Varnish Cache integration for Grafana Cloud

Before you begin

In order for the integration to properly work, you must set up the Varnish Cache exporter for Prometheus to export metrics from Varnish.

Set up Varnish Cache exporter

Install the version of the exporter that corresponds to your operating system. The latest releases and installs can be found on exporter installation. To start the exporter first unzip the file that you downloaded above and traverse to the directory where the executable is. The executable will be named similar to prometheus_varnish_exporter. An example of the exporter being run is shown below:

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sudo ./prometheus_varnish_exporter

The above will run a

bash Copy

varnishstat -j

behind the scenes and open a port 9131 that can be accessed through localhost:9131. The exported Prometheus metrics can be seen at localhost:9131/metrics.

The exporter exposes port 9131 by default but you can change this using the -web.listen-address flag when running the exporter. The use of this flag would look like this:

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sudo ./prometheus_varnish_exporter -web.listen-address localhost:9595

If you have multiple Varnish instances, you must specify which you are targeting with the exporter. This can be done by running the exporter with the flag -n and the name of your varnish instance. Example shown below:

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sudo ./prometheus_varnish_exporter -n <instance_name>

This also means you would need one exporter for each instance of Varnish Cache, each with a unique port.

For more options and help with the exporter, you can run the below command:

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sudo ./prometheus_varnish_exporter -h

Once deployed, Grafana Alloy should be able to reach the Varnish Cache exporter’s exposed endpoint in order to scrape metrics.

Set up Varnish Cache logging

This integration leverages the varnishncsa utility provided by Varnish in order to produce formatted logs. Any format of log collection with varnishncsa will be picked up by the integration.

In order to setup varnishncsa, the utility must be enabled by running:

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sudo systemctl enable varnishncsa
sudo systemctl start varnishncsa

By default this integration provides two commands that enable frontend and backend logging capabilities. Since Varnish does not naturally record logs into a file, a log path must be specified for varnishncsa to write to. For darwin and linux systems respectively, the paths need to be /opt/varnish/log and /var/log/varnish. Note: replace <instance_name> and <log_path> with the respective names of the instance and log path. If there is only one instance, then the -n <instance_name> flag can be removed. The below commands must be re-run for each instance that log collection is required for.

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sudo varnishncsa -n <instance_name> -F '{"Timestamp": "%t", "Varnish-Side": "%{Varnish:side}x", "Age": %{age}o, "Handling": "%{Varnish:handling}x", "Request": "%r", "Status": "%s", "Response-Reason": "%{VSL:RespReason}x", "Fetch-Error": "%{VSL:FetchError}x", "X-Forwarded-For": "%{x-forwarded-for}i", "Remote-User": "%u", "Bytes": "%b", "Time-To-Serve": %D, "User-Agent": "%{User-agent}i", "Referer": "%{Referer}i", "X-Varnish": "%{x-varnish}o", "X-Magento-Tags": "%{x-magento-tags}o"}}' -D -w <log_path>/varnishncsa-frontend.log

sudo varnishncsa -n <instance_name> -b -F '{"Timestamp": "%t", "Varnish-Side": "%{Varnish:side}x", "Handling": "%{Varnish:handling}x", "Request": "%r", "Status": "%s", "Response-Reason": "%{VSL:RespReason}x", "Fetch-Error": "%{VSL:FetchError}x", "Bytes": "%b", "Time-To-Serve": %D}' -D -w <log_path>/varnishncsa-backend.log

For multiple instances, configure the files where logs are written to follow the following naming convention: varnishncsa-frontend-<instance_name>.log varnishncsa-backend-<instance_name>.log

Install Varnish Cache integration for Grafana Cloud

1. In your Grafana Cloud stack, click Connections in the left-hand menu.
2. Find Varnish Cache and click its tile to open the integration.
3. Review the prerequisites in the Configuration Details tab and set up Grafana Agent to send Varnish Cache metrics and logs to your Grafana Cloud instance.
4. Click Install to add this integration’s pre-built dashboard and alerts to your Grafana Cloud instance, and you can start monitoring your Varnish Cache setup.

