Add build_abseil-cpp_at_head

tools/internal_ci/linux/grpc_build_abseil-cpp_at_head.cfg

@@ -0,0 +1,31 @@
+# Copyright 2020 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.
+
+# Config file for the internal CI (in protobuf text format)
+
+# Location of the continuous shell script in repository.
+build_file: "grpc/tools/internal_ci/linux/grpc_build_submodule_at_head.sh"
+timeout_mins: 240
+action {
+  define_artifacts {
+    regex: "**/*sponge_log.*"
+    regex: "github/grpc/reports/**"
+  }
+}
+
+# Tiny hack: misusing an already whitelisted env var to pass submodule name
+env_vars {
+  key: "RUN_TESTS_FLAGS"
+  value: "abseil-cpp"
+}

tools/internal_ci/linux/grpc_build_submodule_at_head.sh

@@ -40,6 +40,11 @@ echo "2) some change that was just merged in the submodule head has caused the f
 echo ""
 echo "submodule '${SUBMODULE_NAME}' is at commit: $(cd third_party/${SUBMODULE_NAME}; git rev-parse --verify HEAD)"
 
+if [ "${SUBMODULE_NAME}" == "abseil-cpp" ]
+then
+  src/abseil-cpp/preprocessed_builds.yaml.gen.py
+fi
+
 tools/buildgen/generate_projects.sh
 
 if [ "${SUBMODULE_NAME}" == "protobuf" ]