fix: preserve string values in YAML encoding to prevent type conversion errors

.chloggen/fix_yaml-string-preservation.yaml

@@ -0,0 +1,19 @@
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. collector, target allocator, auto-instrumentation, opamp, github action)
+component: operator
+
+# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Fix string value preservation in YAML encoding to prevent automatic conversion of numeric-looking strings like \"0e12\" to float64"
+
+# One or more tracking issues related to the change
+issues: [4314]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: |
+  Removed the go_yaml.AutoInt() option from YAML encoder that was causing string values
+  containing scientific notation patterns to be automatically converted to numeric types,
+  which resulted in type validation errors during collector creation.

apis/v1beta1/config.go

@@ -390,7 +390,7 @@ func (c *Config) GetReadinessProbe(logger logr.Logger) (*corev1.Probe, error) {
 // Yaml encodes the current object and returns it as a string.
 func (c *Config) Yaml() (string, error) {
 	var buf bytes.Buffer
-	yamlEncoder := go_yaml.NewEncoder(&buf, go_yaml.IndentSequence(true), go_yaml.AutoInt())
+	yamlEncoder := go_yaml.NewEncoder(&buf, go_yaml.IndentSequence(true), go_yaml.UseSingleQuote(false))
 	if err := yamlEncoder.Encode(&c); err != nil {
 		return "", err
 	}

apis/v1beta1/config_test.go

@@ -195,6 +195,61 @@ service:
 	assert.Equal(t, expected, yamlCollector)
 }
 
+func TestConfigYamlStringPreservation(t *testing.T) {
+	// Test for issue https://github.com/open-telemetry/opentelemetry-operator/issues/4314
+	// Ensure that string values that look like numbers (e.g., "0e12") are preserved as strings
+	cfg := &Config{
+		Processors: &AnyConfig{
+			Object: map[string]interface{}{
+				"transform": map[string]interface{}{
+					"operations": []interface{}{
+						map[string]interface{}{
+							"new_value": "0e12", // This should remain a string, not be converted to float64
+						},
+					},
+				},
+			},
+		},
+		Receivers: AnyConfig{
+			Object: map[string]interface{}{
+				"otlp": map[string]interface{}{},
+			},
+		},
+		Exporters: AnyConfig{
+			Object: map[string]interface{}{
+				"debug": map[string]interface{}{},
+			},
+		},
+		Service: Service{
+			Pipelines: map[string]*Pipeline{
+				"traces": {
+					Receivers:  []string{"otlp"},
+					Processors: []string{"transform"},
+					Exporters:  []string{"debug"},
+				},
+			},
+		},
+	}
+
+	yamlOutput, err := cfg.Yaml()
+	require.NoError(t, err)
+
+	// Verify the string is not converted to a number by parsing back
+	var parsedConfig map[string]interface{}
+	err = go_yaml.Unmarshal([]byte(yamlOutput), &parsedConfig)
+	require.NoError(t, err)
+
+	processors := parsedConfig["processors"].(map[string]interface{})
+	transform := processors["transform"].(map[string]interface{})
+	operations := transform["operations"].([]interface{})
+	operation := operations[0].(map[string]interface{})
+	newValue := operation["new_value"]
+
+	// Ensure it's still a string, not a float64
+	assert.IsType(t, "", newValue)
+	assert.Equal(t, "0e12", newValue)
+}
+
 func TestGetTelemetryFromYAML(t *testing.T) {
 	collectorYaml, err := os.ReadFile("./testdata/otelcol-demo.yaml")
 	require.NoError(t, err)