AKS: avoid overlapping pod and service CIDRs #31504
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The default service CIDR of AKS clusters is 10.0.0.0/16 [1]. Unfortunately, we don't set a pod cidr for clusterpool IPAM, and hence use cilium's default of 10.0.0.0/8, which overlaps. This can lead to "fun" situations in which e.g. the kube-dns service ClusterIP is the same as the hubble-relay pod IP, or similar shenanigans. This usually breaks the cluster utterly. The fix is relatively straight-forward: set a pod CIDR for cilium which does not overlap with defaults of AKS. We chose 192.168.0.0/16 as this is what is recommended in [2]. [1]: https://learn.microsoft.com/en-us/azure/aks/configure-kubenet#create-an-aks-cluster-with-system-assigned-managed-identities [2]: https://learn.microsoft.com/en-us/azure/aks/azure-cni-powered-by-cilium#option-1-assign-ip-addresses-from-an-overlay-network Fixes: fbf3d38 (ci: add AKS workflow) Co-authored-by: Fabian Fischer <fabian.fischer@isovalent.com> Signed-off-by: David Bimmler <david.bimmler@isovalent.com>
bimmlerd
added
kind/bug/CI
|
/ci-aks |
|
/test |
maintainer-s-little-helper
bot
added
the
ready-to-merge
|
@viktor-kurchenko I don't know enough about our CI to know whether this should be backported or not - are these workflows run from Also, do we have this bug on other cloud providers? Seems like an easy oversight to make. Finally, this probably also wants to be documented somewhere? |
giorio94
added
needs-backport/1.13
Marked for backport to all stable branches, as run from the respective workflow files. |
@bimmlerd sorry for the delay. To be honest I don't where we can document this ( |
tklauser
added a commit
to cilium/cilium-cli
that referenced
this pull request
Mar 22, 2024
Follow cilium/cilium#31504, quoting its commit description: > The default service CIDR of AKS clusters is 10.0.0.0/16 [1]. > Unfortunately, we don't set a pod cidr for clusterpool IPAM, and hence > use cilium's default of 10.0.0.0/8, which overlaps. This can > lead to "fun" situations in which e.g. the kube-dns service ClusterIP is > the same as the hubble-relay pod IP, or similar shenanigans. This > usually breaks the cluster utterly. > > The fix is relatively straight-forward: set a pod CIDR for cilium which > does not overlap with defaults of AKS. We chose 192.168.0.0/16 as this > is what is recommended in [2]. > > [1]: https://learn.microsoft.com/en-us/azure/aks/configure-kubenet#create-an-aks-cluster-with-system-assigned-managed-identities > [2]: https://learn.microsoft.com/en-us/azure/aks/azure-cni-powered-by-cilium#option-1-assign-ip-addresses-from-an-overlay-network Co-authored-by: Fabian Fischer <fabian.fischer@isovalent.com> Co-authored-by: David Bimmler <david.bimmler@isovalent.com> Signed-off-by: Tobias Klauser <tobias@cilium.io>
sayboras
added
backport-pending/1.15
sayboras
added
the
backport-pending/1.14
sayboras
removed
the
needs-backport/1.14
sayboras
added
backport-pending/1.13
github-actions
bot
added
backport-done/1.13
tklauser
added a commit
to cilium/cilium-cli
that referenced
this pull request
Mar 26, 2024
Follow cilium/cilium#31504, quoting its commit description: > The default service CIDR of AKS clusters is 10.0.0.0/16 [1]. > Unfortunately, we don't set a pod cidr for clusterpool IPAM, and hence > use cilium's default of 10.0.0.0/8, which overlaps. This can > lead to "fun" situations in which e.g. the kube-dns service ClusterIP is > the same as the hubble-relay pod IP, or similar shenanigans. This > usually breaks the cluster utterly. > > The fix is relatively straight-forward: set a pod CIDR for cilium which > does not overlap with defaults of AKS. We chose 192.168.0.0/16 as this > is what is recommended in [2]. > > [1]: https://learn.microsoft.com/en-us/azure/aks/configure-kubenet#create-an-aks-cluster-with-system-assigned-managed-identities > [2]: https://learn.microsoft.com/en-us/azure/aks/azure-cni-powered-by-cilium#option-1-assign-ip-addresses-from-an-overlay-network Co-authored-by: Fabian Fischer <fabian.fischer@isovalent.com> Co-authored-by: David Bimmler <david.bimmler@isovalent.com> Signed-off-by: Tobias Klauser <tobias@cilium.io>
tklauser
added a commit
to cilium/cilium-cli
that referenced
this pull request
Mar 26, 2024
Follow cilium/cilium#31504, quoting its commit description: > The default service CIDR of AKS clusters is 10.0.0.0/16 [1]. > Unfortunately, we don't set a pod cidr for clusterpool IPAM, and hence > use cilium's default of 10.0.0.0/8, which overlaps. This can > lead to "fun" situations in which e.g. the kube-dns service ClusterIP is > the same as the hubble-relay pod IP, or similar shenanigans. This > usually breaks the cluster utterly. > > The fix is relatively straight-forward: set a pod CIDR for cilium which > does not overlap with defaults of AKS. We chose 192.168.0.0/16 as this > is what is recommended in [2]. > > [1]: https://learn.microsoft.com/en-us/azure/aks/configure-kubenet#create-an-aks-cluster-with-system-assigned-managed-identities > [2]: https://learn.microsoft.com/en-us/azure/aks/azure-cni-powered-by-cilium#option-1-assign-ip-addresses-from-an-overlay-network Co-authored-by: Fabian Fischer <fabian.fischer@isovalent.com> Co-authored-by: David Bimmler <david.bimmler@isovalent.com> Signed-off-by: Tobias Klauser <tobias@cilium.io>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The default service CIDR of AKS clusters is 10.0.0.0/16 1. Unfortunately, we don't set a pod cidr for clusterpool IPAM, and hence use cilium's default of 10.0.0.0/8, which overlaps. This can lead to "fun" situations in which e.g. the kube-dns service ClusterIP is the same as the hubble-relay pod IP, or similar shenanigans. This usually breaks the cluster utterly.
The fix is relatively straight-forward: set a pod CIDR for cilium which does not overlap with defaults of AKS. We chose 192.168.0.0/16 as this is what is recommended in 2.
Fixes: fbf3d38 (ci: add AKS workflow)
Fixes: #30905