ced4568andClaude Sonnet 5
dbcc210889
root-07-m03-services-and-service-discovery — a new, full gold-standard- pattern module: the Service/Endpoints/DNS request path, choosing the right Service type. Lesson, demonstration (a Service with zero Endpoints — the single fastest diagnostic check for this failure class), knowledge check, guided exercise (ClusterIP vs. NodePort vs. LoadBalancer for three real components), a real Lab (expose-service-basics), and a reflection. root-07-m04-ingress-networkpolicy-foundations — a new PARTIAL module: Ingress and NetworkPolicy at the architectural level (the security- control framing of NetworkPolicy is deliberately deferred to ROOT 09). Lesson + knowledge check + real Labs (ingress-task, network-policy). Co-Authored-By: Claude Sonnet 5 <[email protected]>
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Launch Lab: Exposing an Application
Time to create a real Service in your disposable Lab and connect it to a real Deployment.
What you're doing
A redis Deployment is running, but other Pods can't reliably reach it because Pod IPs change
whenever a Pod restarts — exactly the problem the lesson opened with. Your task is to create a
stable ClusterIP Service in front of it.
Before you start
Recall the request path from the lesson: your Service's selector has to match the Deployment
Pods' actual labels, or you'll end up with the empty-Endpoints situation from the
demonstration. Check the Deployment's Pod labels before writing your Service's selector, don't
guess at them.
Your task in this Lab
Create a ClusterIP Service exposing the redis Deployment on the correct port. Once it's
created, verify it the same way the demonstration did: kubectl get service, then kubectl get endpoints to confirm it actually has a non-empty Endpoints list, not just that the Service
object exists.
This Lab has its own in-context hints if you get stuck.
When you're done, return to this module for a reflection on why service discovery is infrastructure, not magic.
Instructor Notes
Classroom flow: Encourage students to run kubectl get endpoints as their OWN verification
step even though the Lab's automated validation will check this too — building the habit of
checking Endpoints, not just "the Service exists," is the actual transferable skill here.
Approximate timing: 10-15 minutes.
Common mistake to watch for: a selector that matches on the wrong label key/value, or a
port/targetPort mismatch (the Service's port is what clients connect to; targetPort is what
the container actually listens on — conflating the two is a very common first-time error).