Centralize datetime formatting for agent

src/scout_apm/core/agent/commands.py

@@ -1,5 +1,6 @@
 # coding=utf-8
 
+import datetime as dt
 import logging
 import re
 
@@ -10,6 +11,17 @@
 key_regex = re.compile(r"^[a-zA-Z0-9]{20}$")
 
 
+def format_dt_for_core_agent(event_time: dt.datetime) -> str:
+    """
+    Returns expected format for Core Agent compatibility. Agent expects UTC datetime
+    with 'Z' suffix. Coerce any tz-aware datetime to UTC just in case.
+    """
+    # if we somehow got a non-UTC datetime, convert it to UTC
+    if event_time.tzinfo is not None:
+        event_time = event_time.astimezone(dt.timezone.utc)
+    return event_time.strftime("%Y-%m-%dT%H:%M:%SZ")
+
+
 class Register(object):
     __slots__ = ("app", "key", "hostname")
 
@@ -49,7 +61,7 @@ def __init__(self, timestamp, request_id, span_id, parent, operation):
     def message(self):
         return {
             "StartSpan": {
-                "timestamp": self.timestamp.isoformat() + "Z",
+                "timestamp": format_dt_for_core_agent(self.timestamp),
                 "request_id": self.request_id,
                 "span_id": self.span_id,
                 "parent_id": self.parent,
@@ -69,7 +81,7 @@ def __init__(self, timestamp, request_id, span_id):
     def message(self):
         return {
             "StopSpan": {
-                "timestamp": self.timestamp.isoformat() + "Z",
+                "timestamp": format_dt_for_core_agent(self.timestamp),
                 "request_id": self.request_id,
                 "span_id": self.span_id,
             }
@@ -86,7 +98,7 @@ def __init__(self, timestamp, request_id):
     def message(self):
         return {
             "StartRequest": {
-                "timestamp": self.timestamp.isoformat() + "Z",
+                "timestamp": format_dt_for_core_agent(self.timestamp),
                 "request_id": self.request_id,
             }
         }
@@ -102,7 +114,7 @@ def __init__(self, timestamp, request_id):
     def message(self):
         return {
             "FinishRequest": {
-                "timestamp": self.timestamp.isoformat() + "Z",
+                "timestamp": format_dt_for_core_agent(self.timestamp),
                 "request_id": self.request_id,
             }
         }
@@ -121,7 +133,7 @@ def __init__(self, timestamp, request_id, span_id, tag, value):
     def message(self):
         return {
             "TagSpan": {
-                "timestamp": self.timestamp.isoformat() + "Z",
+                "timestamp": format_dt_for_core_agent(self.timestamp),
                 "request_id": self.request_id,
                 "span_id": self.span_id,
                 "tag": self.tag,
@@ -142,7 +154,7 @@ def __init__(self, timestamp, request_id, tag, value):
     def message(self):
         return {
             "TagRequest": {
-                "timestamp": self.timestamp.isoformat() + "Z",
+                "timestamp": format_dt_for_core_agent(self.timestamp),
                 "request_id": self.request_id,
                 "tag": self.tag,
                 "value": self.value,
@@ -162,7 +174,7 @@ def __init__(self, event_type, event_value, source, timestamp):
     def message(self):
         return {
             "ApplicationEvent": {
-                "timestamp": self.timestamp.isoformat() + "Z",
+                "timestamp": format_dt_for_core_agent(self.timestamp),
                 "event_type": self.event_type,
                 "event_value": self.event_value,
                 "source": self.source,

src/scout_apm/core/metadata.py

@@ -4,7 +4,7 @@
 import sys
 from os import getpid
 
-from scout_apm.core.agent.commands import ApplicationEvent
+from scout_apm.core.agent.commands import ApplicationEvent, format_dt_for_core_agent
 from scout_apm.core.agent.socket import CoreAgentSocketThread
 from scout_apm.core.config import scout_config
 
@@ -24,7 +24,7 @@ def get_metadata():
     data = {
         "language": "python",
         "language_version": "{}.{}.{}".format(*sys.version_info[:3]),
-        "server_time": dt.datetime.now(dt.timezone.utc).isoformat() + "Z",
+        "server_time": format_dt_for_core_agent(dt.datetime.now(dt.timezone.utc)),
         "framework": scout_config.value("framework"),
         "framework_version": scout_config.value("framework_version"),
         "environment": "",