Configuration snippets for Grafana Alloy

Advanced mode

The following snippets provide examples to guide you through the configuration process.

To instruct Grafana Alloy to scrape your Varnish Cache instances, manually copy and append the snippets to your alloy configuration file, then follow subsequent instructions.

Advanced metrics snippets

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discovery.relabel "metrics_integrations_integrations_varnish_cache" {
	targets = [{
		__address__ = "<exporter_host>:<exporter_port>",
	}]

	rule {
		target_label = "instance"
		replacement  = constants.hostname
	}
}

prometheus.scrape "metrics_integrations_integrations_varnish_cache" {
	targets    = discovery.relabel.metrics_integrations_integrations_varnish_cache.output
	forward_to = [prometheus.remote_write.metrics_service.receiver]
	job_name   = "integrations/varnish-cache"
}

To monitor your Varnish Cache instance, you must use a discovery.relabel component to discover your Varnish Cache Prometheus endpoint and apply appropriate labels, followed by a prometheus.scrape component to scrape it.

Configure the following properties within each discovery.relabel component:

• __address__: The address to your Varnish Cache Prometheus metrics endpoint.
• instance label: constants.hostname sets the instance label to your Grafana Alloy server hostname. If that is not suitable, change it to a value uniquely identifies this Varnish Cache instance. Make sure this label value is the same for all telemetry data collected for this instance.

If you have multiple Varnish Cache servers to scrape, configure one discovery.relabel for each and scrape them by including each under targets within the prometheus.scrape component.

Advanced logs snippets

darwin

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local.file_match "logs_integrations_integrations_varnish_cache" {
	path_targets = [{
		__address__ = "localhost",
		__path__    = "<log_path>/varnishncsa*.log",
		instance    = constants.hostname,
		job         = "integrations/varnish-cache",
	}]
}

loki.source.file "logs_integrations_integrations_varnish_cache" {
	targets    = local.file_match.logs_integrations_integrations_varnish_cache.targets
	forward_to = [loki.write.grafana_cloud_loki.receiver]
}

To monitor your Varnish Cache instance logs, you will use a combination of the following components:

• local.file_match defines where to find the log file to be scraped. Change the following properties according to your environment:

  • __address__: The Varnish Cache instance address
  • __path__: The path to the log file.
  • instance label: constants.hostname sets the instance label to your Grafana Alloy server hostname. If that is not suitable, change it to a value uniquely identifies this Varnish Cache instance. Make sure this label value is the same for all telemetry data collected for this instance.

• loki.source.file sends logs to Loki.

linux

river Copy

local.file_match "logs_integrations_integrations_varnish_cache" {
	path_targets = [{
		__address__ = "localhost",
		__path__    = "<log_path>/varnishncsa*.log",
		instance    = constants.hostname,
		job         = "integrations/varnish-cache",
	}]
}

loki.source.file "logs_integrations_integrations_varnish_cache" {
	targets    = local.file_match.logs_integrations_integrations_varnish_cache.targets
	forward_to = [loki.write.grafana_cloud_loki.receiver]
}

To monitor your Varnish Cache instance logs, you will use a combination of the following components:

• local.file_match defines where to find the log file to be scraped. Change the following properties according to your environment:

  • __address__: The Varnish Cache instance address
  • __path__: The path to the log file.
  • instance label: constants.hostname sets the instance label to your Grafana Alloy server hostname. If that is not suitable, change it to a value uniquely identifies this Varnish Cache instance. Make sure this label value is the same for all telemetry data collected for this instance.

• loki.source.file sends logs to Loki.

Before you begin

In order for the integration to properly work, you must set up the Varnish Cache exporter for Prometheus to export metrics from Varnish.

