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kubernetesmetallb

Unable to get metallb working on my bare-metal cluster

I have a bare metal cluster with 3 servers which are publicly available but each one has a totally different ip address. I have my DNS entry to point to all 3 hosts - so traffic can received by any host. I have all of them connected via a vlan. Now I would like that traffic coming from internet is forwarded to the k8s node, where the service is running:


browse "mysrv.mydomain.com"
             |
          .-~|~-.
  .- ~ ~-(   |   )_ _
 /           v         ~ -.
|            |              \
 \           |             .'
   ~- . _____|_______ . -~
             |
             |  request can go to any service
             |
             +----------->--------------+------------>-------------+
             v                          v                          v
             |                          |                          |
             |                          |                          |
  +---------------------+    +---------------------+    +---------------------+
  |        host01       |    |        host02       |    |        host03       |
  |      k8s master     |    |       k8s node      |    |       k8s node      |
  |                     |    |                     |    |                     |
  | Pub.Ip: x.x.x.x     |    | Pub.Ip: y.y.y.y     |    | Pub.Ip: z.z.z.z     |
  |                     |    |                     |    |                     |
  | VlanIp: 192.168.0.1 |----| VlanIp: 192.168.0.2 |----| VlanIp: 192.168.0.3 |
  +---------------------+    +---------------------+    +---------------------+

I understand that I have to use metallb, thus I followed the setup description here: https://kubernetes.github.io/ingress-nginx/deploy/baremetal/#a-pure-software-solution-metallb. I can successfully deploy the nginx load balancer but I am not user how to configure metallb.

apiVersion: v1
kind: ConfigMap
metadata:
  namespace: metallb-system
  name: config
data:
  config: |
    address-pools:
    - name: default
      protocol: layer2
      addresses:
      - x.x.x.x,y.y.y.y,z.z.z.z
    - name: internal
      protocol: layer2
      addresses:
      - 192.168.0.200-192.168.0.210

Using default results in a nginx services which never gets an external Ip

> kubectl get svc -n ingress-nginx ingress-nginx 
NAME            TYPE           CLUSTER-IP       EXTERNAL-IP   PORT(S)                      AGE
ingress-nginx   LoadBalancer   10.107.136.170   <pending>     80:30152/TCP,443:30276/TCP   43h

Using internal works but only when I am connected to the internal vlan.

Any hint would be useful on how I can make my scenario work.

Solution

  • Your environment is not a good fit for MetalLB - you would need IPs that can be assigned to any node (floating IP / service IP). For your situation a reverse proxy, which is called Ingress in Kubernetes, would be a better solution.