DSL Example

Kubes provides helper methods to make creating extra environments easy: with_extra. We’ll create extra environments under different namespaces.

Here’s how you achieve extra environments with the DSL form:

.kubes/resources/web/deployment.rb

name "demo-web"
labels(role: "web")
namespace with_extra("default")

replicas 1
image built_image # IE: user/demo-web:kubes-2020-06-13T19-55-16-43afc6e

.kubes/resources/web/service.rb

name "demo-web"
labels(role: "web")
namespace with_extra("default")

The name helper accounts for KUBES_EXTRA and appends the value.

Deployment

Then to create an additional environment, it’s simple:

kubectl create ns default-2
KUBES_EXTRA=2 kubes deploy

To check on the resources:

kubectl get all -n default-2

Using Different Name Instead

The example on this page uses the with_extra helper to create the deployment and service in another namespace. Another approach is to use the same namespace but different names based on KUBES_EXTRA. We also used the extra helper here, which is the KUBES_EXTRA value. Examples:

.kubes/resources/web/deployment.rb

name with_extra("demo-web")
labels(app: name, extra: extra)
namespace "default"

replicas 1
image built_image # IE: user/demo-web:kubes-2020-06-13T19-55-16-43afc6e

.kubes/resources/web/service.rb

name with_extra("demo-web")
labels(app: name, extra: extra)
namespace "default"

Adding label with the extra key is optional, but helps with filtering the resources.

kubectl get all -l extra=2
kubectl get all -l extra=3

Example:

$ kubectl get all -l extra=2
NAME                              READY   STATUS    RESTARTS   AGE
pod/demo-web-2-5f8b8cbcdc-dmbjj   1/1     Running   0          78s
pod/demo-web-2-5f8b8cbcdc-kg8hf   1/1     Running   0          78s

NAME                 TYPE       CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
service/demo-web-2   NodePort   172.16.158.166   <none>        80:30148/TCP   78s

NAME                         READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/demo-web-2   2/2     2            2           78s

NAME                                    DESIRED   CURRENT   READY   AGE
replicaset.apps/demo-web-2-5f8b8cbcdc   2         2         2       79s
$

The extra and with_extra helper methods provide flexibility to create these extra environments with either approach.