Set up Varnish Cache exporter

Install the version of the exporter that corresponds to your operating system. The latest releases and installs can be found on exporter installation. To start the exporter first unzip the file that you downloaded above and traverse to the directory where the executable is. The executable will be named similar to prometheus_varnish_exporter. An example of the exporter being run is shown below:

bash Copy

sudo ./prometheus_varnish_exporter

The above will run a

bash Copy

varnishstat -j

behind the scenes and open a port 9131 that can be accessed through localhost:9131. The exported Prometheus metrics can be seen at localhost:9131/metrics.

The exporter exposes port 9131 by default but you can change this using the -web.listen-address flag when running the exporter. The use of this flag would look like this:

bash Copy

sudo ./prometheus_varnish_exporter -web.listen-address localhost:9595

If you have multiple Varnish instances, you must specify which you are targeting with the exporter. This can be done by running the exporter with the flag -n and the name of your varnish instance. Example shown below:

bash Copy

sudo ./prometheus_varnish_exporter -n <instance_name>

This also means you would need one exporter for each instance of Varnish Cache, each with a unique port.

For more options and help with the exporter, you can run the below command:

bash Copy

sudo ./prometheus_varnish_exporter -h

Once deployed, the Grafana Agent should be able to reach the Varnish Cache exporter’s exposed endpoint in order to scrape metrics.

Set up Varnish Cache logging

This integration leverages the varnishncsa utility provided by Varnish in order to produce formatted logs. Any format of log collection with varnishncsa will be picked up by the integration.

In order to setup varnishncsa, the utility must be enabled by running:

bash Copy

sudo systemctl enable varnishncsa
sudo systemctl start varnishncsa

By default this integration provides two commands that enable frontend and backend logging capabilities. Since Varnish does not naturally record logs into a file, a log path must be specified for varnishncsa to write to. For darwin and linux systems respectively, the paths need to be /opt/varnish/log and /var/log/varnish. Note: replace <instance_name> and <log_path> with the respective names of the instance and log path. If there is only one instance, then the -n <instance_name> flag can be removed. The below commands must be re-run for each instance that log collection is required for.

bash Copy

sudo varnishncsa -n <instance_name> -F '{"Timestamp": "%t", "Varnish-Side": "%{Varnish:side}x", "Age": %{age}o, "Handling": "%{Varnish:handling}x", "Request": "%r", "Status": "%s", "Response-Reason": "%{VSL:RespReason}x", "Fetch-Error": "%{VSL:FetchError}x", "X-Forwarded-For": "%{x-forwarded-for}i", "Remote-User": "%u", "Bytes": "%b", "Time-To-Serve": %D, "User-Agent": "%{User-agent}i", "Referer": "%{Referer}i", "X-Varnish": "%{x-varnish}o", "X-Magento-Tags": "%{x-magento-tags}o"}}' -D -w <log_path>/varnishncsa-frontend.log

sudo varnishncsa -n <instance_name> -b -F '{"Timestamp": "%t", "Varnish-Side": "%{Varnish:side}x", "Handling": "%{Varnish:handling}x", "Request": "%r", "Status": "%s", "Response-Reason": "%{VSL:RespReason}x", "Fetch-Error": "%{VSL:FetchError}x", "Bytes": "%b", "Time-To-Serve": %D}' -D -w <log_path>/varnishncsa-backend.log

For multiple instances, configure the files where logs are written to follow the following naming convention: varnishncsa-frontend-<instance_name>.log varnishncsa-backend-<instance_name>.log

Install Varnish Cache integration for Grafana Cloud

1. In your Grafana Cloud stack, click Connections in the left-hand menu.
2. Find Varnish Cache and click its tile to open the integration.
3. Review the prerequisites in the Configuration Details tab and set up Grafana Agent to send Varnish Cache metrics and logs to your Grafana Cloud instance.
4. Click Install to add this integration’s pre-built dashboard and alerts to your Grafana Cloud instance, and you can start monitoring your Varnish Cache setup.

