Adding a second Dockerfile supporting C++20 for cmake C++20 tests

ci/Dockerfile

@@ -5,13 +5,17 @@ WORKDIR /setup-ci
 ADD setup_ci_environment.sh /setup-ci
 ADD setup_cmake.sh /setup-ci
 ADD install_gcc48.sh /setup-ci
+ADD install_gcc10.sh /setup-ci
 ADD install_bazelisk.sh /setup-ci
 ADD install_protobuf.sh /setup-ci
 ADD install_format_tools.sh /setup-ci
 
+
 RUN /setup-ci/setup_ci_environment.sh \
   && /setup-ci/setup_cmake.sh \
   && /setup-ci/install_gcc48.sh \
+  && /setup-ci/install_gcc10.sh \
   && /setup-ci/install_bazelisk.sh \
   && /setup-ci/install_protobuf.sh \
   && /setup-ci/install_format_tools.sh
+

ci/README.md

@@ -17,4 +17,7 @@ CI tests can be run on docker by invoking the script `./ci/run_docker.sh ./ci/do
 * `code.coverage`: build cmake targets and run tests. Then upload coverage report to [codecov.io](https://codecov.io/).
 
 Additionally, `./ci/run_docker.sh` can be invoked with no arguments to get a docker shell where tests
-can be run manually.
+can be run manually, except for `cmake.c++20.test`.
+
+Note that `cmake.c++20.test` can only run in a Ubuntu version 20+ container, as earlier versions of Ubuntu do not support C++20 or g++-10.
+To run said test, you must run it in the specified Ubuntu 20.04 container by invoking `./ci/run_docker.sh ./ci/do_ci.sh cmake.c++20.test`.

ci/do_ci.sh

@@ -21,6 +21,7 @@ if [[ "$1" == "cmake.test" ]]; then
   make test
   exit 0
 elif [[ "$1" == "cmake.c++20.test" ]]; then
+  echo "${BUILD_DIR}"
   cd "${BUILD_DIR}"
   rm -rf *
   cmake -DCMAKE_BUILD_TYPE=Debug  \

ci/install_gcc10.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+set -e
+apt-get -y install software-properties-common
+add-apt-repository -y ppa:ubuntu-toolchain-r/test
+apt-get -y update
+apt install -y gcc-10
+apt install -y g++-10

ci/run_docker.sh

@@ -2,13 +2,13 @@
 
 set -e
 
-BUILD_IMAGE=opentelemetry-cpp-build
+BUILD_IMAGE=opentelemetry-cpp-build-test
+
 docker image inspect "$BUILD_IMAGE" &> /dev/null || {
   docker build -t "$BUILD_IMAGE" ci
-}
-
+  }
 if [[ $# -ge 1 ]]; then
   docker run -v "$PWD":/src -w /src -it "$BUILD_IMAGE" "$@"
 else
   docker run -v "$PWD":/src -w /src --privileged -it "$BUILD_IMAGE" /bin/bash -l
-fi
+fi