feat(common): BREAKING CHANGE allow gitops cnpg recovery without editing values (#33786)

**Description**
Currently CNPG requires backup and recovery revision to be different
As CNPG errors out when you try to backup towards a target that was used
by an old instance of the cluster/app.

This patch adds an annotation that disables this check on the CNPG
level.
Which means CNPG-backed applications can be recovered and backed-up in a
gitops compatible way, just like volsync.

Just configure backup and restore to the same settings and let it rip.

If users want extra security, as this feature disables a security
precaution, users should think about enabling s3 snapshots as well.

**⚙️ Type of change**

- [x] ⚙️ Feature/App addition
- [ ] 🪛 Bugfix
- [x] ⚠️ Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [x] 🔃 Refactor of current code
- [ ] 📜 Documentation Changes

**🧪 How Has This Been Tested?**
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Please describe the tests that you ran to verify your changes. Provide
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**📃 Notes:**
It also moves around the pgVersion fallbackDefault, which is technically
a breaking change

**✔️ Checklist:**

- [ ] ⚖️ My code follows the style guidelines of this project
- [ ] 👀 I have performed a self-review of my own code
- [ ] #️⃣ I have commented my code, particularly in hard-to-understand
areas
- [ ] 📄 I have made changes to the documentation
- [ ] 🧪 I have added tests to this description that prove my fix is
effective or that my feature works
- [ ] ⬆️ I increased versions for any altered app according to semantic
versioning
- [ ] I made sure the title starts with `feat(chart-name):`,
`fix(chart-name):`, `chore(chart-name):`, `docs(chart-name):` or
`fix(docs):`

**➕ App addition**

If this PR is an app addition please make sure you have done the
following.

- [ ] 🖼️ I have added an icon in the Chart's root directory called
`icon.png`

---

_Please don't blindly check all the boxes. Read them and only check
those that apply.
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---------

Signed-off-by: Kjeld Schouten <info@kjeldschouten.nl>

charts/library/common-test/tests/cnpg/cluster_spec_test.yaml

@@ -147,7 +147,8 @@ tests:
         tag: "15.6"
       global:
         fallbackDefaults:
-          pgVersion: 15
+          cnpg:
+            pgVersion: 15
           vctAccessModes:
             - ReadWriteMany
             - ReadWriteOnce

charts/library/common/templates/class/cnpg/_cluster.tpl

@@ -24,6 +24,7 @@
   {{- $logLevel := "info" -}}
   {{- $accessModes := $rootCtx.Values.global.fallbackDefaults.vctAccessModes -}}
   {{- $walAccessModes := $rootCtx.Values.global.fallbackDefaults.vctAccessModes -}}
+  {{- $skipEmptyWalArchiveCheck := $rootCtx.Values.global.fallbackDefaults.cnpg.skipEmptyWalArchiveCheck -}}
 
   {{/* Make sure keys exist before try to access any sub keys */}}
   {{- if not (hasKey $objectData "cluster") -}}
@@ -140,6 +141,10 @@
     {{- $walAccessModes = . -}}
   {{- end -}}
 
+  {{- with $objectData.cluster.skipEmptyWalArchiveCheck -}}
+    {{- $skipEmptyWalArchiveCheck = . -}}
+  {{- end -}}
+
   {{- $imageName := $objectData.cluster.imageName -}}
   {{- if not $imageName -}}
     {{/* Ensure version and container tracking */}}
@@ -171,6 +176,7 @@ metadata:
   annotations:
     cnpg.io/hibernation: {{ $hibernation | quote }}
     checksum/secrets: {{ toJson $rootCtx.Values.secret | sha256sum }}
+    cnpg.io/skipEmptyWalArchiveCheck: $skipEmptyWalArchiveCheck
   {{- $annotations := (mustMerge $clusterAnnotations (include "tc.v1.common.lib.metadata.allAnnotations" $rootCtx | fromYaml)) -}}
   {{- with (include "tc.v1.common.lib.metadata.render" (dict "rootCtx" $rootCtx "annotations" $annotations) | trim) }}
     {{- . | nindent 4 }}

charts/library/common/templates/spawner/_cnpg.tpl

@@ -24,7 +24,7 @@
     {{- if eq $enabled "true" -}}
 
       {{/* Handle version string */}}
-      {{- $pgVersion := ($objectData.pgVersion | default $.Values.global.fallbackDefaults.pgVersion) | toString -}}
+      {{- $pgVersion := ($objectData.pgVersion | default $.Values.global.fallbackDefaults.cnpg.pgVersion) | toString -}}
 
       {{/* Set the updated pgVersion version to objectData */}}
       {{- $_ := set $objectData "pgVersion" $pgVersion -}}

charts/library/common/values.yaml

@@ -56,10 +56,13 @@ global:
     # -- Define a postgresql version for CNPG
     # will be used for all CNPG objects
     # Can be overruled per CNPG objects
-    pgVersion: 16
+
     # -- Define a topologyKey for default topologySpreadConstraints
     # Will be used when defaultSpread: true
     topologyKey: kubernetes.io/hostname
+    cnpg:
+      pgVersion: 16
+      skipEmptyWalArchiveCheck: true
   metallb:
     # -- Adds metalLB annotations to services
     addServiceAnnotations: true
@@ -1051,6 +1054,9 @@ cnpg:
 
       # set to true on single-node clusters to allow PVCs to be kept on instance restart
       singleNode: false
+
+      ## set to configure the skipEmptyWalArchiveCheck annotation
+      # skipEmptyWalArchiveCheck: true
       # # -- storage size for the data pvc's
       # # Follows the same spec as .Values.Persistence type=PVC
       # storage: