Telegraf: Dynamic Tags (global tags)
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Version vom 6. Mai 2020, 11:06 Uhr von Admin (Diskussion | Beiträge)
Global tags can be specified in the [global_tags] table in key="value" format. All metrics that are gathered will be tagged with the tags specified.
With dynamic tags we want the use global_tags in a more flexible way. In short: The tags should be updated dynamically.
Explanation about the workflow
We want to add the ClusterName (Hyper-V Cluster) as a global tag, because we want to filter/group by the ClusterName.
So we have three important files:
- tags.global.conf: all global tags are defined in this Telegraf configuration file.
- inputs.exec.set-globaltags.conf: this runs only the PowerShell script without any output.
- tag.set-globaltags.ps1: PowerShell script that gets information about the ClusterName and put it into a RegKey as environment variables for the service "Telegraf".
- The Telegraf Agent runs the PowerShell script tag.set-globaltags.ps1 every 4h (because of the defined "intervall" in inputs.exec.set-globaltags.conf).
- The PowerShell script tag.set-globaltags.ps1 runs a command to get the ClusterName, create/update the RegKey Environment with the ClusterName and restart the service "Telegraf".
- Because of the restart of the Telegraf service, Telegraf reads the global_tags defined in the file tags.global.conf.
- In the tags.global.conf are a tag named "Cluster" defined. This tag as the value "$ClusterName", this is an environment variable.
- Telegraf searches the environment variable "ClusterName" in the environment variable of the service (this was created/updated by the PowerShell script before).
- Telegraf find the the environment variable "ClusterName" and add a tag named Cluster with the ClusterNames as value to all metrics.
tags.global.conf
# Global tags can be specified here in key="value" format. [global_tags] # dc = "us-east-1" # will tag all metrics with dc=us-east-1 # rack = "1a" ## Environment variables can be used as tags, and throughout the config file # user = "$USER" Cluster = "$ClusterName"
inputs.exec.set-globaltags.conf
[[inputs.exec]] commands = ['powershell -NoProfile -File "C:\Program Files\Telegraf\scripts\tag.set-globaltags.ps1"'] interval = "30m" timeout = "1m"
tag.set-globaltags.ps1
### region Variables #Variable: ClusteName $ClusterName = (Get-Cluster -ErrorAction SilentlyContinue).Name ### endregion Variables # Generate an array of the variables for the RegKey $RegKeyValue =@( "ClusterName=$ClusterName", ) # Create or update the RegKey "Environment" with the Variables New-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Services\telegraf" -Name "Environment" -Value $RegKeyValue -PropertyType "MultiString" -Force | Out-Null # Restart the Telegrafg agent to apply the configuration changes Restart-Service -Name Telegraf