }} {{ .StartsAt.UnixMilli }}
  {{ end}}
{{ end }}

Functions

Functions can perform actions in templates such as transforming or formatting data.

Note that the functions provided by Go’s template language, such as index, and, printf, and len, are available, along with many others.

In addition, the following functions are also available for templating notifications:

NameArgumentsReturnsDescription
titlestringstringCapitalizes the first character of each word.
toUpperstringstringReturns all text in uppercase.
toLowerstringstringReturns all text in lowercase.
trimSpacestringstringRemoves leading and trailing white spaces.
matchpattern, textbooleanMatches the text against a regular expression pattern.
reReplaceAllpattern, replacement, textstringReplaces text matching the regular expression.
joinsep string, s []stringstringConcatenates the elements of s to create a single string. The separator string sep is placed between elements in the resulting string.
safeHtmlstringstringMarks string as HTML not requiring auto-escaping.
stringSlice…stringstringReturns the passed strings as a slice of strings. auto-escaping.
datestring, TimestringFormat a time in the specified format. For format options, refer to Go’s time format documentation.
tzstring, TimeTimeReturns the time in the specified timezone, such as Europe/Paris. For available timezone options, refer to the list of tz database time zones.

Here’s an example using some functions to format text:

Go
{{ define "custom_template" }}
  {{ title "hello, world!" }}
  {{ toUpper "Hello, world!" }}
  {{ toLower "Hello, world!" }}
  {{ trimSpace "Hello, world!" }}
  {{ match "a.*" "abc" }}
  {{ reReplaceAll "localhost:(.*)" "example.com:$1" "localhost:8080" }}
  {{ join "-" (stringSlice "a" "b" "c") }}
  {{ safeHtml "<b>Text</b>"}}
  {{ stringSlice "a" "b" "c" }}
{{ end }}

date and tz can format times. For example, to print the time an alert fired in the format 15:04:05 MST:

Go
{{ define "custom_template" }}
  {{ range .Alerts }}
    {{ .StartsAt | date "15:04:05 MST" }}
  {{ end}}
{{ end }}

You can then use tz to change the timezone from UTC to local time, such as Europe/Paris.

Go
{{ define "custom_template" }}
  {{ range .Alerts }}
    {{ .StartsAt | tz "Europe/Paris" }}
    {{ .StartsAt | tz "Europe/Paris" | date "15:04:05 MST" }}
  {{ end}}
{{ end }}
template-output
2024-10-30 21:01:45.227 +0100 CET
21:01:45 CET

Namespaced Functions

In addition to the top-level functions, the following namespaced functions are also available:

Collection Functions

NameArgumentsReturnsDescription
coll.Dictkey string, value any, …mapCreates a map with string keys from key/value pairs. All keys are converted to strings. If an odd number of arguments is provided, the last key will have an empty string value.
coll.Slice…any[]anyCreates a slice (array/list) from the provided arguments. Useful for creating lists that can be iterated over with range.
coll.Appendvalue any, list []any[]anyCreates a new list by appending a value to the end of an existing list. Does not modify the original list.

Example using collection functions:

Go
{{ define "collection.example" }}
{{- /* Create a dictionary of alert metadata */ -}}
{{- $metadata := coll.Dict
    "severity" "critical"
    "team" "infrastructure"
    "environment" "production"
-}}

{{- /* Create a slice of affected services */ -}}
{{- $services := coll.Slice "database" "cache" "api" -}}

{{- /* Append a new service to the list */ -}}
{{- $services = coll.Append "web" $services -}}

{{- /* Use the collections in a template */ -}}
Affected Services: {{ range $services }}{{ . }},{{ end }}

Alert Metadata:
{{- range $k, $v := $metadata }}
  {{ $k }}: {{ $v }}
{{- end }}
{{ end }}

Output:

Affected Services: database,cache,api,web,

Alert Metadata:
  environment: production
  severity: critical
  team: infrastructure

Data Functions

NameArgumentsReturnsDescription
data.JSONjsonString stringanyParses a JSON string into an object that can be manipulated in the template. Works with both JSON objects and arrays.
data.ToJSONobj anystringSerializes any object (maps, arrays, etc.) into a JSON string. Useful for creating webhook payloads.
data.ToJSONPrettyindent string, obj anystringCreates an indented JSON string representation of an object. The first argument specifies the indentation string (e.g., spaces).

Example using data functions:

Go
{{ define "data.example" }}
{{- /* First, let's create some alert data as a JSON string */ -}}
{{ $jsonString := `{
  "service": {
    "name": "payment-api",
    "environment": "production",
    "thresholds": {
      "error_rate": 5,
      "latency_ms": 100
    }
  }
}` }}

{{- /* Parse the JSON string into an object we can work with */ -}}
{{ $config := $jsonString | data.JSON }}

{{- /* Create a new alert payload */ -}}
{{ $payload := coll.Dict
    "service" $config.service.name
    "environment" $config.service.environment
    "status" .Status
    "errorThreshold" $config.service.thresholds.error_rate
}}

{{- /* Output the payload in different JSON formats */ -}}
Compact JSON: {{ $payload | data.ToJSON }}

Pretty JSON with 2-space indent:
{{ $payload | data.ToJSONPretty "  " }}
{{ end }}

Output:

Compact JSON: {"environment":"production","errorThreshold":5,"service":"payment-api","status":"resolved"}

Pretty JSON with 2-space indent:
{
  "environment": "production",
  "errorThreshold": 5,
  "service": "payment-api",
  "status": "resolved"
}

Template Functions

NameArgumentsReturnsDescription
tmpl.Execname string, [context any]stringExecutes a named template and returns the result as a string. Similar to the template action but allows for post-processing of the result.
tmpl.Inlinetemplate string, context anystringRenders a string as a template.
Go
{{ define "template.example" -}}
{{ coll.Dict
    "info" (tmpl.Exec `info` . | data.JSON)
    "severity" (tmpl.Inline `{{ print "critical" | toUpper }}` . )
    | data.ToJSONPretty " "}}
{{- end }}

{{- /* Define a sub-template */ -}}
{{ define "info" -}}
{{coll.Dict
    "team" "infrastructure"
    "environment" "production" | data.ToJSON }}
{{- end }}

Output:

json
{
  "info": {
    "environment": "production",
    "team": "infrastructure"
  },
  "severity": "CRITICAL"
}

Time Functions

NameArgumentsReturnsDescription
time.NowTimeReturns the current local time as a time.Time object. Can be formatted using Go’s time formatting functions.

Example using time functions:

Go
{{ define "time.example" }}
{{- /* Get current time in different formats */ -}}
Current Time (UTC): {{ (time.Now).UTC.Format "2006-01-02 15:04:05 MST" }}
Current Time (Local): {{ (time.Now).Format "Monday, January 2, 2006 at 15:04:05" }}

{{- /* Compare alert time with current time */ -}}
{{ $timeAgo := (time.Now).Sub .StartsAt }}
Alert fired: {{ $timeAgo }} ago
{{ end }}

Output:

Current Time (UTC): 2025-03-08 18:14:27 UTC
Current Time (Local): Saturday, March 8, 2025 at 14:14:27
Alert fired: 25h49m32.78574723s ago

Differences with annotation and label templates

In the alert rule, you can also template annotations and labels to include additional information. For example, you might add a summary annotation that displays the query value triggering the alert.

Annotation and label templates add relevant information to individual alert instances, while notification templates inform about a group of alert instances.

Since both types of templates operate in distinct contexts, the functions and variables available in annotation and label templates differ from those used in notification templates.