resource: Allow service.version to be auto-populated by SDKs

docs/attributes-registry/service.md

@@ -10,12 +10,12 @@
 
 A service instance.
 
-| Attribute             | Type   | Description                                                                                              | Examples                               | Stability                                                        |
-| --------------------- | ------ | -------------------------------------------------------------------------------------------------------- | -------------------------------------- | ---------------------------------------------------------------- |
-| `service.instance.id` | string | The string ID of the service instance. [1]                                                               | `627cc493-f310-47de-96bd-71410b7dec09` | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
-| `service.name`        | string | Logical name of the service. [2]                                                                         | `shoppingcart`                         | ![Stable](https://img.shields.io/badge/-stable-lightgreen)       |
-| `service.namespace`   | string | A namespace for `service.name`. [3]                                                                      | `Shop`                                 | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
-| `service.version`     | string | The version string of the service API or implementation. The format is not defined by these conventions. | `2.0.0`; `a01dbef8a`                   | ![Stable](https://img.shields.io/badge/-stable-lightgreen)       |
+| Attribute             | Type   | Description                                                                                                  | Examples                               | Stability                                                        |
+| --------------------- | ------ | ------------------------------------------------------------------------------------------------------------ | -------------------------------------- | ---------------------------------------------------------------- |
+| `service.instance.id` | string | The string ID of the service instance. [1]                                                                   | `627cc493-f310-47de-96bd-71410b7dec09` | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
+| `service.name`        | string | Logical name of the service. [2]                                                                             | `shoppingcart`                         | ![Stable](https://img.shields.io/badge/-stable-lightgreen)       |
+| `service.namespace`   | string | A namespace for `service.name`. [3]                                                                          | `Shop`                                 | ![Experimental](https://img.shields.io/badge/-experimental-blue) |
+| `service.version`     | string | The version string of the service API or implementation. The format is not defined by these conventions. [4] | `2.0.0`; `a01dbef8a`                   | ![Stable](https://img.shields.io/badge/-stable-lightgreen)       |
 
 **[1]:** MUST be unique for each instance of the same `service.namespace,service.name` pair (in other words
 `service.namespace,service.name,service.instance.id` triplet MUST be globally unique). The ID helps to
@@ -47,3 +47,9 @@ port.
 **[2]:** MUST be the same for all instances of horizontally scaled services. If the value was not specified, SDKs MUST fallback to `unknown_service:` concatenated with [`process.executable.name`](process.md), e.g. `unknown_service:bash`. If `process.executable.name` is not available, the value MUST be set to `unknown_service`.
 
 **[3]:** A string value having a meaning that helps to distinguish a group of services, for example the team name that owns a group of services. `service.name` is expected to be unique within the same namespace. If `service.namespace` is not specified in the Resource then `service.name` is expected to be unique for all services that have no explicit namespace defined (so the empty/unspecified namespace is simply one more valid namespace). Zero-length namespace string is assumed equal to unspecified namespace.
+
+**[4]:** When languages/platforms offer standard ways to version applications
+and/or libraries SDKs MAY offer mechanisms to auto-populate `service.version`
+from the standard sources. If SDKs offer an auto-population mechanism it MUST be
+an optional feature users opt-into and if `service.version` is manually
+populated it MUST take priority over auto-population.

docs/resource/README.md

@@ -89,10 +89,16 @@ as specified in the [Resource SDK specification](https://github.com/open-telemet
 | Attribute  | Type | Description  | Examples  | [Requirement Level](https://opentelemetry.io/docs/specs/semconv/general/attribute-requirement-level/) | Stability |
 |---|---|---|---|---|---|
 | [`service.name`](/docs/attributes-registry/service.md) | string | Logical name of the service. [1] | `shoppingcart` | `Required` | ![Stable](https://img.shields.io/badge/-stable-lightgreen) |
-| [`service.version`](/docs/attributes-registry/service.md) | string | The version string of the service API or implementation. The format is not defined by these conventions. | `2.0.0`; `a01dbef8a` | `Recommended` | ![Stable](https://img.shields.io/badge/-stable-lightgreen) |
+| [`service.version`](/docs/attributes-registry/service.md) | string | The version string of the service API or implementation. The format is not defined by these conventions. [2] | `2.0.0`; `a01dbef8a` | `Recommended` | ![Stable](https://img.shields.io/badge/-stable-lightgreen) |
 
 **[1]:** MUST be the same for all instances of horizontally scaled services. If the value was not specified, SDKs MUST fallback to `unknown_service:` concatenated with [`process.executable.name`](process.md), e.g. `unknown_service:bash`. If `process.executable.name` is not available, the value MUST be set to `unknown_service`.
 
+**[2]:** When languages/platforms offer standard ways to version applications
+and/or libraries SDKs MAY offer mechanisms to auto-populate `service.version`
+from the standard sources. If SDKs offer an auto-population mechanism it MUST be
+an optional feature users opt-into and if `service.version` is manually
+populated it MUST take priority over auto-population.
+
 
 
 

model/registry/service.yaml

@@ -20,6 +20,12 @@ groups:
         type: string
         brief: >
           The version string of the service API or implementation. The format is not defined by these conventions.
+        note: |
+          When languages/platforms offer standard ways to version applications
+          and/or libraries SDKs MAY offer mechanisms to auto-populate `service.version`
+          from the standard sources. If SDKs offer an auto-population mechanism it MUST be
+          an optional feature users opt-into and if `service.version` is manually
+          populated it MUST take priority over auto-population.
         examples: ["2.0.0", "a01dbef8a"]
         stability: stable
       - id: service.namespace