[7.x] Add the 'X-Elastic-Client-Meta' header

Co-authored-by: Seth Michael Larson <[email protected]>

elasticsearch/_async/http_aiohttp.py

@@ -22,7 +22,11 @@ import urllib3  # type: ignore
 import warnings
 from ._extra_imports import aiohttp_exceptions, aiohttp, yarl
 from .compat import get_running_loop
-from ..connection import Connection
+from ..connection.base import (
+    Connection,
+    _get_client_meta_header,
+    _python_to_meta_version,
+)
 from ..compat import urlencode
 from ..exceptions import (
     ConnectionError,
@@ -218,6 +222,11 @@ class AIOHttpConnection(AsyncConnection):
 
         orig_body = body
         url_path = self.url_prefix + url
+        if params:
+            # Pop client metadata from parameters, if any.
+            client_meta = tuple(params.pop("_client_meta", ()))
+        else:
+            client_meta = ()
         if params:
             query_string = urlencode(params)
         else:
@@ -268,6 +277,13 @@ class AIOHttpConnection(AsyncConnection):
             body = self._gzip_compress(body)
             req_headers["content-encoding"] = "gzip"
 
+        # Create meta header for aiohttp
+        if self.meta_header:
+            client_meta = (
+                ("ai", _python_to_meta_version(aiohttp.__version__)),
+            ) + client_meta
+            req_headers["x-elastic-client-meta"] = _get_client_meta_header(client_meta)
+
         start = self.loop.time()
         try:
             async with self.session.request(