Allow knative do be uninstalled:

- After uninstalling the knative helm chart it's necessary to also
remove some leftover resources to allow the cluster to be clean
and knative to be reinstalleable.
- Adds knative uninstall disclaimer
- Uninstall ksvc before uninstalling knative

Make list of Knative and Ingres resources explicit

- To avoid deleting unwanted resources we are listing exact
which resources will be deleted rather than simply deleting any
resource that contains istio or knative words.

2 files changed, 9 insertions, 12 deletions

diff --git a/lib/gitlab/kubernetes/helm/delete_command.rb b/lib/gitlab/kubernetes/helm/delete_command.rb
index 876994d2678..aeba4a54b6d 100644
--- a/lib/gitlab/kubernetes/helm/delete_command.rb
+++ b/lib/gitlab/kubernetes/helm/delete_command.rb
@@ -7,19 +7,24 @@ module Gitlab
         include BaseCommand
         include ClientCommand
 
+        attr_reader :predelete, :postdelete
         attr_accessor :name, :files
 
-        def initialize(name:, rbac:, files:)
+        def initialize(name:, rbac:, files:, predelete: nil, postdelete: nil)
           @name = name
           @files = files
           @rbac = rbac
+          @predelete = predelete
+          @postdelete = postdelete
         end
 
         def generate_script
           super + [
             init_command,
             wait_for_tiller_command,
-            delete_command
+            predelete,
+            delete_command,
+            postdelete
           ].compact.join("\n")
         end
 
diff --git a/lib/gitlab/kubernetes/helm/install_command.rb b/lib/gitlab/kubernetes/helm/install_command.rb
index 9744a5f3d8a..f572bc43533 100644
--- a/lib/gitlab/kubernetes/helm/install_command.rb
+++ b/lib/gitlab/kubernetes/helm/install_command.rb
@@ -27,9 +27,9 @@ module Gitlab
             wait_for_tiller_command,
             repository_command,
             repository_update_command,
-            preinstall_command,
+            preinstall,
             install_command,
-            postinstall_command
+            postinstall
           ].compact.join("\n")
         end
 
@@ -58,14 +58,6 @@ module Gitlab
           command.shelljoin
         end
 
-        def preinstall_command
-          preinstall.join("\n") if preinstall
-        end
-
-        def postinstall_command
-          postinstall.join("\n") if postinstall
-        end
-
         def install_flag
           ['--install']
         end