[cmd/mdatagen] Implement numeric validation in generated Go config code (#14806) (#15270)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->

Implements support for the JSON Schema numeric validation keywords
'minimum', 'maximum', 'exclusiveMaximum' and 'exclusiveMinimum' in
mdatagen config generation pipeline.

<!-- Issue number if applicable -->
Fixes #14806

<!--Describe what testing was performed and which tests were added.-->

* Added unit tests in generation_test.go
* The samplescraper golden file (`generated_config.go`) is updated to
reflect the new generated output.

Author: blami

.chloggen/mdatagen_numeric_validators.yaml

@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. receiver/otlp)
+component: cmd/mdatagen
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Handle numeric validators in generated config structs
+
+# One or more tracking issues or pull requests related to the change
+issues: [14806]
+
+# (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: Supported validators include `minimum`, `maximum`, `exclusiveMinimum` and `exclusiveMaximum`.
+
+# Optional: The change log or logs in which this entry should be included
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users
+# Include 'api' if there is a change to a library API
+# Default: '[user]'
+change_logs: [api]

cmd/mdatagen/internal/cfggen/generation.go

@@ -441,14 +441,19 @@ func ExtractValidators(md *ConfigMetadata) []Validator {
 }
 
 type ValidationRules struct {
-	MaxLength *int
-	MinLength *int
-	Pattern   *string
-	Required  bool
+	MaxLength        *int
+	MinLength        *int
+	Pattern          *string
+	Required         bool
+	Minimum          *float64
+	Maximum          *float64
+	ExclusiveMinimum *float64
+	ExclusiveMaximum *float64
 }
 
 func (vr *ValidationRules) HasValueRule() bool {
-	return vr.MaxLength != nil || vr.MinLength != nil || vr.Pattern != nil
+	return vr.MaxLength != nil || vr.MinLength != nil || vr.Pattern != nil ||
+		vr.Minimum != nil || vr.Maximum != nil || vr.ExclusiveMinimum != nil || vr.ExclusiveMaximum != nil
 }
 
 func (vr *ValidationRules) Enabled() bool {
@@ -468,8 +473,12 @@ func collectValidators(md *ConfigMetadata, validators *[]Validator) {
 	for _, propName := range slices.Sorted(maps.Keys(md.Properties)) {
 		prop := md.Properties[propName]
 		rules := ValidationRules{
-			MaxLength: prop.MaxLength,
-			MinLength: prop.MinLength,
+			MaxLength:        prop.MaxLength,
+			MinLength:        prop.MinLength,
+			Minimum:          prop.Minimum,
+			Maximum:          prop.Maximum,
+			ExclusiveMinimum: prop.ExclusiveMinimum,
+			ExclusiveMaximum: prop.ExclusiveMaximum,
 		}
 
 		rules.Required = slices.Contains(md.Required, propName)

cmd/mdatagen/internal/cfggen/generation_test.go

@@ -1799,6 +1799,150 @@ func TestExtractValidators_StringValidators(t *testing.T) {
 	}
 }
 
