[7.x] Surface deprecation warnings from Elasticsearch

elasticsearch/__init__.py

@@ -6,17 +6,7 @@ __version__ = VERSION
 __versionstr__ = ".".join(map(str, VERSION))
 
 import logging
-
+import warnings
-try:  # Python 2.7+
-    from logging import NullHandler
-except ImportError:
-
-    class NullHandler(logging.Handler):
-        def emit(self, record):
-            pass
-
-
-import sys
 
 logger = logging.getLogger("elasticsearch")
 logger.addHandler(logging.NullHandler())
@@ -26,4 +16,47 @@ from .transport import Transport
 from .connection_pool import ConnectionPool, ConnectionSelector, RoundRobinSelector
 from .serializer import JSONSerializer
 from .connection import Connection, RequestsHttpConnection, Urllib3HttpConnection
-from .exceptions import *
+from .exceptions import (
+    ImproperlyConfigured,
+    ElasticsearchException,
+    SerializationError,
+    TransportError,
+    NotFoundError,
+    ConflictError,
+    RequestError,
+    ConnectionError,
+    SSLError,
+    ConnectionTimeout,
+    AuthenticationException,
+    AuthorizationException,
+    ElasticsearchDeprecationWarning,
+)
+
+# Only raise one warning per deprecation message so as not
+# to spam up the user if the same action is done multiple times.
+warnings.simplefilter("default", category=ElasticsearchDeprecationWarning, append=True)
+
+__all__ = [
+    "Elasticsearch",
+    "Transport",
+    "ConnectionPool",
+    "ConnectionSelector",
+    "RoundRobinSelector",
+    "JSONSerializer",
+    "Connection",
+    "RequestsHttpConnection",
+    "Urllib3HttpConnection",
+    "ImproperlyConfigured",
+    "ElasticsearchException",
+    "SerializationError",
+    "TransportError",
+    "NotFoundError",
+    "ConflictError",
+    "RequestError",
+    "ConnectionError",
+    "SSLError",
+    "ConnectionTimeout",
+    "AuthenticationException",
+    "AuthorizationException",
+    "ElasticsearchDeprecationWarning",
+]

elasticsearch/connection/base.py

@@ -2,14 +2,21 @@ import logging
 import binascii
 import gzip
 import io
+import re
 from platform import python_version
+import warnings
 
 try:
     import simplejson as json
 except ImportError:
     import json
 
-from ..exceptions import TransportError, ImproperlyConfigured, HTTP_EXCEPTIONS
+from ..exceptions import (
+    TransportError,
+    ImproperlyConfigured,
+    ElasticsearchDeprecationWarning,
+    HTTP_EXCEPTIONS,
+)
 from .. import __versionstr__
 
 logger = logging.getLogger("elasticsearch")
@@ -21,6 +28,8 @@ tracer = logging.getLogger("elasticsearch.trace")
 if not _tracer_already_configured:
     tracer.propagate = False
 
+_WARNING_RE = re.compile(r"\"([^\"]*)\"")
+
 
 class Connection(object):
     """
@@ -132,6 +141,35 @@ class Connection(object):
             f.write(body)
         return buf.getvalue()
 
+    def _raise_warnings(self, warning_headers):
+        """If 'headers' contains a 'Warning' header raise
+        the warnings to be seen by the user. Takes an iterable
+        of string values from any number of 'Warning' headers.
+        """
+        if not warning_headers:
+            return
+
+        # Grab only the message from each header, the rest is discarded.
+        # Format is: '(number) Elasticsearch-(version)-(instance) "(message)"'
+        warning_messages = []
+        for header in warning_headers:
+            # Because 'Requests' does it's own folding of multiple HTTP headers
+            # into one header delimited by commas (totally standard compliant, just
+            # annoying for cases like this) we need to expect there may be
+            # more than one message per 'Warning' header.
+            matches = _WARNING_RE.findall(header)
+            if matches:
+                warning_messages.extend(matches)
+            else:
+                # Don't want to throw away any warnings, even if they
+                # don't follow the format we have now. Use the whole header.
+                warning_messages.append(header)
+
+        for message in warning_messages:
+            warnings.warn(
+                message, category=ElasticsearchDeprecationWarning, stacklevel=6
+            )
+
     def _pretty_json(self, data):
         # pretty JSON in tracer curl logs
         try:

elasticsearch/connection/http_requests.py

@@ -156,6 +156,12 @@ class RequestsHttpConnection(Connection):
                 raise ConnectionTimeout("TIMEOUT", str(e), e)
             raise ConnectionError("N/A", str(e), e)
 
