Merge pull request #39308 from sftim/20230306_pod_qos_tweaks

Tweak docs about QoS classes

Author: k8s-ci-robot

content/en/docs/concepts/workloads/pods/pod-qos.md

@@ -1,7 +1,7 @@
 ---
 title: Pod Quality of Service Classes
 content_type: concept
-weight: 30
+weight: 85
 ---
 
 <!-- overview -->

content/en/docs/reference/glossary/qos-class.md

@@ -2,7 +2,7 @@
 title: QoS Class
 id: qos-class
 date: 2019-04-15
-full_link: /docs/concepts/workloads/pods/pod-quality/
+full_link: /docs/concepts/workloads/pods/pod-qos/
 short_description: >
   QoS Class (Quality of Service Class) provides a way for Kubernetes to classify pods within the cluster into several classes and make decisions about scheduling and eviction.
 

content/en/docs/tasks/configure-pod-container/quality-service-pod.md

@@ -8,28 +8,28 @@ weight: 30
 <!-- overview -->
 
 This page shows how to configure Pods so that they will be assigned particular
-Quality of Service (QoS) classes. Kubernetes uses QoS classes to make decisions about evicting Pods when Node resources are exceeded.
+{{< glossary_tooltip text="Quality of Service (QoS) classes" term_id="qos-class" >}}.
+Kubernetes uses QoS classes to make decisions about evicting Pods when Node resources are exceeded.
 
 
+When Kubernetes creates a Pod it assigns one of these QoS classes to the Pod:
+
+* [Guaranteed](/docs/concepts/workloads/pods/pod-qos/#guaranteed)
+* [Burstable](/docs/concepts/workloads/pods/pod-qos/#burstable)
+* [BestEffort](/docs/concepts/workloads/pods/pod-qos/#besteffort)
 
 
 ## {{% heading "prerequisites" %}}
 
 
-{{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
+{{< include "task-tutorial-prereqs.md" >}}
 
+You also need to be able to create and delete namespaces.
 
 
 
 <!-- steps -->
 
-## QoS classes
-
-When Kubernetes creates a Pod it assigns one of these QoS classes to the Pod:
-
-* Guaranteed
-* Burstable
-* BestEffort
 
 ## Create a namespace
 
@@ -42,7 +42,7 @@ kubectl create namespace qos-example
 
 ## Create a Pod that gets assigned a QoS class of Guaranteed
 
-For a Pod to be given a QoS class of Guaranteed:
+For a Pod to be given a QoS class of `Guaranteed`:
 
 * Every Container in the Pod must have a memory limit and a memory request.
 * For every Container in the Pod, the memory limit must equal the memory request.
@@ -53,7 +53,7 @@ These restrictions apply to init containers and app containers equally.
 [Ephemeral containers](/docs/concepts/workloads/pods/ephemeral-containers/)
 cannot define resources so these restrictions do not apply.
 
-Here is the configuration file for a Pod that has one Container. The Container has a memory limit and a
+Here is a manifest for a Pod that has one Container. The Container has a memory limit and a
 memory request, both equal to 200 MiB. The Container has a CPU limit and a CPU request, both equal to 700 milliCPU:
 
 {{< codenew file="pods/qos/qos-pod.yaml" >}}
@@ -70,7 +70,7 @@ View detailed information about the Pod:
 kubectl get pod qos-demo --namespace=qos-example --output=yaml
 ```
 
-The output shows that Kubernetes gave the Pod a QoS class of Guaranteed. The output also
+The output shows that Kubernetes gave the Pod a QoS class of `Guaranteed`. The output also
 verifies that the Pod Container has a memory request that matches its memory limit, and it has
 a CPU request that matches its CPU limit.
 
@@ -97,6 +97,9 @@ CPU limit, but does not specify a CPU request, Kubernetes automatically assigns
 the limit.
 {{< /note >}}
 
+<!-- 4th level heading to suppress entry in nav -->
+#### Clean up {#clean-up-guaranteed}
+
 Delete your Pod:
 
 ```shell
@@ -105,12 +108,12 @@ kubectl delete pod qos-demo --namespace=qos-example
 
 ## Create a Pod that gets assigned a QoS class of Burstable
 
-A Pod is given a QoS class of Burstable if:
+A Pod is given a QoS class of `Burstable` if:
 
-* The Pod does not meet the criteria for QoS class Guaranteed.
+* The Pod does not meet the criteria for QoS class `Guaranteed`.
 * At least one Container in the Pod has a memory or CPU request or limit.
 
