[chore][cmd/mdatagen] Align types for mdatagen configs

cmd/mdatagen/README.md

@@ -81,50 +81,90 @@ config:
       description: The endpoint to listen on
       default: "localhost:4317"
     timeout:
-      type: string
-      format: duration
+      type: duration
       description: Request timeout duration
       default: "30s"
     tls:
       $ref: go.opentelemetry.io/collector/config/configtls.server_config
   required: [endpoint]
 ```
 
-The `config` section is based on [JSON Schema standard](https://json-schema.org/) (draft 2020-12) and supports:
+The `config` section uses Go-centric types directly in the `type` field, and also supports:
 
-- **Standard JSON Schema types**: string, number, integer, boolean, object, array, null
 - **Validation constraints**: minLength, maxLength, pattern, minimum, maximum, enum, etc.
 - **References**: Internal (`$ref: definition_name`), external (`$ref: package.path.type`), or relative (`$ref: ./internal/config.type`)
 - **Reusable definitions**: Define common schemas in `$defs` and reference them with `$ref`
 - **Schema composition**: Use `allOf` for complex configurations
-- **Extended type aliases**: first-class aliases that expand to the correct JSON Schema shape and Go type automatically (see table below)
-
-#### Extended type aliases
-
-Instead of combining `type`+`format` or `type`+`x-customType` by hand, you can use an alias directly as the `type` value:
-
-| Alias | Go type | JSON Schema representation        |
-|---|---|-----------------------------------|
-| `rune` | `rune` | `integer`                         |
-| `byte` | `byte` | `integer`                         |
-| `uint` | `uint` | `integer`                         |
-| `int8` | `int8` | `integer`                         |
-| `uint8` | `uint8` | `integer`                         |
-| `int16` | `int16` | `integer`                         |
-| `uint16` | `uint16` | `integer`                         |
-| `int32` | `int32` | `integer`                         |
-| `uint32` | `uint32` | `integer`                         |
-| `int64` | `int64` | `integer`                         |
-| `uint64` | `uint64` | `integer`                         |
-| `float32` | `float32` | `number`                          |
-| `float64` | `float64` | `number`                          |
-| `duration` | `time.Duration` | `string` with Go duration pattern |
-| `time` | `time.Time` | `string` with `format: date-time` |
-| `opaque_string` | `configopaque.String` | `string`                          |
-| `opaque_map` | `configopaque.MapList` | `object` of name/value pairs      |
-| `id` | `component.ID` | `string`                          |
-
-Example:
+
+#### Supported types
+
+##### Primitive types
+
+Use Go type names directly in the `type` field:
+
+| Type | Go type | JSON Schema type |
+|------|---------|-----------------|
+| `string` | `string` | `string` |
+| `bool` | `bool` | `boolean` |
+| `int` | `int` | `integer` |
+| `int8` | `int8` | `integer` |
+| `int16` | `int16` | `integer` |
+| `int32` | `int32` | `integer` |
+| `int64` | `int64` | `integer` |
+| `uint` | `uint` | `integer` |
+| `uint8` | `uint8` | `integer` |
+| `uint16` | `uint16` | `integer` |
+| `uint32` | `uint32` | `integer` |
+| `uint64` | `uint64` | `integer` |
+| `byte` | `byte` | `integer` |
+| `rune` | `rune` | `integer` |
+| `float32` | `float32` | `number` |
+| `float64` | `float64` | `number` |
+| `any` | `any` | *(no type constraint)* |
+
+##### Container types
+
+| Type | Go type | JSON Schema type | Notes |
+|------|---------|-----------------|-------|
+| `object` | struct | `object` | Requires `properties:` |
+| `slice` | `[]T` | `array` | Requires `values:` for the element type |
+| `map` | `map[string]T` | `object` | Requires `values:` for the value type |
+
+Example using container types:
+
+```yaml
+config:
+  type: object
+  properties:
+    endpoints:
+      type: slice
+      values:
+        type: string
+      description: List of endpoints to connect to.
+    headers:
+      type: map
+      values:
+        type: string
+      description: Extra HTTP headers to attach to each request.
+    tls:
+      $ref: go.opentelemetry.io/collector/config/configtls.server_config
+```
+
+##### Alias types
+
+Shorthand types that expand to a primitive or container type with additional annotations:
+
+| Alias | Go type | JSON Schema representation | Notes |
+|-------|---------|---------------------------|-------|
+| `float` | `float32` | `number` | Shorthand for `float32` |
+| `double` | `float64` | `number` | Shorthand for `float64` |
+| `duration` | `time.Duration` | `string` with Go duration pattern | e.g. `"30s"`, `"1h30m"` |
+| `time` | `time.Time` | `string` with `format: date-time` | RFC 3339 format |
+| `opaque_string` | `configopaque.String` | `string` | Masked in logs |
+| `component_id` | `component.ID` | `string` | Collector component ID |
+| `opaque_map` | `configopaque.MapList` | `object` of name/value pairs | Values masked in logs |
+
+Example using alias types:
 
 ```yaml
 config:
@@ -140,8 +180,6 @@ config:
       type: opaque_string
 ```
 
-Aliases are additive: existing uses of standard JSON Schema types, `format`, and `x-customType` remain supported without migration.
-
 ### Metrics Builder Configuration
 
 For receivers, scrapers, and other components that emit metrics, `mdatagen` can generate metrics builder
@@ -172,7 +210,7 @@ metrics:
     description: Number of received requests.
     unit: "{request}"
     sum:
-      value_type: int
+      values: int
       monotonic: true
       aggregation_temporality: cumulative
     attributes: [status_code]

cmd/mdatagen/internal/cfggen/docgen.go

@@ -111,24 +111,18 @@ func CfgDocType(cfg *ConfigMetadata) string {
 			return "string (one of: " + strings.Join(vals, ", ") + ")"
 		}
 		return "string"
-	case "integer":
-		return "int"
-	case "number":
-		return "float"
-	case "boolean":
-		return "bool"
-	case "array":
-		if cfg.Items != nil {
-			return "[]" + CfgDocType(cfg.Items)
+	case "slice":
+		if cfg.Values != nil {
+			return "[]" + CfgDocType(cfg.Values)
 		}
 		return "[]any"
-	case "object":
-		if cfg.AdditionalProperties != nil {
-			return "map[string]" + CfgDocType(cfg.AdditionalProperties)
+	case "map":
+		if cfg.Values != nil {
+			return "map[string]" + CfgDocType(cfg.Values)
 		}
-		return "object"
+		return "map[string]any"
 	default:
-		return "any"
+		return cfg.Type
 	}
 }
 

cmd/mdatagen/internal/cfggen/docgen_test.go

@@ -107,10 +107,10 @@ func TestCfgIsObject(t *testing.T) {
 	}{
 		{"nil", nil, false},
 		{"primitive string", &ConfigMetadata{Type: "string"}, false},
-		{"array of strings", &ConfigMetadata{Type: "array", Items: &ConfigMetadata{Type: "string"}}, false},
+		{"slice of strings", &ConfigMetadata{Type: "slice", Values: &ConfigMetadata{Type: "string"}}, false},
 		{"inline object", &ConfigMetadata{Type: "object", Properties: map[string]*ConfigMetadata{"x": {Type: "string"}}}, true},
 		{"ref-resolved object", &ConfigMetadata{Type: "object", Ref: "confighttp.ServerConfig", Properties: map[string]*ConfigMetadata{"port": {Type: "integer"}}}, true},
-		{"map without properties", &ConfigMetadata{Type: "object", AdditionalProperties: &ConfigMetadata{Type: "string"}}, false},
+		{"map without properties", &ConfigMetadata{Type: "map", Values: &ConfigMetadata{Type: "string"}}, false},
 	}
 	for _, tc := range cases {
 		t.Run(tc.name, func(t *testing.T) {
@@ -140,15 +140,15 @@ func TestCfgDocType(t *testing.T) {
 		{"datetime via GoType", &ConfigMetadata{Type: "string", GoType: "time.Time"}, "datetime"},
 		{"datetime via Format", &ConfigMetadata{Type: "string", Format: "date-time"}, "datetime"},
 		{"enum string", &ConfigMetadata{Type: "string", Enum: []any{"a", "b"}}, "string (one of: a, b)"},
-		{"integer", &ConfigMetadata{Type: "integer"}, "int"},
-		{"number", &ConfigMetadata{Type: "number"}, "float"},
-		{"boolean", &ConfigMetadata{Type: "boolean"}, "bool"},
-		{"array of string", &ConfigMetadata{Type: "array", Items: &ConfigMetadata{Type: "string"}}, "[]string"},
-		{"array of any", &ConfigMetadata{Type: "array"}, "[]any"},
-		{"map of string", &ConfigMetadata{Type: "object", AdditionalProperties: &ConfigMetadata{Type: "string"}}, "map[string]string"},
+		{"int", &ConfigMetadata{Type: "int"}, "int"},
+		{"float64", &ConfigMetadata{Type: "float64"}, "float64"},
+		{"bool", &ConfigMetadata{Type: "bool"}, "bool"},
+		{"array of string", &ConfigMetadata{Type: "slice", Values: &ConfigMetadata{Type: "string"}}, "[]string"},
+		{"array of any", &ConfigMetadata{Type: "slice"}, "[]any"},
+		{"map of string", &ConfigMetadata{Type: "map", Values: &ConfigMetadata{Type: "string"}}, "map[string]string"},
 		{"inline object", &ConfigMetadata{Type: "object", Properties: map[string]*ConfigMetadata{"x": {Type: "string"}}}, "object"},
 		{"plain object no props", &ConfigMetadata{Type: "object"}, "object"},
-		{"unknown type", &ConfigMetadata{Type: "unknown"}, "any"},
+		{"unknown type", &ConfigMetadata{Type: "unknown"}, "unknown"},
 	}
 	for _, tc := range cases {
 		t.Run(tc.name, func(t *testing.T) {