Getting Envoy's Access Logs

The simplest kind of Istio logging is Envoy’s access logging¹. 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.

Before you begin

• Setup Istio by following the instructions in the Installation guide².

• Deploy the sleep³ sample app to use as a test source for sending requests. If you have automatic sidecar injection enabled, run the following command to deploy the sample app:

  Zip

  $ kubectl apply -f samples/sleep/sleep.yaml4
  

  Otherwise, manually inject the sidecar before deploying the sleep application with the following command:

  Zip

  $ kubectl apply -f <(istioctl kube-inject -f samples/sleep/sleep.yaml4)
  

• Set the SOURCE_POD environment variable to the name of your source pod:

  $ export SOURCE_POD=$(kubectl get pod -l app=sleep -o jsonpath={.items..metadata.name})
  

• Start the httpbin⁵ sample.

  If you have enabled automatic sidecar injection, deploy the httpbin service:

  Zip

  $ kubectl apply -f samples/httpbin/httpbin.yaml6
  

  Otherwise, you have to manually inject the sidecar before deploying the httpbin application:

  Zip

  $ kubectl apply -f <(istioctl kube-inject -f samples/httpbin/httpbin.yaml6)
  

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 format⁷ 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 information⁷.

Cleanup

Shutdown the sleep³ and httpbin⁵ services:

$ kubectl delete -f samples/sleep/sleep.yaml4
$ kubectl delete -f samples/httpbin/httpbin.yaml6

Disable Envoy’s access logging

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

$ istioctl manifest apply
configmap "istio" replaced