-Here is the configuration file for a Pod that has one Container. The Container has a memory limit of 200 MiB
+Here is a manifest for a Pod that has one Container. The Container has a memory limit of 200 MiB
 and a memory request of 100 MiB.
 
 {{< codenew file="pods/qos/qos-pod-2.yaml" >}}
@@ -127,7 +130,7 @@ View detailed information about the Pod:
 kubectl get pod qos-demo-2 --namespace=qos-example --output=yaml
 ```
 
-The output shows that Kubernetes gave the Pod a QoS class of Burstable.
+The output shows that Kubernetes gave the Pod a QoS class of `Burstable`:
 
 ```yaml
 spec:
@@ -145,6 +148,9 @@ status:
   qosClass: Burstable
 ```
 
+<!-- 4th level heading to suppress entry in nav -->
+#### Clean up {#clean-up-burstable}
+
 Delete your Pod:
 
 ```shell
@@ -153,10 +159,10 @@ kubectl delete pod qos-demo-2 --namespace=qos-example
 
 ## Create a Pod that gets assigned a QoS class of BestEffort
 
-For a Pod to be given a QoS class of BestEffort, the Containers in the Pod must not
+For a Pod to be given a QoS class of `BestEffort`, the Containers in the Pod must not
 have any memory or CPU limits or requests.
 
-Here is the configuration file for a Pod that has one Container. The Container has no memory or CPU
+Here is a manifest for a Pod that has one Container. The Container has no memory or CPU
 limits or requests:
 
 {{< codenew file="pods/qos/qos-pod-3.yaml" >}}
@@ -173,7 +179,7 @@ View detailed information about the Pod:
 kubectl get pod qos-demo-3 --namespace=qos-example --output=yaml
 ```
 
-The output shows that Kubernetes gave the Pod a QoS class of BestEffort.
+The output shows that Kubernetes gave the Pod a QoS class of `BestEffort`:
 
 ```yaml
 spec:
@@ -185,6 +191,9 @@ status:
   qosClass: BestEffort
 ```
 
+<!-- 4th level heading to suppress entry in nav -->
+#### Clean up {#clean-up-besteffort}
+
 Delete your Pod:
 
 ```shell
@@ -193,13 +202,13 @@ kubectl delete pod qos-demo-3 --namespace=qos-example
 
 ## Create a Pod that has two Containers
 
-Here is the configuration file for a Pod that has two Containers. One container specifies a memory
+Here is a manifest for a Pod that has two Containers. One container specifies a memory
 request of 200 MiB. The other Container does not specify any requests or limits.
 
 {{< codenew file="pods/qos/qos-pod-4.yaml" >}}
 
-Notice that this Pod meets the criteria for QoS class Burstable. That is, it does not meet the
-criteria for QoS class Guaranteed, and one of its Containers has a memory request.
+Notice that this Pod meets the criteria for QoS class `Burstable`. That is, it does not meet the
+criteria for QoS class `Guaranteed`, and one of its Containers has a memory request.
 
 Create the Pod:
 
@@ -213,7 +222,7 @@ View detailed information about the Pod:
 kubectl get pod qos-demo-4 --namespace=qos-example --output=yaml
 ```
 
-The output shows that Kubernetes gave the Pod a QoS class of Burstable:
+The output shows that Kubernetes gave the Pod a QoS class of `Burstable`:
 
 ```yaml
 spec:
@@ -231,12 +240,19 @@ status:
   qosClass: Burstable
 ```
 
-Delete your Pod:
+## Retrieve the QoS class for a Pod
 
-```shell
-kubectl delete pod qos-demo-4 --namespace=qos-example
+Rather than see all the fields, you can view just the field you need:
+
+```bash
+kubectl --namespace=qos-example get pod qos-demo-4 -o jsonpath='{ .status.qosClass}{"\n"}'
 ```
 
+```none
+Burstable
+```
+
+
 ## Clean up
 
 Delete your namespace: