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Version: v1.1

Raven

This document introduces how to install raven and use raven to enhance edge-edge and edge-cloud network communication in an edge cluster.

Suppose you have an edge kubernetes cluster with nodes in different physical regions, and already deploy the Raven Controller Manager in this cluster, the details of Raven Controller Manager are in here.

Label nodes in different physical regions​

As follows, suppose the cluster has five nodes, located in three different regions, where the node master is cloud node.

$ kubectl get nodes -o wide

NAME         STATUS   ROLES    AGE   VERSION   INTERNAL-IP    
hhht-node1   Ready    <none>   20d   v1.16.2   10.48.115.9    
hhht-node2   Ready    <none>   20d   v1.16.2   10.48.115.10
master       Ready    master   20d   v1.16.2   10.48.115.8
wlcb-node1   Ready    <none>   20d   v1.16.2   10.48.115.11
wlcb-node2   Ready    <none>   20d   v1.16.2   10.48.115.12

We use a Gateway CR to manage nodes in different physical regions, and label nodes to indicate which Gateway these nodes are managed by.

For example, We label nodes in region cn-huhehaote with value gw-hhht, indicating that these nodes are managed by the gw-hhht gateway.

$ kubectl label nodes hhht-node1 hhht-node2 raven.openyurt.io/gateway=gw-hhht
hhht-node1 labeled
hhht-node2 labeled

Similarly, we label node in cloud with value gw-cloud, and nodes in region cn-wulanchabu with value gw-wlcb.

$ kubectl label nodes master raven.openyurt.io/gateway=gw-cloud
master labeled
$ kubectl label nodes wlcb-node1 wlcb-node2 raven.openyurt.io/gateway=gw-wlcb
wlcb-node1 labeled
wlcb-node2 labeled

install raven agent​

git clone https://github.com/openyurtio/raven.git
cd raven
make deploy

Wait for the raven agent daemon to be created successfully

$ kubectl get pod -n kube-system | grep raven-agent-ds
raven-agent-ds-2jw47                           1/1     Running   0          91s
raven-agent-ds-bq8zc                           1/1     Running   0          91s
raven-agent-ds-cj7k4                           1/1     Running   0          91s
raven-agent-ds-p9fk9                           1/1     Running   0          91s
raven-agent-ds-rlb9q                           1/1     Running   0          91s

How to Use​

Gateways​

  • create gateways
$ cat <<EOF | kubectl apply -f -
apiVersion: raven.openyurt.io/v1alpha1
kind: Gateway
metadata:
  name: gw-hhht
spec:
  endpoints:
    - nodeName: hhht-node1
      underNAT: true
    - nodeName: hhht-node2
      underNAT: true
      
---
apiVersion: raven.openyurt.io/v1alpha1
kind: Gateway
metadata:
  name: gw-cloud
spec:
  endpoints:
    - nodeName: master
      underNAT: false
      
---
apiVersion: raven.openyurt.io/v1alpha1
kind: Gateway
metadata:
  name: gw-wlcb
spec:
  endpoints:
    - nodeName: wlcb-node1
      underNAT: true
    - nodeName: wlcb-node2
      underNAT: true

EOF
  • Get gateways
$ kubectl get gateways

NAME      ACTIVEENDPOINT
gw-hhht   hhht-node1
gw-master master
gw-wlcb   wlcb-node1

Test pod-to-pod networking​

  • Create test pod
$ cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: Pod
metadata:
  name: fedora-1
spec:
  nodeName: hhht-node2
  containers:
    - name: fedora
      image: njucjc/fedora:latest
      imagePullPolicy: Always

---

apiVersion: v1
kind: Pod
metadata:
  name: fedora-2
spec:
  nodeName: wlcb-node2
  containers:
    - name: fedora
      image: njucjc/fedora:latest
      imagePullPolicy: Always


EOF
  • Get test pod
$ kubectl get pod -o wide
NAME       READY   STATUS    RESTARTS   AGE     IP            NODE                  NOMINATED NODE   READINESS GATES
fedora-1   1/1     Running   0          46s     10.14.10.67   hhht-node2            <none>           <none>
fedora-2   1/1     Running   0          46s     10.14.2.70    wlcb-node2            <none>           <none>

  • Test networking across edge
$ kubectl exec -it fedora-1 -- bash
[root@fedora-1]# ping 10.14.2.70 -c 4
PING 10.14.2.70 (10.14.2.70) 56(84) bytes of data.
64 bytes from 10.14.2.70: icmp_seq=1 ttl=60 time=32.2 ms
64 bytes from 10.14.2.70: icmp_seq=2 ttl=60 time=32.2 ms
64 bytes from 10.14.2.70: icmp_seq=3 ttl=60 time=32.0 ms
64 bytes from 10.14.2.70: icmp_seq=4 ttl=60 time=32.1 ms

--- 10.14.2.70 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3003ms
rtt min/avg/max/mdev = 32.047/32.136/32.246/0.081 ms