From f235f3b5064bdc6cdf2228887927a827c0dd08b2 Mon Sep 17 00:00:00 2001
From: David Ashpole <dashpole@google.com>
Date: Tue, 22 Aug 2023 17:29:33 +0000
Subject: [PATCH] map faas.* attributes to generic_task in resource mapping

---
 .../gcp_resource_detector/_constants.py       |  3 ++
 .../gcp_resource_detector/_mapping.py         | 31 ++++++++++++++++---
 .../tests/__snapshots__/test_mapping.ambr     | 11 +++++++
 .../tests/test_mapping.py                     |  9 ++++++
 4 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/opentelemetry-resourcedetector-gcp/src/opentelemetry/resourcedetector/gcp_resource_detector/_constants.py b/opentelemetry-resourcedetector-gcp/src/opentelemetry/resourcedetector/gcp_resource_detector/_constants.py
index 73ed4fd6..27f74707 100644
--- a/opentelemetry-resourcedetector-gcp/src/opentelemetry/resourcedetector/gcp_resource_detector/_constants.py
+++ b/opentelemetry-resourcedetector-gcp/src/opentelemetry/resourcedetector/gcp_resource_detector/_constants.py
@@ -35,6 +35,8 @@ class ResourceAttributes:
     SERVICE_INSTANCE_ID = "service.instance.id"
     SERVICE_NAME = "service.name"
     SERVICE_NAMESPACE = "service.namespace"
+    FAAS_INSTANCE = "faas.instance"
+    FAAS_NAME = "faas.name"
 
 
 AWS_ACCOUNT = "aws_account"
@@ -59,3 +61,4 @@ class ResourceAttributes:
 REGION = "region"
 TASK_ID = "task_id"
 ZONE = "zone"
+UNKNOWN_SERVICE_PREFIX = "unknown_service"
diff --git a/opentelemetry-resourcedetector-gcp/src/opentelemetry/resourcedetector/gcp_resource_detector/_mapping.py b/opentelemetry-resourcedetector-gcp/src/opentelemetry/resourcedetector/gcp_resource_detector/_mapping.py
index 1c22e66c..c7e107a1 100644
--- a/opentelemetry-resourcedetector-gcp/src/opentelemetry/resourcedetector/gcp_resource_detector/_mapping.py
+++ b/opentelemetry-resourcedetector-gcp/src/opentelemetry/resourcedetector/gcp_resource_detector/_mapping.py
@@ -110,8 +110,14 @@ def __init__(self, *otel_keys: str, fallback: str = ""):
             fallback="global",
         ),
         _constants.NAMESPACE: MapConfig(ResourceAttributes.SERVICE_NAMESPACE),
-        _constants.JOB: MapConfig(ResourceAttributes.SERVICE_NAME),
-        _constants.TASK_ID: MapConfig(ResourceAttributes.SERVICE_INSTANCE_ID),
+        _constants.JOB: MapConfig(
+            ResourceAttributes.SERVICE_NAME,
+            ResourceAttributes.FAAS_NAME,
+        ),
+        _constants.TASK_ID: MapConfig(
+            ResourceAttributes.SERVICE_INSTANCE_ID,
+            ResourceAttributes.FAAS_INSTANCE,
+        ),
     },
     _constants.GENERIC_NODE: {
         _constants.LOCATION: MapConfig(
@@ -169,6 +175,9 @@ def get_monitored_resource(
         if (
             ResourceAttributes.SERVICE_NAME in attrs
             and ResourceAttributes.SERVICE_INSTANCE_ID in attrs
+        ) or (
+            ResourceAttributes.FAAS_NAME in attrs
+            and ResourceAttributes.FAAS_INSTANCE in attrs
         ):
             mr = _create_monitored_resource(_constants.GENERIC_TASK, attrs)
         else:
@@ -185,10 +194,24 @@ def _create_monitored_resource(
 
     for mr_key, map_config in mapping.items():
         mr_value = None
+        fallback_value = None
         for otel_key in map_config.otel_keys:
             if otel_key in resource_attrs:
-                mr_value = resource_attrs[otel_key]
-                break
+                if  (
+                    otel_key == ResourceAttributes.SERVICE_NAME
+                    and isinstance(resource_attrs[otel_key], str)
+                    and str(resource_attrs[otel_key]).startswith(
+                        _constants.UNKNOWN_SERVICE_PREFIX
+                    )
+                ):
+                    # Only use values with an unknown_service prefix as the last resort
+                    fallback_value = resource_attrs[otel_key]
+                else:
+                    mr_value = resource_attrs[otel_key]
+                    break
+
+        if mr_value is None:
+            mr_value = fallback_value
 
         if mr_value is None:
             mr_value = map_config.fallback
diff --git a/opentelemetry-resourcedetector-gcp/tests/__snapshots__/test_mapping.ambr b/opentelemetry-resourcedetector-gcp/tests/__snapshots__/test_mapping.ambr
index 4a3f2777..ea297d8c 100644
--- a/opentelemetry-resourcedetector-gcp/tests/__snapshots__/test_mapping.ambr
+++ b/opentelemetry-resourcedetector-gcp/tests/__snapshots__/test_mapping.ambr
@@ -98,6 +98,17 @@
     'type': 'generic_task',
   })
 # ---
+# name: test_get_monitored_resource[generic task faas]
+  dict({
+    'labels': dict({
+      'job': 'faasname',
+      'location': 'myregion',
+      'namespace': 'servicens',
+      'task_id': 'faasinstance',
+    }),
+    'type': 'generic_task',
+  })
+# ---
 # name: test_get_monitored_resource[generic task fallback region]
   dict({
     'labels': dict({
diff --git a/opentelemetry-resourcedetector-gcp/tests/test_mapping.py b/opentelemetry-resourcedetector-gcp/tests/test_mapping.py
index f8ed7131..fc9262e8 100644
--- a/opentelemetry-resourcedetector-gcp/tests/test_mapping.py
+++ b/opentelemetry-resourcedetector-gcp/tests/test_mapping.py
@@ -164,6 +164,15 @@
             },
             id="generic task fallback global",
         ),
+        pytest.param(
+            {
+                "cloud.region": "myregion",
+                "service.namespace": "servicens",
+                "faas.name": "faasname",
+                "faas.instance": "faasinstance",
+            },
+            id="generic task faas",
+        ),
         # generic node
         pytest.param(
             {