+func TestExtractValidators_NumericValidators(t *testing.T) {
+	minVal := 0.0
+	maxVal := 100.0
+	exclMinVal := 5.0
+	exclMaxVal := 10.0
+
+	tests := []struct {
+		name     string
+		metadata *ConfigMetadata
+		expected []Validator
+	}{
+		{
+			name: "minimum only",
+			metadata: &ConfigMetadata{
+				Type: "object",
+				Properties: map[string]*ConfigMetadata{
+					"count": {Type: "number", Minimum: &minVal},
+				},
+			},
+			expected: []Validator{
+				{
+					FieldName: "count",
+					FieldType: "number",
+					Rules:     ValidationRules{Minimum: &minVal},
+				},
+			},
+		},
+		{
+			name: "maximum only",
+			metadata: &ConfigMetadata{
+				Type: "object",
+				Properties: map[string]*ConfigMetadata{
+					"count": {Type: "number", Maximum: &maxVal},
+				},
+			},
+			expected: []Validator{
+				{
+					FieldName: "count",
+					FieldType: "number",
+					Rules:     ValidationRules{Maximum: &maxVal},
+				},
+			},
+		},
+		{
+			name: "exclusiveMinimum only",
+			metadata: &ConfigMetadata{
+				Type: "object",
+				Properties: map[string]*ConfigMetadata{
+					"score": {Type: "number", ExclusiveMinimum: &exclMinVal},
+				},
+			},
+			expected: []Validator{
+				{
+					FieldName: "score",
+					FieldType: "number",
+					Rules:     ValidationRules{ExclusiveMinimum: &exclMinVal},
+				},
+			},
+		},
+		{
+			name: "exclusiveMaximum only",
+			metadata: &ConfigMetadata{
+				Type: "object",
+				Properties: map[string]*ConfigMetadata{
+					"score": {Type: "number", ExclusiveMaximum: &exclMaxVal},
+				},
+			},
+			expected: []Validator{
+				{
+					FieldName: "score",
+					FieldType: "number",
+					Rules:     ValidationRules{ExclusiveMaximum: &exclMaxVal},
+				},
+			},
+		},
+		{
+			name: "all numeric validators",
+			metadata: &ConfigMetadata{
+				Type: "object",
+				Properties: map[string]*ConfigMetadata{
+					"value": {Type: "number", Minimum: &minVal, Maximum: &maxVal, ExclusiveMinimum: &exclMinVal, ExclusiveMaximum: &exclMaxVal},
+				},
+			},
+			expected: []Validator{
+				{
+					FieldName: "value",
+					FieldType: "number",
+					Rules:     ValidationRules{Minimum: &minVal, Maximum: &maxVal, ExclusiveMinimum: &exclMinVal, ExclusiveMaximum: &exclMaxVal},
+				},
+			},
+		},
+		{
+			name: "integer type with numeric validators",
+			metadata: &ConfigMetadata{
+				Type: "object",
+				Properties: map[string]*ConfigMetadata{
+					"retry_count": {Type: "integer", Minimum: &minVal, Maximum: &maxVal},
+				},
+			},
+			expected: []Validator{
+				{
+					FieldName: "retry_count",
+					FieldType: "integer",
+					Rules:     ValidationRules{Minimum: &minVal, Maximum: &maxVal},
+				},
+			},
+		},
+		{
+			name: "nil numeric validators produces no validator",
+			metadata: &ConfigMetadata{
+				Type: "object",
+				Properties: map[string]*ConfigMetadata{
+					"value": {Type: "number"},
+				},
+			},
+			expected: []Validator{},
+		},
+		{
+			name: "required combined with numeric validators",
+			metadata: &ConfigMetadata{
+				Type:     "object",
+				Required: []string{"threshold"},
+				Properties: map[string]*ConfigMetadata{
+					"threshold": {Type: "number", Minimum: &minVal, Maximum: &maxVal},
+				},
+			},
+			expected: []Validator{
+				{
+					FieldName: "threshold",
+					FieldType: "number",
+					Rules:     ValidationRules{Required: true, Minimum: &minVal, Maximum: &maxVal},
+				},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := ExtractValidators(tt.metadata)
+			require.Equal(t, tt.expected, result)
+		})
+	}
+}
+
 func TestExtractValidators_InternalRefFromDefs_NoValidators(t *testing.T) {
 	md := &ConfigMetadata{
 		Ref: "plain_config",
@@ -1974,6 +2118,36 @@ func TestValidationRules_HasValueRule(t *testing.T) {
 			rules:    ValidationRules{},
 			expected: false,
 		},
+		{
+			name:     "minimum",
+			rules:    ValidationRules{Minimum: Ptr(0.0)},
+			expected: true,
+		},
+		{
+			name:     "maximum",
+			rules:    ValidationRules{Maximum: Ptr(100.0)},
+			expected: true,
+		},
+		{
+			name:     "exclusiveMinimum",
+			rules:    ValidationRules{ExclusiveMinimum: Ptr(5.0)},
+			expected: true,
+		},
+		{
+			name:     "exclusiveMaximum",
+			rules:    ValidationRules{ExclusiveMaximum: Ptr(10.0)},
+			expected: true,
+		},
+		{
+			name:     "all numeric validators",
+			rules:    ValidationRules{Minimum: Ptr(0.0), Maximum: Ptr(100.0), ExclusiveMinimum: Ptr(5.0), ExclusiveMaximum: Ptr(10.0)},
+			expected: true,
+		},
+		{
+			name:     "empty numeric validators",
+			rules:    ValidationRules{},
+			expected: false,
+		},
 	}
 
 	for _, tt := range tests {

cmd/mdatagen/internal/samplescraper/config.schema.json

@@ -621,6 +621,20 @@
             "additionalProperties": {
               "type": "string"
             }
+          },
+          "retry_count": {
+            "description": "Number of retry attempts for failed scrapes.",
+            "type": "integer",
+            "default": 3,
+            "maximum": 10,
+            "minimum": 0
+          },
+          "timeout_seconds": {
+            "description": "Timeout in seconds for each scrape request.",
+            "type": "number",
+            "default": 5,
+            "exclusiveMaximum": 30,
+            "exclusiveMinimum": 0
           }
         },
         "required": [

cmd/mdatagen/internal/samplescraper/generated_config.go

@@ -68,6 +68,18 @@ config:
             default:
               option1: value1
               option2: value2
+          retry_count:
+            description: Number of retry attempts for failed scrapes.
+            type: integer
+            default: 3
+            minimum: 0
+            maximum: 10
+          timeout_seconds:
+            description: Timeout in seconds for each scrape request.
+            type: number
+            default: 5.0
+            exclusiveMinimum: 0
+            exclusiveMaximum: 30
         required: [labels]
       default:
         - {} # one item with default values