Local playground for testing and development §

Environment prerequisites §

Running project locally §

To spin-up a local environment using two k3s clusters and deploy a test application to both clusters, execute the command below:

make deploy-full-local-setup

Verify installation §

If local setup runs well, check if clusters are correctly installed

kubectl cluster-info --context k3d-test-gslb1 && kubectl cluster-info --context k3d-test-gslb2

Cluster test-gslb1 is exposing external DNS on default port :5053 while test-gslb2 on port :5054.

dig @localhost localtargets-roundrobin.cloud.example.com -p 5053 && dig -p 5054 @localhost localtargets-roundrobin.cloud.example.com

As expected result you should see eight A records divided between nodes of both clusters.

...
...
;; ANSWER SECTION:
localtargets-roundrobin.cloud.example.com. 30 IN A 172.16.0.3
localtargets-roundrobin.cloud.example.com. 30 IN A 172.16.0.2
...
...
localtargets-roundrobin.cloud.example.com. 30 IN A 172.16.0.5
localtargets-roundrobin.cloud.example.com. 30 IN A 172.16.0.4

Both clusters have podinfo installed on the top. Run following command and check if you get two json responses.

curl localhost:80 -H "Host:roundrobin.cloud.example.com" && curl localhost:81 -H "Host:roundrobin.cloud.example.com"

Run integration tests §

There is wide range of scenarios which GSLB provides and all of them are covered within tests. To check whether everything is running properly execute terratest :

make terratest

Cleaning §

Clean up your local development clusters with

make destroy-full-local-setup

Sample demo §

Round Robin §

Both clusters have podinfo installed on the top, where each cluster has been tagged to serve a different region. In this demo we will hit podinfo by wget -qO - roundrobin.cloud.example.com and depending on region will podinfo return us or eu. In current round robin implementation are IP addresses randomly picked. See Gslb manifest with round robin strategy

Run several times command below and watch message field.

make test-round-robin

As expected result you should see podinfo message changing

{
  "hostname": "frontend-podinfo-856bb46677-8p45m",
  ...
  "message": "us",
  ...
}
{
  "hostname": "frontend-podinfo-856bb46677-8p45m",
  ...
  "message": "eu",
  ...
}

Failover §

Both clusters have podinfo installed on the top where each cluster has been tagged to serve a different region. In this demo we will hit podinfo by wget -qO - failover.cloud.example.com and depending on whether podinfo is running inside the cluster it returns only eu or us. See Gslb manifest with failover strategy

Switch GLSB to failover mode:

make init-failover

Now both clusters are running in failover mode and podinfo is running on both of them. Run several times command below and watch message field.

make test-failover

You will see only eu podinfo is responsive:

{
  "hostname": "frontend-podinfo-856bb46677-8p45m",
  ...
  "message": "eu",
  ...
}

Stop podinfo on current (eu) cluster:

make stop-test-app

Several times hit application again

make test-failover

As expected result you should see only podinfo from second cluster (us) is responding:

{
  "hostname": "frontend-podinfo-856bb46677-v5nll",
  ...
  "message": "us",
  ...
}

It might happen that podinfo will be unavailable for a while due to DNS sync interval and default k8gb DNS TTL of 30 seconds

wget: server returned error: HTTP/1.1 503 Service Temporarily Unavailable

Start podinfo again on current (eu) cluster:

make start-test-app

and hit several times hit podinfo:

make test-failover

After DNS sync interval is over eu will be back

{
  "hostname": "frontend-podinfo-6945c9ddd7-xksrc",
  ...
  "message": "eu",
  ...
}

Optionally you can switch GLSB back to round-robin mode

make init-round-robin