This article details how to enable Envoy’s access logging, for Rancher deployed Istio, in Rancher v2.3+

Pre-requisites

To enable Access loggings for Envoy, Rancher deployed Istio by setting the global.proxy.accessLogFile path and global.proxy.accessLogEncoding type via Custom Answers on the Istio configuration.

Setting the accessLogFile path to /dev/stdout will route the Envoy access logs to the istio-sidecar container logs, exposing them via kubectl logs or any log forwarding endpoint you have configured in the cluster.

The log format, specified in accessLogEncoding, can be set to JSON or TEXT.

To enable access logging, perform the following steps:

  • Navigate to the cluster view in the Rancher UI for the desired cluster and select Tools > Istio.

  • Under the Custom Answers section, enter the following two value pairs and click Save or Enable (the option will depend on whether you have Istio enabled in the cluster already):

    global.proxy.accessLogFile=/dev/stdout
    global.proxxy.accessLogEncoding=JSON
    
  • After enabling access logging, you can test the configuration with the Istio sleep and httpbin sample applications, per the Istio documentation.

Further reading