a5edd0d709
* [jjo] add kube-router support Fixes cloudnativelabs/kube-router#147. * add kube-router as another network_plugin choice * support most used kube-router flags via `kube_router_foo` vars as other plugins * implement replacing kube-proxy (--run-service-proxy=true) via `kube_proxy_mode: none`, verified in a _non kubeadm_enabled_ install, should also work for recent kubeadm releases via `skipKubeProxyInstall: true` config * [jjo] address PR#3339 review from @woopstar * add busybox image used by kube-router to downloads * fix busybox download groups key * rework kubeadm_enabled + kube_router_run_service_proxy - verify it working ok w/the kubeadm_enabled and kube_router_run_service_proxy true or false - introduce `kube_proxy_remove` fact, to decouple logic from kube_proxy_mode (which affects kubeadm configmap settings, thus no-good to ab-use it to 'none') * improve kube-router.md re: kubeadm_enabled and kube_router_run_service_proxy * address @woopstar latest review * add inventory/sample/group_vars/k8s-cluster/k8s-net-kube-router.yml * fix kube_router_run_service_proxy conditional for kube-proxy removal * fix kube_proxy_remove fact (w/ |bool), add some needed kube-proxy tags on my and existing changes * update kube-router tolerations for 1.12 compatibility * add PriorityClass to kube-router DaemonSet
91 lines
3.5 KiB
Markdown
91 lines
3.5 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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