prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  Expand k8s pod ID discovery regex
  Implementing elastic/apm#344
  
  --- END ISSUE ---
  
  Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
  --- BEGIN FILES ---
  Path: `elasticapm/utils/cgroup.py`
  Content:
  ```
  1 #  BSD 3-Clause License
  2 #
  3 #  Copyright (c) 2019, Elasticsearch BV
  4 #  All rights reserved.
  5 #
  6 #  Redistribution and use in source and binary forms, with or without
  7 #  modification, are permitted provided that the following conditions are met:
  8 #
  9 #  * Redistributions of source code must retain the above copyright notice, this
  10 #    list of conditions and the following disclaimer.
  11 #
  12 #  * Redistributions in binary form must reproduce the above copyright notice,
  13 #    this list of conditions and the following disclaimer in the documentation
  14 #    and/or other materials provided with the distribution.
  15 #
  16 #  * Neither the name of the copyright holder nor the names of its
  17 #    contributors may be used to endorse or promote products derived from
  18 #    this software without specific prior written permission.
  19 #
  20 #  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  21 #  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22 #  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  23 #  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  24 #  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25 #  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  26 #  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  27 #  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  28 #  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29 #  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30 
  31 import os
  32 import re
  33 
  34 CGROUP_PATH = "/proc/self/cgroup"
  35 
  36 SYSTEMD_SCOPE_SUFFIX = ".scope"
  37 
  38 kubepods_regexp = re.compile(
  39     r"(?:^/kubepods[\S]*/pod([^/]+)$)|(?:^/kubepods\.slice/kubepods-[^/]+\.slice/kubepods-[^/]+-pod([^/]+)\.slice$)"
  40 )
  41 
  42 container_id_regexp = re.compile(
  43     "^(?:[0-9a-f]{64}|[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4,})$", re.IGNORECASE
  44 )
  45 
  46 
  47 def get_cgroup_container_metadata():
  48     """
  49     Reads docker/kubernetes metadata (container id, pod id) from /proc/self/cgroup
  50 
  51     The result is a nested dictionary with the detected IDs, e.g.
  52 
  53         {
  54             "container": {"id": "2227daf62df6694645fee5df53c1f91271546a9560e8600a525690ae252b7f63"},
  55             "pod": {"uid": "90d81341_92de_11e7_8cf2_507b9d4141fa"}
  56         }
  57 
  58     :return: a dictionary with the detected ids or {}
  59     """
  60     if not os.path.exists(CGROUP_PATH):
  61         return {}
  62     with open(CGROUP_PATH) as f:
  63         return parse_cgroups(f) or {}
  64 
  65 
  66 def parse_cgroups(filehandle):
  67     """
  68     Reads lines from a file handle and tries to parse docker container IDs and kubernetes Pod IDs.
  69 
  70     See tests.utils.docker_tests.test_cgroup_parsing for a set of test cases
  71 
  72     :param filehandle:
  73     :return: nested dictionary or None
  74     """
  75     for line in filehandle:
  76         parts = line.strip().split(":")
  77         if len(parts) != 3:
  78             continue
  79         cgroup_path = parts[2]
  80 
  81         # Depending on the filesystem driver used for cgroup
  82         # management, the paths in /proc/pid/cgroup will have
  83         # one of the following formats in a Docker container:
  84         #
  85         #   systemd: /system.slice/docker-<container-ID>.scope
  86         #   cgroupfs: /docker/<container-ID>
  87         #
  88         # In a Kubernetes pod, the cgroup path will look like:
  89         #
  90         #   systemd:/kubepods.slice/kubepods-<QoS-class>.slice/kubepods-<QoS-class>-pod<pod-UID>.slice/<container-iD>.scope
  91         #   cgroupfs:/kubepods/<QoS-class>/pod<pod-UID>/<container-iD>
  92 
  93         directory, container_id = os.path.split(cgroup_path)
  94         if container_id.endswith(SYSTEMD_SCOPE_SUFFIX):
  95             container_id = container_id[: -len(SYSTEMD_SCOPE_SUFFIX)]
  96             if "-" in container_id:
  97                 container_id = container_id.split("-", 1)[1]
  98         kubepods_match = kubepods_regexp.match(directory)
  99         if kubepods_match:
  100             pod_id = kubepods_match.group(1)
  101             if not pod_id:
  102                 pod_id = kubepods_match.group(2)
  103                 if pod_id:
  104                     pod_id = pod_id.replace("_", "-")
  105             return {"container": {"id": container_id}, "kubernetes": {"pod": {"uid": pod_id}}}
  106         elif container_id_regexp.match(container_id):
  107             return {"container": {"id": container_id}}
  108
  ```
  --- END FILES ---
  
  Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.
  
