108 lines
No EOL
4.2 KiB
Markdown
108 lines
No EOL
4.2 KiB
Markdown
Kube-router
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===========
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Kube-router is a L3 CNI provider, as such it will setup IPv4 routing between
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nodes to provide Pods' networks reachability.
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See [kube-router documentation](https://www.kube-router.io/).
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## Verifying kube-router install
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Kube-router runs its pods as a `DaemonSet` in the `kube-system` namespace:
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* Check the status of kube-router pods
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```
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# From the CLI
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kubectl get pod --namespace=kube-system -l k8s-app=kube-router -owide
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# output
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NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE
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kube-router-4f679 1/1 Running 0 2d 192.168.186.4 mykube-k8s-node-nf-2 <none>
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kube-router-5slf8 1/1 Running 0 2d 192.168.186.11 mykube-k8s-node-nf-3 <none>
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kube-router-lb6k2 1/1 Running 0 20h 192.168.186.14 mykube-k8s-node-nf-6 <none>
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kube-router-rzvrb 1/1 Running 0 20h 192.168.186.17 mykube-k8s-node-nf-4 <none>
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kube-router-v6n56 1/1 Running 0 2d 192.168.186.6 mykube-k8s-node-nf-1 <none>
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kube-router-wwhg8 1/1 Running 0 20h 192.168.186.16 mykube-k8s-node-nf-5 <none>
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kube-router-x2xs7 1/1 Running 0 2d 192.168.186.10 mykube-k8s-master-1 <none>
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```
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* Peek at kube-router container logs:
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```
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# From the CLI
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kubectl logs --namespace=kube-system -l k8s-app=kube-router | grep Peer.Up
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# output
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time="2018-09-17T16:47:14Z" level=info msg="Peer Up" Key=192.168.186.6 State=BGP_FSM_OPENCONFIRM Topic=Peer
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time="2018-09-17T16:47:16Z" level=info msg="Peer Up" Key=192.168.186.11 State=BGP_FSM_OPENCONFIRM Topic=Peer
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time="2018-09-17T16:47:46Z" level=info msg="Peer Up" Key=192.168.186.10 State=BGP_FSM_OPENCONFIRM Topic=Peer
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time="2018-09-18T19:12:24Z" level=info msg="Peer Up" Key=192.168.186.14 State=BGP_FSM_OPENCONFIRM Topic=Peer
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time="2018-09-18T19:12:28Z" level=info msg="Peer Up" Key=192.168.186.17 State=BGP_FSM_OPENCONFIRM Topic=Peer
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time="2018-09-18T19:12:38Z" level=info msg="Peer Up" Key=192.168.186.16 State=BGP_FSM_OPENCONFIRM Topic=Peer
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[...]
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```
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## Gathering kube-router state
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Kube-router Pods come bundled with a "Pod Toolbox" which provides very
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useful internal state views for:
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* IPVS: via `ipvsadm`
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* BGP peering and routing info: via `gobgp`
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You need to `kubectl exec -it ...` into a kube-router container to use these, see
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<https://www.kube-router.io/docs/pod-toolbox/> for details.
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## Kube-router configuration
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You can change the default configuration by overriding `kube_router_...` variables
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(as found at `roles/network_plugin/kube-router/defaults/main.yml`),
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these are named to follow `kube-router` command-line options as per
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<https://www.kube-router.io/docs/user-guide/#try-kube-router-with-cluster-installers>.
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## Caveats
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### kubeadm_enabled: true
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If you want to set `kube-router` to replace `kube-proxy`
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(`--run-service-proxy=true`) while using `kubeadm_enabled`,
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then 'kube-proxy` DaemonSet will be removed *after* kubeadm finishes
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running, as it's not possible to skip kube-proxy install in kubeadm flags
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and/or config, see https://github.com/kubernetes/kubeadm/issues/776.
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Given above, if `--run-service-proxy=true` is needed it would be
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better to void `kubeadm_enabled` i.e. set:
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```
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kubeadm_enabled: false
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kube_router_run_service_proxy: true
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```
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If for some reason you do want/need to set `kubeadm_enabled`, removing
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it afterwards behave better if kube-proxy is set to ipvs mode, i.e. set:
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```
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kubeadm_enabled: true
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kube_router_run_service_proxy: true
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kube_proxy_mode: ipvs
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```
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## Advanced BGP Capabilities
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https://github.com/cloudnativelabs/kube-router#advanced-bgp-capabilities
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If you have other networking devices or SDN systems that talk BGP, kube-router will fit in perfectly.
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From a simple full node-to-node mesh to per-node peering configurations, most routing needs can be attained.
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The configuration is Kubernetes native (annotations) just like the rest of kube-router.
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For more details please refer to the https://github.com/cloudnativelabs/kube-router/blob/master/docs/bgp.md.
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Next options will set up annotations for kube-router, using `kubectl annotate` command.
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```
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kube_router_annotations_master: []
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kube_router_annotations_node: []
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kube_router_annotations_all: []
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``` |