istio - enabling debugging

Normally we would be able to do it using the following yaml 

apiVersion: install.istio.io/v1

kind: IstioOperator

metadata:

  name: istio-default

  namespace: istio-system

spec:

  meshConfig:

    accessLogFile: /dev/stdout

 

But sometimes we dont have istio operator crds install on our local testing cluster. So to quicky enable logging, we can do this accessLogFile to dev/stdout as shown here:- 

kubectl -n istio-system edit configmap istio

And ensure we set

apiVersion: v1

data:

  mesh: |-

    defaultConfig:

      discoveryAddress: istiod.istio-system.svc:15012

    defaultProviders:

      metrics:

      - prometheus

    enablePrometheusMerge: true

    rootNamespace: istio-system

    trustDomain: cluster.local

    accessLogFile: /dev/stdout

    accessLogFormat: |

        [%START_TIME%] "%REQ(:METHOD)% %REQ(X-ENVOY-ORIGINAL-PATH?:PATH)% %PROTOCOL%"

        %RESPONSE_CODE% %RESPONSE_FLAGS% %RESPONSE_CODE_DETAILS%

        "%UPSTREAM_HOST%" %BYTES_RECEIVED% %BYTES_SENT%

  meshNetworks: 'networks: {}'

And then restart istio

kubectl rollout restart deploy -n istio-system istiod

kubectl rollout restart deploy -n istio-system istio-ingressgateway

kubectl rollout restart deploy -n istio-system istio-egressgateway

You can enable debuggin on the pod level by running the command 

istioctl proxy-config log  <pod>  --level debug

We can also do this 

kubectl exec -n istio-system deploy/istiod -c discovery -- \

  curl -X POST "localhost:15014/debug?level=debug"