Improve url join to not mutate the base url when proxying a call (#5416)

kubelet/datadog_checks/kubelet/__init__.py

@@ -1,12 +1,13 @@
 from .__about__ import __version__
-from .common import KubeletCredentials, PodListUtils, get_pod_by_uid, is_static_pending_pod
+from .common import KubeletCredentials, PodListUtils, get_pod_by_uid, is_static_pending_pod, urljoin
 from .kubelet import KubeletCheck
 
 __all__ = [
     'KubeletCheck',
     '__version__',
     'PodListUtils',
     'KubeletCredentials',
+    'urljoin',
     'get_pod_by_uid',
     'is_static_pending_pod',
 ]

kubelet/datadog_checks/kubelet/common.py

@@ -54,6 +54,15 @@ def get_pod_by_uid(uid, podlist):
     return None
 
 
+def urljoin(*args):
+    """
+    Joins given arguments into an url. Trailing but not leading slashes are
+    stripped for each argument.
+    :return: string
+    """
+    return '/'.join(arg.strip('/') for arg in args)
+
+
 def is_static_pending_pod(pod):
     """
     Return if the pod is a static pending pod

kubelet/datadog_checks/kubelet/kubelet.py

@@ -13,7 +13,6 @@
 import requests
 from kubeutil import get_connection_info
 from six import iteritems
-from six.moves.urllib.parse import urljoin
 
 from datadog_checks.base.utils.date import UTC, parse_rfc3339
 from datadog_checks.base.utils.tagging import tagger
@@ -22,7 +21,7 @@
 from datadog_checks.errors import CheckException
 
 from .cadvisor import CadvisorScraper
-from .common import CADVISOR_DEFAULT_PORT, KubeletCredentials, PodListUtils, replace_container_rt_prefix
+from .common import CADVISOR_DEFAULT_PORT, KubeletCredentials, PodListUtils, replace_container_rt_prefix, urljoin
 from .prometheus import CadvisorPrometheusScraperMixin
 
 try:

kubelet/tests/test_common.py

@@ -9,7 +9,7 @@
 import pytest
 
 from datadog_checks.checks.openmetrics import OpenMetricsBaseCheck
-from datadog_checks.kubelet import KubeletCredentials, PodListUtils, get_pod_by_uid, is_static_pending_pod
+from datadog_checks.kubelet import KubeletCredentials, PodListUtils, get_pod_by_uid, is_static_pending_pod, urljoin
 
 from .test_kubelet import mock_from_file
 
@@ -100,6 +100,17 @@ def test_pod_by_uid():
     assert pod is None
 
 
+def test_url_join():
+    res = urljoin("https://10.100.0.1:443/api/fargate-XX.us-east-2.compute.internal/proxy", "/pods")
+    assert res == 'https://10.100.0.1:443/api/fargate-XX.us-east-2.compute.internal/proxy/pods'
+    res = urljoin("https://10.100.0.1:443/api/fargate-XX.us-east-2.compute.internal/proxy", "pods")
+    assert res == 'https://10.100.0.1:443/api/fargate-XX.us-east-2.compute.internal/proxy/pods'
+    res = urljoin("https://10.100.0.1:443/api/fargate-XX.us-east-2.compute.internal/proxy/", "pods")
+    assert res == 'https://10.100.0.1:443/api/fargate-XX.us-east-2.compute.internal/proxy/pods'
+    res = urljoin("https://10.100.0.1:443/api/fargate-XX.us-east-2.compute.internal/proxy/", "/pods")
+    assert res == 'https://10.100.0.1:443/api/fargate-XX.us-east-2.compute.internal/proxy/pods'
+
+
 def test_is_static_pod():
     podlist = json.loads(mock_from_file('pods.json'))