Make Helm chart cleanup job container image configurable

We `parameters.backup_k8up.images.kubectl` and add a postprocessing
filter which patches the cleanup job to use the image location specified
in that image parameter.

class/backup-k8up.yml

@@ -39,3 +39,6 @@ parameters:
         - type: jsonnet
           filter: postprocess/optional_global_config.jsonnet
           path: ${_instance}/01_k8up_helmchart/k8up/templates
+        - type: jsonnet
+          filter: postprocess/cleanup-job.jsonnet
+          path: ${_instance}/01_k8up_helmchart/k8up/templates

class/defaults.yml

@@ -11,6 +11,10 @@ parameters:
         repository: k8up-io/k8up
         tag: v2.7.1
         pullPolicy: IfNotPresent
+      kubectl:
+        registry: docker.io
+        repository: bitnami/kubectl
+        tag: latest
 
     helmReleaseName: k8up
 

postprocess/cleanup-job.jsonnet

@@ -0,0 +1,28 @@
+local com = import 'lib/commodore.libjsonnet';
+local kube = import 'lib/kube.libjsonnet';
+
+local inv = com.inventory();
+local params = inv.parameters.backup_k8up;
+
+local chart_output_dir = std.extVar('output_path');
+
+local patch_registry(obj) =
+  if obj.kind == 'Job' then
+    obj {
+      spec+: {
+        template+: {
+          spec+: {
+            containers: [
+              c {
+                image: '%(registry)s/%(repository)s:%(tag)s' % params.images.kubectl,
+              }
+              for c in super.containers
+            ],
+          },
+        },
+      },
+    }
+  else
+    obj;
+
+com.fixupDir(chart_output_dir, patch_registry)

tests/golden/defaults/backup-k8up/backup-k8up/01_k8up_helmchart/k8up/templates/cleanup-hook.yaml

@@ -100,7 +100,7 @@ spec:
           command:
             - sh
             - -c
-          image: bitnami/kubectl:latest
+          image: docker.io/bitnami/kubectl:latest
           name: k8up-cleanup
       restartPolicy: Never
       serviceAccountName: cleanup-service-account