Post-install configuration for the Varnish Cache integration

After enabling the metrics generation, instruct the Grafana Agent to scrape your Varnish Cache metrics.

The exporter exposes a default Prometheus endpoint route in the /metrics format endpoint. To scrape it, add the snippet in the next step to your agent configuration file.

Make sure to change targets in the snippet according to your environment.

If you want to show logs and metrics signals correlated in your dashboards as a single pane of glass, ensure the following:

• job and instance label values must match for the Varnish Cache integration and logs scrape config in your agent configuration file.
• job label must be set to integrations/varnish-cache (already configured in the snippets)
• instance label must be set to a value that uniquely identifies your Varnish Cache instance. Please replace the default varnish_host value according to your environment - it should be set manually. Note that if you use localhost for multiple instances, the dashboards will not be able to filter correctly by instance.

Configuration snippets for Grafana Agent

Below metrics.configs.scrape_configs, insert the following lines and change the URLs according to your environment:

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    - job_name: integrations/varnish-cache
      metrics_path: /metrics
      relabel_configs:
        - replacement: '<your-instance-name>'
          target_label: instance
      static_configs: 
        - targets:
          - '<exporter_host>:<exporter_port>'

Below logs.configs.scrape_configs, insert the following lines according to your environment.

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    - job_name: integrations/varnish-cache
      static_configs:
        - targets: [localhost] 
          labels:
            job: integrations/varnish-cache
            instance: '<your-instance-name>'
            __path__: '<log_path>/varnishncsa*.log'

Full example configuration for Grafana Agent

Refer to the following Grafana Agent configuration for a complete example that contains all the snippets used for the Varnish Cache integration. This example also includes metrics that are sent to monitor your Grafana Agent instance.

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integrations:
  prometheus_remote_write:
  - basic_auth:
      password: <your_prom_pass>
      username: <your_prom_user>
    url: <your_prom_url>
  agent:
    enabled: true
    relabel_configs:
    - action: replace
      source_labels:
      - agent_hostname
      target_label: instance
    - action: replace
      target_label: job
      replacement: "integrations/agent-check"
    metric_relabel_configs:
    - action: keep
      regex: (prometheus_target_sync_length_seconds_sum|prometheus_target_scrapes_.*|prometheus_target_interval.*|prometheus_sd_discovered_targets|agent_build.*|agent_wal_samples_appended_total|process_start_time_seconds)
      source_labels:
      - __name__
  # Add here any snippet that belongs to the `integrations` section.
  # For a correct indentation, paste snippets copied from Grafana Cloud at the beginning of the line.
logs:
  configs:
  - clients:
    - basic_auth:
        password: <your_loki_pass>
        username: <your_loki_user>
      url: <your_loki_url>
    name: integrations
    positions:
      filename: /tmp/positions.yaml
    scrape_configs:
      # Add here any snippet that belongs to the `logs.configs.scrape_configs` section.
      # For a correct indentation, paste snippets copied from Grafana Cloud at the beginning of the line.
    - job_name: integrations/varnish-cache
      static_configs:
        - targets: [localhost] 
          labels:
            job: integrations/varnish-cache
            instance: '<your-instance-name>'
            __path__: '<log_path>/varnishncsa*.log'
metrics:
  configs:
  - name: integrations
    remote_write:
    - basic_auth:
        password: <your_prom_pass>
        username: <your_prom_user>
      url: <your_prom_url>
    scrape_configs:
      # Add here any snippet that belongs to the `metrics.configs.scrape_configs` section.
      # For a correct indentation, paste snippets copied from Grafana Cloud at the beginning of the line.
    - job_name: integrations/varnish-cache
      metrics_path: /metrics
      relabel_configs:
        - replacement: '<your-instance-name>'
          target_label: instance
      static_configs: 
        - targets:
          - '<exporter_host>:<exporter_port>'
  global:
    scrape_interval: 60s
  wal_directory: /tmp/grafana-agent-wal