Testing Network Connectivity¶
Once the environment is ready, we can test that network connectivity works among pods. First we check the status of the kubernetes cluster:
$ kubectl get nodes
NAME STATUS AGE VERSION
masterodl-vm Ready 1h v1.6.2
$ kubectl get pods
No resources found.
$ kubectl get svc
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes 10.0.0.129 <none> 443/TCP 1h
As we can see, this is a one node cluster with currently no pods running, and with the kubernetes API service listening on port 443 at 10.0.0.129 (which matches the ip assigned to the load balancer created for it).
To test proper configuration and connectivity we firstly create a sample deployment with:
$ kubectl run demo --image=celebdor/kuryr-demo
deployment "demo" created
After a few seconds, the container is up an running, and a neutron port was created with the same IP that got assigned to the pod:
$ kubectl get pods
NAME READY STATUS RESTARTS AGE
demo-2293951457-j29nb 1/1 Running 0 1m
$ kubectl describe pod demo-2293951457-j29nb | grep IP:
IP: 10.0.0.69
$ openstack port list | grep demo
| 73100cdb-84d6-4f33-93b2-e212966c65ac | demo-2293951457-j29nb | fa:16:3e:99:ac:ce | ip_address='10.0.0.69', subnet_id='3c3e18f9-d1d0-4674-b3be-9fc8561980d3' | ACTIVE |
We can then scale the deployment to 2 pods, and check connectivity between them:
$ kubectl scale deploy/demo --replicas=2
deployment "demo" scaled
$ kubectl get pods
NAME READY STATUS RESTARTS AGE
demo-2293951457-gdrv2 1/1 Running 0 9s
demo-2293951457-j29nb 1/1 Running 0 14m
$ openstack port list | grep demo
| 73100cdb-84d6-4f33-93b2-e212966c65ac | demo-2293951457-j29nb | fa:16:3e:99:ac:ce | ip_address='10.0.0.69', subnet_id='3c3e18f9-d1d0-4674-b3be-9fc8561980d3' | ACTIVE |
| 95e89edd-f513-4ec8-80d0-36839725e62d | demo-2293951457-gdrv2 | fa:16:3e:e6:b4:b9 | ip_address='10.0.0.75', subnet_id='3c3e18f9-d1d0-4674-b3be-9fc8561980d3' | ACTIVE |
$ kubectl exec -it demo-2293951457-j29nb -- /bin/sh
sh-4.2$ curl 10.0.0.69:8080
demo-2293951457-j29nb: HELLO, I AM ALIVE!!!
sh-4.2$ curl 10.0.0.75:8080
demo-2293951457-gdrv2: HELLO, I AM ALIVE!!!
sh-4.2$ ping 10.0.0.75
PING 10.0.0.75 (10.0.0.75) 56(84) bytes of data.
64 bytes from 10.0.0.75: icmp_seq=1 ttl=64 time=1.14 ms
64 bytes from 10.0.0.75: icmp_seq=2 ttl=64 time=0.250 ms
Next, we expose the service so that a neutron load balancer is created and the service is exposed and load balanced among the available pods:
$ kubectl get svc
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes 10.0.0.129 <none> 443/TCP 1h
$ kubectl expose deploy/demo --port=80 --target-port=8080
service "demo" exposed
$ kubectl get svc
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
demo 10.0.0.161 <none> 80/TCP 6s
kubernetes 10.0.0.129 <none> 443/TCP 1h
$ openstack loadbalancer list
+--------------------------------------+--------------------+----------------------------------+-------------+---------------------+----------+
| id | name | tenant_id | vip_address | provisioning_status | provider |
+--------------------------------------+--------------------+----------------------------------+-------------+---------------------+----------+
| 7d0cf5b5-b164-4b32-87d3-ae6c82513927 | default/kubernetes | 47c28e562795468ea52e92226e3bc7b1 | 10.0.0.129 | ACTIVE | haproxy |
| c34c8d0c-a683-497f-9530-a49021e4b502 | default/demo | 49e2683370f245e38ac2d6a8c16697b3 | 10.0.0.161 | ACTIVE | haproxy |
+--------------------------------------+--------------------+----------------------------------+-------------+---------------------+----------+
$ openstack loadbalancer listener list
+--------------------------------------+--------------------------------------+------------------------+----------------------------------+----------+---------------+----------------+
| id | default_pool_id | name | tenant_id | protocol | protocol_port | admin_state_up |
+--------------------------------------+--------------------------------------+------------------------+----------------------------------+----------+---------------+----------------+
| fc485508-c37a-48bd-9be3-898bbb7700fa | b12f00b9-44c0-430e-b1a1-e92b57247ad2 | default/demo:TCP:80 | 49e2683370f245e38ac2d6a8c16697b3 | TCP | 80 | True |
| abfbafd8-7609-4b7d-9def-4edddf2b887b | 70bed821-9a9f-4e1d-8c7e-7df89a923982 | default/kubernetes:443 | 47c28e562795468ea52e92226e3bc7b1 | HTTPS | 443 | True |
+--------------------------------------+--------------------------------------+------------------------+----------------------------------+----------+---------------+----------------+
$ openstack loadbalancer pool list
+--------------------------------------+------------------------+----------------------------------+--------------+----------+----------------+
| id | name | tenant_id | lb_algorithm | protocol | admin_state_up |
+--------------------------------------+------------------------+----------------------------------+--------------+----------+----------------+
| 70bed821-9a9f-4e1d-8c7e-7df89a923982 | default/kubernetes:443 | 47c28e562795468ea52e92226e3bc7b1 | ROUND_ROBIN | HTTPS | True |
| b12f00b9-44c0-430e-b1a1-e92b57247ad2 | default/demo:TCP:80 | 49e2683370f245e38ac2d6a8c16697b3 | ROUND_ROBIN | TCP | True |
+--------------------------------------+------------------------+----------------------------------+--------------+----------+----------------+
$ openstack loadbalancer member list default/demo:TCP:80
+--------------------------------------+------------------------------------+----------------------------------+-----------+---------------+--------+--------------------------------------+----------------+
| id | name | tenant_id | address | protocol_port | weight | subnet_id | admin_state_up |
+--------------------------------------+------------------------------------+----------------------------------+-----------+---------------+--------+--------------------------------------+----------------+
| c0057ce6-64da-4613-b284-faf5477533ab | default/demo-2293951457-j29nb:8080 | 49e2683370f245e38ac2d6a8c16697b3 | 10.0.0.69 | 8080 | 1 | 55405e9d-4e25-4a55-bac2-e25ee88584e1 | True |
| 7a0c0ef9-35ce-4134-b92a-2e73f0f8fe98 | default/demo-2293951457-gdrv2:8080 | 49e2683370f245e38ac2d6a8c16697b3 | 10.0.0.75 | 8080 | 1 | 55405e9d-4e25-4a55-bac2-e25ee88584e1 | True |
+--------------------------------------+------------------------------------+----------------------------------+-----------+---------------+--------+--------------------------------------+----------------+
We can see that both pods are included as members and that the demo cluster-ip matches with the loadbalancer vip_address. In order to check loadbalancing among them, we are going to curl the cluster-ip from one of the pods and see that each of the pods is replying at a time:
$ kubectl exec -it demo-2293951457-j29nb -- /bin/sh
sh-4.2$ curl 10.0.0.161
demo-2293951457-j29nb: HELLO, I AM ALIVE!!!
sh-4.2$ curl 10.0.0.161
demo-2293951457-gdrv2: HELLO, I AM ALIVE!!!
