Services provide stable endpoints for Pods based on a set of labels.
In this lab you will create the monolith
service and "expose" the secure-monolith
Pod externally. You will learn how to:
- Create a service
- Use label selectors to expose a limited set of Pods externally
Explore the monolith service configuration file:
cat services/monolith.yaml
Create the monolith service using kubectl:
kubectl create -f services/monolith.yaml
Beceause we can't reach the service externaly at the moment we start a curl container to run from.
kubectl create -f pods/curl.yaml
kubectl exec curl --stdin --tty -- sh
curl -v -k https://monolith
- Why are you unable to get a response from the
monolith
service?
kubectl get services monolith
kubectl describe services monolith
- How many endpoints does the
monolith
service have? - What labels must a Pod have to be picked up by the
monolith
service?
Currently the monolith
service does not have any endpoints. One way to troubleshoot an issue like this is to use the kubectl get pods
command with a label query.
kubectl get pods -l "app=monolith"
kubectl get pods -l "app=monolith,secure=enabled"
Notice this label query does not print any results
Use the kubectl label
command to add the missing secure=enabled
label to the secure-monolith
Pod.
kubectl label pods secure-monolith 'secure=enabled'
View the list of endpoints on the monolith
service:
kubectl describe services monolith
- How many endpoints does the
monolith
service have?
Curl above
In this exercise you will observe what happens when a required label is removed from a Pod.
Use the kubectl label
command to remove the secure
label from the secure-monolith
Pod.
kubectl label pods secure-monolith secure-
View the list of endpoints on the monolith
service:
kubectl describe services monolith
- How many endpoints does the
monolith
service have?
In this lab you learned how to expose Pods using services and labels.