I know this is old, but New Relic has ARM and ARM64 infrastructure agents now:
https://download.newrelic.com/infrastructure_agent/binaries/linux/arm/
I've tested this on a Raspberry Pi 4 (8GB) on Debian (32-bit) and it's been working fine so far.
In case anyone else tries, here's what I did:
Download the Infrastructure Agent:
sudo curl https://download.newrelic.com/infrastructure_agent/binaries/linux/arm/newrelic-infra_linux_1.20.5_arm.tar.gz --output newrelic-infra_linux_1.20.5_arm.tar.gz
Extract the files
sudo tar -xf newrelic-infra_linux_1.20.5_arm.tar.gz
Add license key to the config script:
echo "license_key=\"<YOUR_LICENSE_KEY>\"" | sudo tee -a ~/newrelic-infra/config_defaults.sh
Install the Infrastructure Agent
sudo ~/newrelic-infra/installer.sh
Check service status to make sure it's running:
sudo systemctl status newrelic-infra
By default, process information is not sent to New Relic, so I had to enable it manually:
echo "enable_process_metrics: true" | sudo tee -a /etc/newrelic-infra.yml
Finally, restart the service:
sudo systemctl restart newrelic-infra