[Suggestion] Generate the YAML string where resources are separated with "---"

[cmoulliard]

Is your enhancement related to a problem? Please describe

Until now if we provide a List of objects to be serialized using the class io.quarkiverse.tekton.common.utils.Serialization and the method: asYaml() we got a wrong yaml result that we cannot install on a kubernetes cluster

---
- apiVersion: "v1"
  kind: "ConfigMap"
  metadata:
    name: "my-quarkus-hello-maven-settings"
  data:
...
- apiVersion: "v1"
  kind: "ConfigMap"
  metadata:
    name: "my-quarkus-hello-maven-settings"
  data:
...

Describe the solution you'd like

Ideally, the serializer should be able to iterate through the list of the objects to trim it and add a CR as such

    public void process(List<HasMetadata> resources) {
        // Iterate through the list of the resources to process them individually to include ---
        // as separator between them instead of a list of items
        StringBuilder yamlOutput = new StringBuilder();
        for (HasMetadata resource : resources) {
            String yaml = Serialization.asYaml(resource).trim();
            yamlOutput.append(yaml).append("\n");
        }

       write(yamlOutput.toString();

By doing that, we get as result

---
apiVersion: "v1"
kind: "ConfigMap"
metadata:
  name: "my-quarkus-hello-maven-settings"
data:
  settings.xml: |
...
---
apiVersion: "v1"
kind: "PersistentVolumeClaim"
metadata:
  name: "my-quarkus-hello-project-pvc"
spec:
  accessModes:
  - "ReadWriteOnce"
  resources:
    requests:
      storage: "2Gi"
  volumeMode: "Filesystem"
---
etc.

Describe alternatives you've considered

No response

Additional context

No response

[cmoulliard]

this is what I did in our util class

            /**
             * The array list of the kubernetes resources should be formated as such
             *
             * ---
             * manifest1
             * ---
             * manifest2
             * ...
             *
             * instead of a list as we got as error when deployed: cannot unmarshal array into Go value of type
             * unstructured.detector
             *
             * - manifest1
             * - manifest2
             * ...
             *
             */
            return ((List<HasMetadata>) object).stream()
                    .map(Serialization::writeValueAsYamlSafe)
                    .map(s -> s.replaceAll(TAG_PATTERN, BLANK))
                    .collect(Collectors.joining());

using

    private static YAMLFactory YAML_FACTORY = new YAMLFactory()
            .enable(YAMLGenerator.Feature.WRITE_DOC_START_MARKER)
            .disable(YAMLGenerator.Feature.SPLIT_LINES)
            .enable(YAMLGenerator.Feature.MINIMIZE_QUOTES)
            .enable(YAMLGenerator.Feature.ALWAYS_QUOTE_NUMBERS_AS_STRINGS);
...

    private static <T> String writeValueAsYamlSafe(T object) {
        try {
            return YAML_MAPPER.writeValueAsString(object);
        } catch (JsonProcessingException e) {
            throw new RuntimeException(e);
        }
    }