Improve YAML parsing to handle list sequences within SLI spec

internal/convert/convert.go

@@ -1005,7 +1005,9 @@ func printYaml(out io.Writer, object interface{}) error {
  return fmt.Errorf("issue marshaling content: %w", err)
  }
 
- fmt.Fprint(out, "---\n")
+ if _, err = fmt.Fprint(out, "---\n"); err != nil {
+ return err
+ }
  _, err = out.Write(yml)
  if err != nil {
  return fmt.Errorf("issue writing content: %w", err)

pkg/manifest/v1/indicator.go

@@ -70,15 +70,15 @@ type MetricSource struct {
  MetricSourceSpec map[string]string `yaml:"spec" validate:"required_without=MetricSourceRef"`
 }
 
-// UnmarshalYAML is used to override the default unmarshal behavior
-// Since MetricSources don't have a determined structure, we need to do a few things here:
-// 1. Pull out the MetricSourceRef and Type separately, and add them to the MetricSource
-// 2. Attempt to unmarshal the MetricSourceSpec, which can be either a string or an array.
-// 2a. If its a string, add it as a single string
-// 2b. If its an array, flatten it to a single string
+// UnmarshalYAML is used to override the default unmarshal behavior.
+// MetricSources can have varying structures, so this method performs the following tasks:
+// 1. Extracts the MetricSourceRef and Type separately, and assigns them to the MetricSource.
+// 2. Attempts to unmarshal the MetricSourceSpec, which can be either a string, a list, or a more complex structure:
+// 2a. If it's a scalar string, it is added directly as a single string.
+// 2b. If it's a list of scalar values, they are concatenated into a single semicolon separated string.
+// 2c. If it's a more complex sequence, the values are processed and flattened appropriately.
 //
 // This also assumes a certain flat structure that we can revisit if the need arises.
-//
 
 func (m *MetricSource) UnmarshalYAML(value *yaml.Node) error {
  // temp struct to unmarshal the string values
@@ -108,7 +108,9 @@ func (m *MetricSource) UnmarshalYAML(value *yaml.Node) error {
  // top level string that we will join with a semicolon
  seqStrings := []string{}
  for _, node := range v.Content {
- if node.Kind == yaml.MappingNode {
+ if node.Kind == yaml.ScalarNode {
+ seqStrings = append(seqStrings, node.Value)
+ } else if node.Kind == yaml.MappingNode {
  // each of these are k/v pairs that we will join with a comma
  kvPairs := []string{}
  for i := 0; i < len(node.Content); i += 2 {

pkg/manifest/v1/indicator_test.go

@@ -81,6 +81,24 @@ spec:
  },
  },
  },
+ {
+ name: "Prometheus - Two labels",
+ yaml: `metricSourceRef: thanos
+type: Prometheus
+spec:
+ query: http_requests_total{}
+ dimensions:
+ - following
+ - another`,
+ want: MetricSource{
+ MetricSourceRef: "thanos",
+ Type: "Prometheus",
+ MetricSourceSpec: map[string]string{
+ "query": "http_requests_total{}",
+ "dimensions": "following;another",
+ },
+ },
+ },
  }
 
  for _, tt := range tests {