  Here is an example:
  
  ```diff
  diff --git a/examples/server_async.py b/examples/server_async.py
  --- a/examples/server_async.py
  +++ b/examples/server_async.py
  @@ -313,4 +313,4 @@
   
   
   if __name__ == "__main__":
  -    asyncio.run(run_async_server("."), debug=True)
  +    asyncio.run(run_async_server(), debug=True)
  diff --git a/examples/server_sync.py b/examples/server_sync.py
  --- a/examples/server_sync.py
  +++ b/examples/server_sync.py
  @@ -313,5 +313,5 @@
   
   
   if __name__ == "__main__":
  -    server = run_sync_server(".")
  +    server = run_sync_server()
       server.shutdown()
  
  ```
  
golden_diff: diff --git a/elasticapm/utils/cgroup.py b/elasticapm/utils/cgroup.py
  --- a/elasticapm/utils/cgroup.py
  +++ b/elasticapm/utils/cgroup.py
  @@ -36,7 +36,7 @@
   SYSTEMD_SCOPE_SUFFIX = ".scope"
   
   kubepods_regexp = re.compile(
  -    r"(?:^/kubepods[\S]*/pod([^/]+)$)|(?:^/kubepods\.slice/kubepods-[^/]+\.slice/kubepods-[^/]+-pod([^/]+)\.slice$)"
  +    r"(?:^/kubepods[\S]*/pod([^/]+)$)|(?:^/kubepods\.slice/(kubepods-[^/]+\.slice/)?kubepods[^/]*-pod([^/]+)\.slice$)"
   )
   
   container_id_regexp = re.compile(
  @@ -97,9 +97,9 @@
                   container_id = container_id.split("-", 1)[1]
           kubepods_match = kubepods_regexp.match(directory)
           if kubepods_match:
  -            pod_id = kubepods_match.group(1)
  +            pod_id = kubepods_match.group(1)  # if first part of kubepods_regexp matched
               if not pod_id:
  -                pod_id = kubepods_match.group(2)
  +                pod_id = kubepods_match.group(3)  # if second part of kubepods_regexp matched
                   if pod_id:
                       pod_id = pod_id.replace("_", "-")
               return {"container": {"id": container_id}, "kubernetes": {"pod": {"uid": pod_id}}}
  
