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Practice Test - Labels and Selectors

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Solutions to Practice Test - Labels and Selectors

1. We have deployed a number of PODs. They are labelled with tier, env and bu. How many PODs exist in the dev environment (env)?

   Here we are filtering pods by the value olf a label ``` kubectl get pods --selector env=dev ``` Count the pods (if any)
2. How many PODs are in the finance business unit (bu)?

   Similarly ... ``` kubectl get pods --selector bu=finance ``` Count the pods (if any)
3. How many objects are in the prod environment including PODs, ReplicaSets and any other objects?

   ``` kubectl get all --selector env=prod ``` Count everything (if anything)
4. Identify the POD which is part of the prod environment, the finance BU and of frontend tier?

   We can combine label expressions with comma. Only items with _all_ the given label/value pairs will be returned, i.e. it is an `and` condition. ``` kubectl get all --selector env=prod,bu=finance,tier=frontend ```
5. A ReplicaSet definition file is given replicaset-definition-1.yaml. Try to create the replicaset. There is an issue with the file. Try to fix it.

   ``` kubectl create -f replicaset-definition-1.yaml ``` Note the error message. Selector matchLabels should match with POD labels - Update `replicaset-definition-2.yaml` The values for labels on lines 9 and 13 should match. ``` $ kubectl create -f replicaset-definition-2.yaml ```