Merge branch 'fix-yaml-variables' into 'master'

Convert CI YAML variables keys into strings

So that this would be more consistent with the other variables,
which all of them are string based.

Closes #25554

See merge request !8088

2 files changed, 28 insertions, 1 deletions

diff --git a/lib/ci/gitlab_ci_yaml_processor.rb b/lib/ci/gitlab_ci_yaml_processor.rb
index fef652cb975..7463bd719d5 100644
--- a/lib/ci/gitlab_ci_yaml_processor.rb
+++ b/lib/ci/gitlab_ci_yaml_processor.rb
@@ -118,7 +118,7 @@ module Ci
         .merge(job_variables(name))
 
       variables.map do |key, value|
-        { key: key, value: value, public: true }
+        { key: key.to_s, value: value, public: true }
       end
     end
 
diff --git a/lib/gitlab/serialize/ci/variables.rb b/lib/gitlab/serialize/ci/variables.rb
new file mode 100644
index 00000000000..3a9443bfcd9
--- /dev/null
+++ b/lib/gitlab/serialize/ci/variables.rb
@@ -0,0 +1,27 @@
+module Gitlab
+  module Serialize
+    module Ci
+      # This serializer could make sure our YAML variables' keys and values
+      # are always strings. This is more for legacy build data because
+      # from now on we convert them into strings before saving to database.
+      module Variables
+        extend self
+
+        def load(string)
+          return unless string
+
+          object = YAML.safe_load(string, [Symbol])
+
+          object.map do |variable|
+            variable[:key] = variable[:key].to_s
+            variable
+          end
+        end
+
+        def dump(object)
+          YAML.dump(object)
+        end
+      end
+    end
+  end
+end