verification_info: {"golden_diff": "diff --git a/elasticapm/utils/cgroup.py b/elasticapm/utils/cgroup.py\n--- a/elasticapm/utils/cgroup.py\n+++ b/elasticapm/utils/cgroup.py\n@@ -36,7 +36,7 @@\n SYSTEMD_SCOPE_SUFFIX = \".scope\"\n \n kubepods_regexp = re.compile(\n-    r\"(?:^/kubepods[\\S]*/pod([^/]+)$)|(?:^/kubepods\\.slice/kubepods-[^/]+\\.slice/kubepods-[^/]+-pod([^/]+)\\.slice$)\"\n+    r\"(?:^/kubepods[\\S]*/pod([^/]+)$)|(?:^/kubepods\\.slice/(kubepods-[^/]+\\.slice/)?kubepods[^/]*-pod([^/]+)\\.slice$)\"\n )\n \n container_id_regexp = re.compile(\n@@ -97,9 +97,9 @@\n                 container_id = container_id.split(\"-\", 1)[1]\n         kubepods_match = kubepods_regexp.match(directory)\n         if kubepods_match:\n-            pod_id = kubepods_match.group(1)\n+            pod_id = kubepods_match.group(1)  # if first part of kubepods_regexp matched\n             if not pod_id:\n-                pod_id = kubepods_match.group(2)\n+                pod_id = kubepods_match.group(3)  # if second part of kubepods_regexp matched\n                 if pod_id:\n                     pod_id = pod_id.replace(\"_\", \"-\")\n             return {\"container\": {\"id\": container_id}, \"kubernetes\": {\"pod\": {\"uid\": pod_id}}}\n", "issue": "Expand k8s pod ID discovery regex\nImplementing elastic/apm#344\n", "before_files": [{"content": "#  BSD 3-Clause License\n#\n#  Copyright (c) 2019, Elasticsearch BV\n#  All rights reserved.\n#\n#  Redistribution and use in source and binary forms, with or without\n#  modification, are permitted provided that the following conditions are met:\n#\n#  * Redistributions of source code must retain the above copyright notice, this\n#    list of conditions and the following disclaimer.\n#\n#  * Redistributions in binary form must reproduce the above copyright notice,\n#    this list of conditions and the following disclaimer in the documentation\n#    and/or other materials provided with the distribution.\n#\n#  * Neither the name of the copyright holder nor the names of its\n#    contributors may be used to endorse or promote products derived from\n#    this software without specific prior written permission.\n#\n#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS \"AS IS\"\n#  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE\n#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE\n#  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE\n#  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL\n#  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR\n#  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER\n#  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,\n#  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE\n#  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.\n\nimport os\nimport re\n\nCGROUP_PATH = \"/proc/self/cgroup\"\n\nSYSTEMD_SCOPE_SUFFIX = \".scope\"\n\nkubepods_regexp = re.compile(\n    r\"(?:^/kubepods[\\S]*/pod([^/]+)$)|(?:^/kubepods\\.slice/kubepods-[^/]+\\.slice/kubepods-[^/]+-pod([^/]+)\\.slice$)\"\n)\n\ncontainer_id_regexp = re.compile(\n    \"^(?:[0-9a-f]{64}|[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4,})$\", re.IGNORECASE\n)\n\n\ndef get_cgroup_container_metadata():\n    \"\"\"\n    Reads docker/kubernetes metadata (container id, pod id) from /proc/self/cgroup\n\n    The result is a nested dictionary with the detected IDs, e.g.\n\n        {\n            \"container\": {\"id\": \"2227daf62df6694645fee5df53c1f91271546a9560e8600a525690ae252b7f63\"},\n            \"pod\": {\"uid\": \"90d81341_92de_11e7_8cf2_507b9d4141fa\"}\n        }\n\n    :return: a dictionary with the detected ids or {}\n    \"\"\"\n    if not os.path.exists(CGROUP_PATH):\n        return {}\n    with open(CGROUP_PATH) as f:\n        return parse_cgroups(f) or {}\n\n\ndef parse_cgroups(filehandle):\n    \"\"\"\n    Reads lines from a file handle and tries to parse docker container IDs and kubernetes Pod IDs.\n\n    See tests.utils.docker_tests.test_cgroup_parsing for a set of test cases\n\n    :param filehandle:\n    :return: nested dictionary or None\n    \"\"\"\n    for line in filehandle:\n        parts = line.strip().split(\":\")\n        if len(parts) != 3:\n            continue\n        cgroup_path = parts[2]\n\n        # Depending on the filesystem driver used for cgroup\n        # management, the paths in /proc/pid/cgroup will have\n        # one of the following formats in a Docker container:\n        #\n        #   systemd: /system.slice/docker-<container-ID>.scope\n        #   cgroupfs: /docker/<container-ID>\n        #\n        # In a Kubernetes pod, the cgroup path will look like:\n        #\n        #   systemd:/kubepods.slice/kubepods-<QoS-class>.slice/kubepods-<QoS-class>-pod<pod-UID>.slice/<container-iD>.scope\n        #   cgroupfs:/kubepods/<QoS-class>/pod<pod-UID>/<container-iD>\n\n        directory, container_id = os.path.split(cgroup_path)\n        if container_id.endswith(SYSTEMD_SCOPE_SUFFIX):\n            container_id = container_id[: -len(SYSTEMD_SCOPE_SUFFIX)]\n            if \"-\" in container_id:\n                container_id = container_id.split(\"-\", 1)[1]\n        kubepods_match = kubepods_regexp.match(directory)\n        if kubepods_match:\n            pod_id = kubepods_match.group(1)\n            if not pod_id:\n                pod_id = kubepods_match.group(2)\n                if pod_id:\n                    pod_id = pod_id.replace(\"_\", \"-\")\n            return {\"container\": {\"id\": container_id}, \"kubernetes\": {\"pod\": {\"uid\": pod_id}}}\n        elif container_id_regexp.match(container_id):\n            return {\"container\": {\"id\": container_id}}\n", "path": "elasticapm/utils/cgroup.py"}], "after_files": [{"content": "#  BSD 3-Clause License\n#\n#  Copyright (c) 2019, Elasticsearch BV\n#  All rights reserved.\n#\n#  Redistribution and use in source and binary forms, with or without\n#  modification, are permitted provided that the following conditions are met:\n#\n#  * Redistributions of source code must retain the above copyright notice, this\n#    list of conditions and the following disclaimer.\n#\n#  * Redistributions in binary form must reproduce the above copyright notice,\n#    this list of conditions and the following disclaimer in the documentation\n#    and/or other materials provided with the distribution.\n#\n#  * Neither the name of the copyright holder nor the names of its\n#    contributors may be used to endorse or promote products derived from\n#    this software without specific prior written permission.\n#\n#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS \"AS IS\"\n#  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE\n#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE\n#  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE\n#  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL\n#  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR\n#  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER\n#  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,\n#  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE\n#  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.\n\nimport os\nimport re\n\nCGROUP_PATH = \"/proc/self/cgroup\"\n\nSYSTEMD_SCOPE_SUFFIX = \".scope\"\n\nkubepods_regexp = re.compile(\n    r\"(?:^/kubepods[\\S]*/pod([^/]+)$)|(?:^/kubepods\\.slice/(kubepods-[^/]+\\.slice/)?kubepods[^/]*-pod([^/]+)\\.slice$)\"\n)\n\ncontainer_id_regexp = re.compile(\n    \"^(?:[0-9a-f]{64}|[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4,})$\", re.IGNORECASE\n)\n\n\ndef get_cgroup_container_metadata():\n    \"\"\"\n    Reads docker/kubernetes metadata (container id, pod id) from /proc/self/cgroup\n\n    The result is a nested dictionary with the detected IDs, e.g.\n\n        {\n            \"container\": {\"id\": \"2227daf62df6694645fee5df53c1f91271546a9560e8600a525690ae252b7f63\"},\n            \"pod\": {\"uid\": \"90d81341_92de_11e7_8cf2_507b9d4141fa\"}\n        }\n\n    :return: a dictionary with the detected ids or {}\n    \"\"\"\n    if not os.path.exists(CGROUP_PATH):\n        return {}\n    with open(CGROUP_PATH) as f:\n        return parse_cgroups(f) or {}\n\n\ndef parse_cgroups(filehandle):\n    \"\"\"\n    Reads lines from a file handle and tries to parse docker container IDs and kubernetes Pod IDs.\n\n    See tests.utils.docker_tests.test_cgroup_parsing for a set of test cases\n\n    :param filehandle:\n    :return: nested dictionary or None\n    \"\"\"\n    for line in filehandle:\n        parts = line.strip().split(\":\")\n        if len(parts) != 3:\n            continue\n        cgroup_path = parts[2]\n\n        # Depending on the filesystem driver used for cgroup\n        # management, the paths in /proc/pid/cgroup will have\n        # one of the following formats in a Docker container:\n        #\n        #   systemd: /system.slice/docker-<container-ID>.scope\n        #   cgroupfs: /docker/<container-ID>\n        #\n        # In a Kubernetes pod, the cgroup path will look like:\n        #\n        #   systemd:/kubepods.slice/kubepods-<QoS-class>.slice/kubepods-<QoS-class>-pod<pod-UID>.slice/<container-iD>.scope\n        #   cgroupfs:/kubepods/<QoS-class>/pod<pod-UID>/<container-iD>\n\n        directory, container_id = os.path.split(cgroup_path)\n        if container_id.endswith(SYSTEMD_SCOPE_SUFFIX):\n            container_id = container_id[: -len(SYSTEMD_SCOPE_SUFFIX)]\n            if \"-\" in container_id:\n                container_id = container_id.split(\"-\", 1)[1]\n        kubepods_match = kubepods_regexp.match(directory)\n        if kubepods_match:\n            pod_id = kubepods_match.group(1)  # if first part of kubepods_regexp matched\n            if not pod_id:\n                pod_id = kubepods_match.group(3)  # if second part of kubepods_regexp matched\n                if pod_id:\n                    pod_id = pod_id.replace(\"_\", \"-\")\n            return {\"container\": {\"id\": container_id}, \"kubernetes\": {\"pod\": {\"uid\": pod_id}}}\n        elif container_id_regexp.match(container_id):\n            return {\"container\": {\"id\": container_id}}\n", "path": "elasticapm/utils/cgroup.py"}]}