+        # raise warnings if any from the 'Warnings' header.
+        warnings_headers = (
+            (response.headers["warning"],) if "warning" in response.headers else ()
+        )
+        self._raise_warnings(warnings_headers)
+
         # raise errors based on http status codes, let the client handle those if needed
         if (
             not (200 <= response.status_code < 300)

elasticsearch/connection/http_urllib3.py

@@ -240,6 +240,10 @@ class Urllib3HttpConnection(Connection):
                 raise ConnectionTimeout("TIMEOUT", str(e), e)
             raise ConnectionError("N/A", str(e), e)
 
+        # raise warnings if any from the 'Warnings' header.
+        warning_headers = response.headers.get_all("warning", ())
+        self._raise_warnings(warning_headers)
+
         # raise errors based on http status codes, let the client handle those if needed
         if not (200 <= response.status < 300) and response.status not in ignore:
             self.log_request_fail(

elasticsearch/exceptions.py

@@ -136,6 +136,12 @@ class AuthorizationException(TransportError):
     """ Exception representing a 403 status code. """
 
 
+class ElasticsearchDeprecationWarning(Warning):
+    """ Warning that is raised when a deprecated option
+    is flagged via the 'Warning' HTTP header.
+    """
+
+
 # more generic mappings from status_code to python exceptions
 HTTP_EXCEPTIONS = {
     400: RequestError,

elasticsearch/helpers/test.py

@@ -51,9 +51,15 @@ class ElasticsearchTestCase(TestCase):
 
     def tearDown(self):
         super(ElasticsearchTestCase, self).tearDown()
-        self.client.indices.delete(index="*", ignore=404)
+        # Hidden indices expanded in wildcards in ES 7.7
+        expand_wildcards = ["open", "closed"]
+        if self.es_version >= (7, 7):
+            expand_wildcards.append("hidden")
+
+        self.client.indices.delete(
+            index="*", ignore=404, expand_wildcards=expand_wildcards
+        )
         self.client.indices.delete_template(name="*", ignore=404)
-        self.client.indices.delete_alias(index="_all", name="_all", ignore=404)
 
     @property
     def es_version(self):

test_elasticsearch/test_connection.py

@@ -4,6 +4,7 @@ import gzip
 import io
 from mock import Mock, patch
 import urllib3
+from urllib3._collections import HTTPHeaderDict
 import warnings
 from requests.auth import AuthBase
 from platform import python_version
@@ -87,6 +88,48 @@ class TestBaseConnection(TestCase):
             "8af7ee35420f458e903026b4064081f2.westeurope.azure.elastic-cloud.com",
         )
 
+    def test_empty_warnings(self):
+        con = Connection()
+        with warnings.catch_warnings(record=True) as w:
+            con._raise_warnings(())
+            con._raise_warnings([])
+
+        self.assertEquals(w, [])
+
+    def test_raises_warnings(self):
+        con = Connection()
+
+        with warnings.catch_warnings(record=True) as warn:
+            con._raise_warnings(['299 Elasticsearch-7.6.1-aa751 "this is deprecated"'])
+
+        self.assertEquals([str(w.message) for w in warn], ["this is deprecated"])
+
+        with warnings.catch_warnings(record=True) as warn:
+            con._raise_warnings(
+                [
+                    '299 Elasticsearch-7.6.1-aa751 "this is also deprecated"',
+                    '299 Elasticsearch-7.6.1-aa751 "this is also deprecated"',
+                    '299 Elasticsearch-7.6.1-aa751 "guess what? deprecated"',
+                ]
+            )
+
+        self.assertEquals(
+            [str(w.message) for w in warn],
+            ["this is also deprecated", "guess what? deprecated"],
+        )
+
+    def test_raises_warnings_when_folded(self):
+        con = Connection()
+        with warnings.catch_warnings(record=True) as warn:
+            con._raise_warnings(
+                [
+                    '299 Elasticsearch-7.6.1-aa751 "warning",'
+                    '299 Elasticsearch-7.6.1-aa751 "folded"',
+                ]
+            )
+
+        self.assertEquals([str(w.message) for w in warn], ["warning", "folded"])
+
 
