Getting Envoy's Access Logs

The simplest kind of Istio logging is Envoy's access logging. Envoy proxies print access information to their standard output. The standard output of Envoy's containers can then be printed by the kubectl logs command.

Enable Envoy's access logging

Edit the istio configuration map:

$ istioctl manifest apply --set values.global.proxy.accessLogFile="/dev/stdout"
configmap "istio" replaced

You can also choose between JSON and text by setting accessLogEncoding to JSON or TEXT.

You may also want to customize the format of the access log by editing accessLogFormat.

  • global.proxy.accessLogFile
  • global.proxy.accessLogEncoding
  • global.proxy.accessLogFormat

Test the access log

  1. Send a request from sleep to httpbin:

    $ kubectl exec -it $(kubectl get pod -l app=sleep -o jsonpath='{.items[0].metadata.name}') -c sleep -- curl -v httpbin:8000/status/418
    *   Trying 172.21.13.94...
    * TCP_NODELAY set
    * Connected to httpbin (172.21.13.94) port 8000 (#0)
    > GET /status/418 HTTP/1.1
    
    ...
    < HTTP/1.1 418 Unknown
    < server: envoy
    ...
    
        -=[ teapot ]=-
    
           _...._
         .'  _ _ `.
        | ."` ^ `". _,
        \_;`"---"`|//
          |       ;/
          \_     _/
            `"""`
    * Connection #0 to host httpbin left intact
    
  2. Check sleep's log:

    $ kubectl logs -l app=sleep -c istio-proxy
    [2019-03-06T09:31:27.354Z] "GET /status/418 HTTP/1.1" 418 - "-" 0 135 11 10 "-" "curl/7.60.0" "d209e46f-9ed5-9b61-bbdd-43e22662702a" "httpbin:8000" "172.30.146.73:80" outbound|8000||httpbin.default.svc.cluster.local - 172.21.13.94:8000 172.30.146.82:60290 -
    
  3. Check httpbin's log:

    $ kubectl logs -l app=httpbin -c istio-proxy
    [2019-03-06T09:31:27.360Z] "GET /status/418 HTTP/1.1" 418 - "-" 0 135 5 2 "-" "curl/7.60.0" "d209e46f-9ed5-9b61-bbdd-43e22662702a" "httpbin:8000" "127.0.0.1:80" inbound|8000|http|httpbin.default.svc.cluster.local - 172.30.146.73:80 172.30.146.82:38618 outbound_.8000_._.httpbin.default.svc.cluster.local
    

Note that the messages corresponding to the request appear in logs of the Istio proxies of both the source and the destination, sleep and httpbin, respectively. You can see in the log the HTTP verb (GET), the HTTP path (/status/418), the response code (418) and other request-related information.

Cleanup

Shutdown the sleep and httpbin services:

ZipZip
$ kubectl delete -f @samples/sleep/sleep.yaml@
$ kubectl delete -f @samples/httpbin/httpbin.yaml@

Disable Envoy's access logging

Edit the istio configuration map and set accessLogFile to "".

$ istioctl manifest apply
configmap "istio" replaced
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