Pre-check incorrectly highlighting IST0169

[Stono]

Is this the right place to submit this?

• This is not a security vulnerability or a crashing bug
• This is not a question about how to use Istio

Bug Description

Using the new precheck command we get:

Warning [IST0169] (DestinationRule zendesk-controller/zendesk) The configuration "VERIFY_CERTIFICATE_AT_CLIENT" changed in release 1.20: previously, TLS verification was skipped. Set `insecureSkipVerify` if this behavior is desired. Or, install with `--set compatibilityVersion=1.20` to retain the old default.

On our destinationrule we explicitly set:

      tls:
        caCertificates: /etc/ssl/certs/ca-certificates.crt
        mode: SIMPLE
        sni: whatever.zendesk.com

My understanding was that this implicitly enabled TLS verification, so this warning feels incorrect?

Version

1.21.0

Additional Information

No response

[howardjohn]

istio/istioctl/pkg/precheck/precheck.go

Lines 187 to 190 in 4246548

	checkVerify := func(tls *networking.ClientTLSSettings) bool {
	return tls != nil && tls.CaCertificates == "" && tls.CredentialName == "" &&
	tls.Mode != networking.ClientTLSSettings_ISTIO_MUTUAL && !tls.InsecureSkipVerify.GetValue()
	}

is the logic. I would think that is NOT impacted and should not log.

However, the TLS config can be in 4 places: {main,subset}x{global,port level}.. maybe one of them? Do you have the full DR so I can test?

[howardjohn]

$ ./istio-1.21.0/bin/istioctl x precheck  --from-version 1.20
✔ No issues found when checking the cluster. Istio is safe to install or upgrade!
  To get started, check out https://istio.io/latest/docs/setup/getting-started/

with

apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: bookinfo-ratings
spec:
  host: ratings.prod.svc.cluster.local
  trafficPolicy:
    loadBalancer:
      simple: LEAST_REQUEST
    tls:
      caCertificates: /etc/ssl/certs/ca-certificates.crt
      mode: SIMPLE
      sni: whatever.zendesk.com

[Stono]

Ah it's because it's a complex DR (as we're doing tls origination) under portLevelSettings:

apiVersion: networking.istio.io/v1beta1
kind: DestinationRule
metadata:
  name: zendesk
  namespace: zendesk-controller
spec:
  exportTo:
  - .
  host: autotraderukpreprod.zendesk.com
  trafficPolicy:
    connectionPool:
      http:
        h2UpgradePolicy: DO_NOT_UPGRADE
      tcp:
        connectTimeout: 2s
        maxConnectionDuration: 5m
        tcpKeepalive:
          interval: 30s
          time: 30s
    portLevelSettings:
    - connectionPool:
        http:
          h2UpgradePolicy: DO_NOT_UPGRADE
        tcp:
          connectTimeout: 2s
          maxConnectionDuration: 5m
          tcpKeepalive:
            interval: 30s
            time: 30s
      port:
        number: 443
      tls:
        mode: DISABLE
    - connectionPool:
        http:
          h2UpgradePolicy: DO_NOT_UPGRADE
        tcp:
          connectTimeout: 2s
          maxConnectionDuration: 5m
          tcpKeepalive:
            interval: 30s
            time: 30s
      port:
        number: 80
      tls:
        caCertificates: /etc/ssl/certs/ca-certificates.crt
        mode: SIMPLE
        sni: autotraderukpreprod.zendesk.com

[howardjohn]

thanks! i'll send a fix