This module is responsible for providing a network between multiple nodes in a cluster using the cilium module.
Limitations
- This module currently supports only direct-routing mode.
- Service types
NodePort
andLoadBalancer
do not work with hostNetwork endpoints in theDSR
LB mode. Switch toSNAT
if it is required. HostPort
Pods will bind only to one interface IP. If there are multiple interfaces/IPs present, Cilium will select only one of them, preferring private IP space.- OS versions support.
cni-cilium
module will properly work only on Linux kernel >=5.3
.
A note about CiliumClusterwideNetworkPolicies
- Make sure that you deploy initial set of CiliumClusterwideNetworkPolicies with
policyAuditMode
configuration options set totrue
. Otherwise you are degrading cluster operation or even completely losing SSH connectivity to all Kubernetes Nodes. You can remove the option once allCiliumClusterwideNetworkPolicy
objects are applied and you’ve verified their effect in the Hubble UI. -
Make sure to deploy the following rule, otherwise control-plane will fail for up to 1 minute on
cilium-agent
restart. This happens due to conntrack table reset. Referencingkube-apiserver
entity helps us to “circumvent” the bug.apiVersion: "cilium.io/v2" kind: CiliumClusterwideNetworkPolicy metadata: name: "allow-control-plane-connectivity" spec: ingress: - fromEntities: - kube-apiserver nodeSelector: matchLabels: node-role.kubernetes.io/control-plane: ""
A note about Cilium work mode change
If you change the Cilium operating mode (the tunnelMode parameter) from Disabled
to VXLAN
or vice versa, you must restart all nodes, otherwise there may be problems with the availability of Pods.