 class TestUrllib3Connection(TestCase):
     def _get_mock_connection(self, connection_params={}, response_body=b"{}"):
@@ -94,7 +137,7 @@ class TestUrllib3Connection(TestCase):
 
         def _dummy_urlopen(*args, **kwargs):
             dummy_response = Mock()
-            dummy_response.headers = {}
+            dummy_response.headers = HTTPHeaderDict({})
             dummy_response.status = 200
             dummy_response.data = response_body
             _dummy_urlopen.call_args = (args, kwargs)

test_elasticsearch/test_server/test_common.py

@@ -8,8 +8,9 @@ from os import walk, environ
 from os.path import exists, join, dirname, pardir
 import yaml
 from shutil import rmtree
+import warnings
 
-from elasticsearch import TransportError, RequestError
+from elasticsearch import TransportError, RequestError, ElasticsearchDeprecationWarning
 from elasticsearch.compat import string_types
 from elasticsearch.helpers.test import _get_version
 
@@ -30,6 +31,7 @@ IMPLEMENTED_FEATURES = {
     "headers",
     "catch_unauthorized",
     "default_shards",
+    "warnings",
 }
 
 # broken YAML tests on some releases
@@ -40,6 +42,8 @@ SKIP_TESTS = {
         # Disallowing expensive queries is 7.7+
         "TestSearch320DisallowQueries",
         "TestIndicesPutIndexTemplate10Basic",
+        "TestIndicesGetIndexTemplate10Basic",
+        "TestIndicesGetIndexTemplate20GetMissing",
     }
 }
 
@@ -150,6 +154,7 @@ class YamlTestCase(ElasticsearchTestCase):
 
     def run_code(self, test):
         """ Execute an instruction based on it's type. """
+        print(test)
         for action in test:
             self.assertEquals(1, len(action))
             action_type, action = list(action.items())[0]
@@ -164,6 +169,7 @@ class YamlTestCase(ElasticsearchTestCase):
         api = self.client
         headers = action.pop("headers", None)
         catch = action.pop("catch", None)
+        warn = action.pop("warnings", None)
         self.assertEquals(1, len(action))
 
         method, args = list(action.items())[0]
@@ -184,6 +190,8 @@ class YamlTestCase(ElasticsearchTestCase):
         for k in args:
             args[k] = self._resolve(args[k])
 
+        warnings.simplefilter("always", category=ElasticsearchDeprecationWarning)
+        with warnings.catch_warnings(record=True) as caught_warnings:
             try:
                 self.last_response = api(**args)
             except Exception as e:
@@ -196,6 +204,21 @@ class YamlTestCase(ElasticsearchTestCase):
                         "Failed to catch %r in %r." % (catch, self.last_response)
                     )
 
+        # Filter out warnings raised by other components.
+        caught_warnings = [
+            str(w.message)
+            for w in caught_warnings
+            if w.category == ElasticsearchDeprecationWarning
+        ]
+
+        # Sorting removes the issue with order raised. We only care about
+        # if all warnings are raised in the single API call.
+        if warn is not None and sorted(warn) != sorted(caught_warnings):
+            raise AssertionError(
+                "Expected warnings not equal to actual warnings: expected=%r actual=%r"
+                % (warn, caught_warnings)
+            )
+
     def _get_nodes(self):
         if not hasattr(self, "_node_info"):
             self._node_info = list(

tox.ini

@@ -7,15 +7,20 @@ setenv =
 commands =
     python setup.py test
 
-[testenv:lint]
+[testenv:blacken]
 deps =
-    flake8
     black
 commands =
     black --target-version=py27 \
         elasticsearch/ \
         test_elasticsearch/ \
         setup.py
+
+[testenv:lint]
+deps =
+    flake8
+    black
+commands =
     black --target-version=py27 --check \
         elasticsearch/ \
         test_elasticsearch/ \