[resource/host] Define host.mac semantic convention

CHANGELOG.md

@@ -11,6 +11,9 @@ release.
 
 ### Features
 
+- Add `host.mac` resource attribute convention.
+  ([#340](https://github.com/open-telemetry/semantic-conventions/pull/340))
+
 ### Fixes
 
 ## v1.22.0 (2023-10-12)

docs/resource/host.md

@@ -18,11 +18,14 @@ To report host metrics, the `system.*` namespace SHOULD be used.
 | `host.image.name` | string | Name of the VM image or OS install the host was instantiated from. | `infra-ami-eks-worker-node-7d4ec78312`; `CentOS-8-x86_64-1905` | Recommended |
 | `host.image.version` | string | The version string of the VM image or host OS as defined in [Version Attributes](README.md#version-attributes). | `0.1` | Recommended |
 | `host.ip` | string[] | Available IP addresses of the host, excluding loopback interfaces. [1] | `[192.168.1.140, fe80::abc2:4a28:737a:609e]` | Opt-In |
+| `host.mac` | string[] | Available MAC addresses of the host, excluding loopback interfaces. [2] | `[AC-DE-48-23-45-67, AC-DE-48-23-45-67-01-9F]` | Opt-In |
 | `host.name` | string | Name of the host. On Unix systems, it may contain what the hostname command returns, or the fully qualified hostname, or another name specified by the user. | `opentelemetry-test` | Recommended |
 | `host.type` | string | Type of host. For Cloud, this must be the machine type. | `n1-standard-1` | Recommended |
 
 **[1]:** IPv4 Addresses MUST be specified in dotted-quad notation. IPv6 addresses MUST be specified in the [RFC 5952](https://www.rfc-editor.org/rfc/rfc5952.html) format.
 
+**[2]:** MAC Addresses MUST be represented in [IEEE RA hexadecimal form](https://standards.ieee.org/wp-content/uploads/import/documents/tutorials/eui.pdf): as hyphen-separated octets in uppercase hexadecimal form from most to least significant.
+
 `host.arch` has the following list of well-known values. If one of them applies, then the respective value MUST be used, otherwise a custom value MAY be used.
 
 | Value  | Description |

model/resource/host.yaml

@@ -79,6 +79,15 @@ groups:
           IPv4 Addresses MUST be specified in dotted-quad notation. IPv6 addresses
           MUST be specified in the [RFC 5952](https://www.rfc-editor.org/rfc/rfc5952.html) format.
         examples: ["192.168.1.140", "fe80::abc2:4a28:737a:609e"]
+      - id: mac
+        type: string[]
+        requirement_level: opt_in
+        brief: >
+          Available MAC addresses of the host, excluding loopback interfaces.
+        note: >
+          MAC Addresses MUST be represented in [IEEE RA hexadecimal form](https://standards.ieee.org/wp-content/uploads/import/documents/tutorials/eui.pdf):
+          as hyphen-separated octets in uppercase hexadecimal form from most to least significant.
+        examples: ['AC-DE-48-23-45-67', 'AC-DE-48-23-45-67-01-9F']
 
   - id: host.cpu
     prefix: host.cpu