cli-utils/examples/alphaTestExamples/pruneAndDelete.md

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[kind]: https://github.com/kubernetes-sigs/kind
# Demo: Lifecycle directives
This demo shows how it is possible to use a lifecycle directive to
change the behavior of prune and delete for specific resources.
First define a place to work:
<!-- @makeWorkplace @testE2EAgainstLatestRelease -->
```
DEMO_HOME=$(mktemp -d)
```
Alternatively, use
> ```
> DEMO_HOME=~/hello
> ```
## Establish the base
<!-- @createBase @testE2EAgainstLatestRelease -->
```
BASE=$DEMO_HOME/base
mkdir -p $BASE
OUTPUT=$DEMO_HOME/output
mkdir -p $OUTPUT
function expectedOutputLine() {
test 1 == \
$(grep "$@" $OUTPUT/status | wc -l); \
echo $?
}
```
In this example we will just use two ConfigMap resources for simplicity, but
of course any type of resource can be used. On one of our ConfigMaps, we add the
**cli-utils.sigs.k8s.io/on-remove** annotation with the value of **keep**. This
annotation tells the kapply tool that this resource should not be deleted, even
if it would otherwise be pruned or deleted with the destroy command.
<!-- @createFirstCM @testE2EAgainstLatestRelease-->
```
cat <<EOF >$BASE/configMap1.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: firstmap
data:
artist: Ornette Coleman
album: The shape of jazz to come
EOF
```
This ConfigMap includes the lifecycle directive annotation
<!-- @createSecondCM @testE2EAgainstLatestRelease-->
```
cat <<EOF >$BASE/configMap2.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: secondmap
annotations:
cli-utils.sigs.k8s.io/on-remove: keep
data:
artist: Husker Du
album: New Day Rising
EOF
```
## Run end-to-end tests
The following requires installation of [kind].
Delete any existing kind cluster and create a new one. By default the name of the cluster is "kind"
<!-- @deleteAndCreateKindCluster @testE2EAgainstLatestRelease -->
```
kind delete cluster
kind create cluster
```
Use the kapply init command to generate the inventory template. This contains
the namespace and inventory id used by apply to create inventory objects.
<!-- @createInventoryTemplate @testE2EAgainstLatestRelease-->
```
kapply init $BASE > $OUTPUT/status
expectedOutputLine "namespace: default is used for inventory object"
```
Apply both resources to the cluster.
<!-- @runApply @testE2EAgainstLatestRelease -->
```
kapply apply $BASE --reconcile-timeout=1m > $OUTPUT/status
```
Use the preview command to show what will happen if we run destroy. This should
show that the second ConfigMap will not be deleted even when using the destroy
command.
<!-- @runDestroyPreview @testE2EAgainstLatestRelease -->
```
kapply preview --destroy $BASE > $OUTPUT/status
expectedOutputLine "configmap/firstmap deleted (preview)"
expectedOutputLine "configmap/secondmap delete skipped (preview)"
```
We run the destroy command and see that the resource without the annotation
has been deleted, while the resource with the annotation is still in the
cluster.
<!-- @runDestroy @testE2EAgainstLatestRelease -->
```
kapply destroy $BASE > $OUTPUT/status
expectedOutputLine "configmap/firstmap deleted"
expectedOutputLine "configmap/secondmap delete skipped"
kubectl get cm --no-headers | awk '{print $1}' > $OUTPUT/status
expectedOutputLine "secondmap"
```
Apply the resources back to the cluster so we can demonstrate the lifecycle
directive with pruning.
<!-- @runApplyAgain @testE2EAgainstLatestRelease -->
```
kapply apply $BASE --reconcile-timeout=1m > $OUTPUT/status
```
Delete the manifest for the second configmap
<!-- @runDeleteManifest @testE2EAgainstLatestRelease -->
```
rm $BASE/configMap2.yaml
```
Run preview to see that while secondmap would normally be pruned, it
will instead be skipped due to the lifecycle directive.
<!-- @runPreviewForPrune @testE2EAgainstLatestRelease -->
```
kapply preview $BASE > $OUTPUT/status
expectedOutputLine "configmap/secondmap prune skipped (preview)"
```
Run apply and verify that secondmap is still in the cluster.
<!-- @runApplyToPrune @testE2EAgainstLatestRelease -->
```
kapply apply $BASE > $OUTPUT/status
expectedOutputLine "configmap/secondmap prune skipped"
kubectl get cm --no-headers | awk '{print $1}' > $OUTPUT/status
expectedOutputLine "secondmap"
```