[Deps ] Upgrade oldest supported clang version to clang-7 (#37572)

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Closes #37572

COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/37572 from yijiem:upgrade-clang-7 03f8cdc54e
PiperOrigin-RevId: 670692896

templates/tools/dockerfile/test/cxx_clang_7_x64/Dockerfile.template

@@ -0,0 +1,29 @@
+%YAML 1.2
+--- |
+  # Copyright 2021 gRPC authors.
+  #
+  # Licensed under the Apache License, Version 2.0 (the "License");
+  # you may not use this file except in compliance with the License.
+  # You may obtain a copy of the License at
+  #
+  #     http://www.apache.org/licenses/LICENSE-2.0
+  #
+  # Unless required by applicable law or agreed to in writing, software
+  # distributed under the License is distributed on an "AS IS" BASIS,
+  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  # See the License for the specific language governing permissions and
+  # limitations under the License.
+  
+  FROM silkeh/clang:7-buster
+  
+  RUN apt update && apt -y upgrade && apt install -y build-essential curl git time wget zip && apt clean
+  <%include file="../../git_avoid_dubious_ownership_error.include"/>
+  <%include file="../../run_tests_python_deps.include"/>
+  <%include file="../../cxx_test_deps.include"/>
+  <%include file="../../cxx_deps.include"/>
+  <%include file="../../cmake_from_install_script.include"/>
+  <%include file="../../ccache.include"/>
+  <%include file="../../run_tests_addons.include"/>
+  
+  # Define the default command.
+  CMD ["bash"]

tools/dockerfile/test/cxx_clang_7_x64.current_version

@@ -0,0 +1 @@
+us-docker.pkg.dev/grpc-testing/testing-images-public/cxx_clang_7_x64:e921e71a352c09ab68e0068c9c4cd6b5df121e84@sha256:b35f94648ada85aab9110dae0ebca594cd278672d4bbce38312cefa372952cae

tools/dockerfile/test/cxx_clang_7_x64/Dockerfile

@@ -0,0 +1,83 @@
+# Copyright 2021 gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+FROM silkeh/clang:7-buster
+
+RUN apt update && apt -y upgrade && apt install -y build-essential curl git time wget zip && apt clean
+#=================
+# Setup git to access working directory across docker boundary.
+# This avoids the "fatal: detected dubious ownership in repository XYZ"
+# git error.
+
+RUN git config --global --add safe.directory '*'
+RUN git config --global protocol.file.allow always
+
+#====================
+# run_tests.py python dependencies
+
+# Basic python dependencies to be able to run tools/run_tests python scripts
+# These dependencies are not sufficient to build gRPC Python, gRPC Python
+# deps are defined elsewhere (e.g. python_deps.include)
+RUN apt-get update && apt-get install -y \
+  python3 \
+  python3-pip \
+  python3-setuptools \
+  python3-yaml \
+  && apt-get clean
+
+# use pinned version of pip to avoid sudden breakages
+RUN python3 -m pip install --upgrade pip==19.3.1
+
+# TODO(jtattermusch): currently six is needed for tools/run_tests scripts
+# but since our python2 usage is deprecated, we should get rid of it.
+RUN python3 -m pip install six==1.16.0
+
+# Google Cloud Platform API libraries
+# These are needed for uploading test results to BigQuery (e.g. by tools/run_tests scripts)
+RUN python3 -m pip install --upgrade google-auth==1.23.0 google-api-python-client==1.12.8 oauth2client==4.1.0
+
+
+# Some cxx tests depend on the twisted package
+RUN python3 -m pip install twisted
+
+#=================
+# C++ dependencies
+RUN apt-get update && apt-get -y install libc++-dev clang && apt-get clean
+
+#=================
+# Install cmake using the install script.
+RUN curl -sSL -o cmake-linux.sh https://github.com/Kitware/CMake/releases/download/v3.16.1/cmake-3.16.1-Linux-x86_64.sh \
+    && sh cmake-linux.sh -- --skip-license --prefix=/usr \
+    && rm cmake-linux.sh
+
+#=================
+# Install ccache
+
+# Install ccache from source since ccache 3.x packaged with most linux distributions
+# does not support Redis backend for caching.
+RUN curl -sSL -o ccache.tar.gz https://github.com/ccache/ccache/releases/download/v4.7.5/ccache-4.7.5.tar.gz \
+    && tar -zxf ccache.tar.gz \
+    && cd ccache-4.7.5 \
+    && mkdir build && cd build \
+    && cmake -DCMAKE_BUILD_TYPE=Release -DZSTD_FROM_INTERNET=ON -DHIREDIS_FROM_INTERNET=ON .. \
+    && make -j4 && make install \
+    && cd ../.. \
+    && rm -rf ccache-4.7.5 ccache.tar.gz
+
+
+RUN mkdir /var/local/jenkins
+
+
+# Define the default command.
+CMD ["bash"]

tools/run_tests/run_tests.py

@@ -604,8 +604,8 @@ class CLanguage(object):
             )
         elif compiler == "gcc_musl":
             return ("alpine", [])
-        elif compiler == "clang6":
-            return ("clang_6", self._clang_cmake_configure_extra_args())
+        elif compiler == "clang7":
+            return ("clang_7", self._clang_cmake_configure_extra_args())
         elif compiler == "clang18":
             return ("clang_18", self._clang_cmake_configure_extra_args())
         else:
@@ -1672,7 +1672,7 @@ argp.add_argument(
         "gcc12",
         "gcc12_openssl309",
         "gcc_musl",
-        "clang6",
+        "clang7",
         "clang18",
         # TODO: Automatically populate from supported version
         "python3.7",

tools/run_tests/run_tests_matrix.py

@@ -361,7 +361,7 @@ def _create_portability_test_jobs(
         "gcc12",
         "gcc12_openssl309",
         "gcc_musl",
-        "clang6",
+        "clang7",
         "clang18",
     ]:
         test_jobs += _generate_jobs(