Envoy standalone DaemonSet does not pick up IPCache changes after cilium-agent restart #32651
Description
Is there an existing issue for this?
- I have searched the existing issues
What happened?
When using a L7-HTTP policy in combination with ToFQDN and Cilium is restarted, Envoy denies access to IPs which should be allowlisted. Presumably this happens because the stanadalone DaemonSet does not pick up the new IPCache BPF map.
Steps to reproduce
- Install Cilium with the standalone Envoy DaemonSet:
helm install --upgrade cilium cilium/cilium -n kube-system --set debug.enabled=true --set envoy.enabled=true
- Deploy the
cilium connectivity testpods - Deploy a policy which combines L7 rules with dynamic L4 targets (in this example, we're using FQDN):
apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
name: client-egress-to-fqdns
spec:
endpointSelector:
matchLabels:
kind: client
egress:
- toPorts:
- ports:
- port: "80"
protocol: TCP
rules:
http:
- method: "GET"
path: "/"
toFQDNs:
- matchPattern: "*.io"
- matchPattern: "*.com"
- toPorts:
- ports:
- port: "53"
protocol: UDP
- port: "53"
protocol: TCP
rules:
dns:
- matchPattern: "*"
toEndpoints:
- matchExpressions:
- { key: 'k8s-app', operator: In, values: [ "kube-dns", "coredns", "node-local-dns", "nodelocaldns" ] }
- { key: 'io.kubernetes.pod.namespace', operator: In, values: [ "kube-system" ] }
- Run a test query or two to validate that everything is set up
$ kubectl -n cilium-test exec -ti client-59c486cb54-mwslp -- curl isovalent.com
Redirecting to https://isovalent.com/
$ kubectl -n cilium-test exec -ti client-59c486cb54-mwslp -- curl cilium.io
Redirecting to https://cilium.io/- Restart cilium-agent. This will create a new IPCache map with restored CIDR entries from the old one
- Observe that new target domains result in
Access deniedfrom Envoy, where as old (restored) entries still work
$ kubectl -n cilium-test exec -ti client-59c486cb54-mwslp -- curl isovalent.com # still allowed as before
Redirecting to https://isovalent.com/
$ kubectl -n cilium-test exec -ti client-59c486cb54-mwslp -- curl cilium.io # still allowed as before
Redirecting to https://cilium.io/
$ kubectl -n cilium-test exec -ti client-59c486cb54-mwslp -- curl google.com # BUG: denied, but this should be allowed!
Access deniedHubble also confirms that this was denied by Envoy:
May 21 14:54:47.056: cilium-test/client-59c486cb54-mwslp:53580 (ID:61922) -> google.com:80 (world-ipv4) http-request DROPPED (HTTP/1.1 GET http://google.com/)
May 21 14:54:47.056: cilium-test/client-59c486cb54-mwslp:53580 (ID:61922) <- google.com:80 (world-ipv4) http-response FORWARDED (HTTP/1.1 403 0ms (GET http://google.com/))
I've manually checked and the google.com IP was added to IPCache as part of the FQDN lookup. However, Envoy (as evident in it's debug logs and Hubble) instead assigns identity 9 ("world-ipv4"), indicating that it did not find the IP in IPCache. Presumably because it's still using the pre-restart version of IPCache
Side-note: The issue can be resolved by restarting the cilium-envoy DaemonSet. Presumably this causes the Envoy DaemonSet to pick up the proper IPCache map
$ kubectl -n kube-system rollout restart daemonset cilium-envoy
$ kubectl -n cilium-test exec -ti client-59c486cb54-mwslp -- curl google.com
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</BODY></HTML>Cilium Version
Reproduced on v1.15.5 and main (2024-05-21)
Kernel Version
n/a
Kubernetes Version
n/a
Regression
Marked as release blocker for v1.16 as it makes the Envoy DaemonSet the default
Sysdump
No response
Relevant log output
No response
Anything else?
No response
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