Docker files for xds example server and client for C++. (#37778)

We need to create userguide examples for Xds not involving Observability and currently only the csm observability example has a docker image.

Closes #37778

COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/37778 from kannanjgithub:docker_xds_example_cpp bc91c8d5da
PiperOrigin-RevId: 678362755

examples/cpp/xds/Dockerfile.client

@@ -0,0 +1,37 @@
+# Copyright 2023 The 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 python:3.9-slim-bookworm
+
+RUN apt-get update -y && apt-get upgrade -y && apt-get install -y build-essential clang curl
+
+WORKDIR /workdir
+
+RUN ln -s /usr/bin/python3 /usr/bin/python
+RUN mkdir /artifacts
+
+COPY . .
+RUN tools/bazel build //examples/cpp/xds:xds_greeter_client
+RUN cp -rL /workdir/bazel-bin/examples/cpp/xds/xds_greeter_client /artifacts/
+
+FROM python:3.9-slim-bookworm
+
+RUN apt-get update \
+    && apt-get -y upgrade \
+    && apt-get -y autoremove \
+    && apt-get install -y curl
+
+COPY --from=0 /artifacts ./
+
+ENTRYPOINT ["/xds_greeter_client"]

examples/cpp/xds/Dockerfile.server

@@ -0,0 +1,37 @@
+# Copyright 2023 The 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 python:3.9-slim-bookworm
+
+RUN apt-get update -y && apt-get upgrade -y && apt-get install -y build-essential clang curl
+
+WORKDIR /workdir
+
+RUN ln -s /usr/bin/python3 /usr/bin/python
+RUN mkdir /artifacts
+
+COPY . .
+RUN tools/bazel build //examples/cpp/xds:xds_greeter_server
+RUN cp -rL /workdir/bazel-bin/examples/cpp/xds/xds_greeter_server /artifacts/
+
+FROM python:3.9-slim-bookworm
+
+RUN apt-get update \
+    && apt-get -y upgrade \
+    && apt-get -y autoremove \
+    && apt-get install -y curl
+
+COPY --from=0 /artifacts ./
+
+ENTRYPOINT ["/xds_greeter_server"]

examples/cpp/xds/README.md

@@ -35,3 +35,24 @@ $ export GRPC_XDS_BOOTSTRAP=/path/to/bootstrap.json
 $ tools/bazel run examples/cpp/xds:greeter_client
 ```
 
+## Building Docker
+
+From the gRPC workspace folder:
+
+Client:
+```
+docker build -f examples/cpp/xds/Dockerfile.client examples/cpp/xds
+```
+Server:
+```
+docker build -f examples/cpp/xds/Dockerfile.server examples/cpp/xds
+```
+
+To push to a registry, add a tag to the image either by adding a `-t` flag to `docker build` command above or run:
+
+```
+docker image tag ${sha from build command above} ${tag}
+```
+
+And then push the tagged image using `docker push`
+