fix: Add automatic CSI registration path migration 23.1 -> 23.4 (#258)

# Description

Fixes #251

Author: sbernauer

CHANGELOG.md

@@ -12,9 +12,8 @@ All notable changes to this project will be documented in this file.
 ### Changed
 
 - Shortened the registration socket path for Microk8s compatibility ([#231]).
-  - After upgrading you will need to
-    `rmdir /var/lib/kubelet/plugins_registry/secrets.stackable.tech-reg.sock` manually.
-    This applies to *all* users, not just Microk8s.
+  - The old CSI registration path will be automatically migrated during upgrade ([#258]).
+  - You might need to manually remove `/var/lib/kubelet/plugins_registry/secrets.stackable.tech-reg.sock` when downgrading
 - Made kubeletDir configurable ([#232]).
   - Microk8s users will need to `--set kubeletDir=/var/snap/microk8s/common/var/lib/kubelet`.
 
@@ -23,6 +22,7 @@ All notable changes to this project will be documented in this file.
 [#232]: https://github.com/stackabletech/secret-operator/pull/232
 [#252]: https://github.com/stackabletech/secret-operator/pull/252
 [#257]: https://github.com/stackabletech/secret-operator/pull/257
+[#258]: https://github.com/stackabletech/secret-operator/pull/258
 
 ## [23.1.0] - 2023-01-23
 
@@ -75,7 +75,7 @@ All notable changes to this project will be documented in this file.
 
 - `autoTls` CA generation now requires opt-in ([#77]).
   - The default `tls` `SecretClass` now has this opt-in by default.
-  
+
 ### Removed
 
 - `k8sSearch` backend's option `secretLabels` has been removed ([#123]).

deploy/helm/secret-operator/templates/daemonset.yaml

@@ -74,6 +74,29 @@ spec:
               mountPath: /registration
             - name: csi
               mountPath: /csi
+      initContainers:
+        # https://github.com/stackabletech/secret-operator/issues/251
+        # In https://github.com/stackabletech/secret-operator/pull/231 we introduced a breaking change by shortening the CSI registration path
+        # This resulted in the following error "node_register.go:43] file exists in socketPath /registration/secrets.stackable.tech-reg.sock but it's not a socket.: &{name:secrets.stackable.tech-reg.sock size:4096 mode:2147484141 modTime:{wall:984732078ext:63815759330 loc:0xf864a0} sys:{Dev:64769 Ino:43688551 Nlink:2 Mode:16877 Uid:0 Gid:0 X__pad0:0 Rdev:0 Size:4096 Blksize:4096 Blocks:8 Atim:{Sec:1680162505 Nsec:36073186} Mtim:{Sec:1680162530 Nsec:984732078} Ctim:{Sec:1680162530 Nsec:984732078} X__unused:[0 0 0]}}"
+        # This init container removes the "old" directory, so that a unix socket with the same path can be created instead
+        # TODO: Should be removed in a release after 23.4
+        - name: migrate-longer-csi-registration-path
+          image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"
+          imagePullPolicy: {{ .Values.image.pullPolicy }}
+          command:
+            - /bin/bash
+            - -euo
+            - pipefail
+            - -x
+            - -c
+            - |
+              ls -la /registration
+              echo "Removing old (long) CSI registration path"
+              if [ -d "/registration/secrets.stackable.tech-reg.sock" ]; then rmdir /registration/secrets.stackable.tech-reg.sock; fi
+              ls -la /registration
+          volumeMounts:
+            - name: registration-sock
+              mountPath: /registration
       volumes:
         - name: registration-sock
           hostPath: