add experimental CI job to run sanity tests
diff --git a/tools/dockerfile/push_testing_images.sh b/tools/dockerfile/push_testing_images.sh
index f1ee8d5..9dceb29 100755
--- a/tools/dockerfile/push_testing_images.sh
+++ b/tools/dockerfile/push_testing_images.sh
@@ -44,7 +44,7 @@
 
 DOCKERHUB_ORGANIZATION=grpctesting
 
-for DOCKERFILE_DIR in tools/dockerfile/test/fuzzer
+for DOCKERFILE_DIR in tools/dockerfile/test/fuzzer tools/dockerfile/test/sanity
 do
   # Generate image name based on Dockerfile checksum. That works well as long
   # as can count on dockerfiles being written in a way that changing the logical 
diff --git a/tools/internal_ci/linux/grpc_pull_request_sanity.cfg b/tools/internal_ci/linux/grpc_pull_request_sanity.cfg
new file mode 100644
index 0000000..511f2d6
--- /dev/null
+++ b/tools/internal_ci/linux/grpc_pull_request_sanity.cfg
@@ -0,0 +1,39 @@
+# Copyright 2017, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# 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_sanity.sh"
+timeout_mins: 30
+action {
+  define_artifacts {
+    regex: "**/sponge_log.xml"
+  }
+}
diff --git a/tools/internal_ci/linux/grpc_sanity.sh b/tools/internal_ci/linux/grpc_sanity.sh
new file mode 100755
index 0000000..fac25c7
--- /dev/null
+++ b/tools/internal_ci/linux/grpc_sanity.sh
@@ -0,0 +1,40 @@
+#!/bin/bash
+# Copyright 2017, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+set -ex
+
+# change to grpc repo root
+cd $(dirname $0)/../../..
+
+git submodule update --init
+
+# download base docker image from dockerhub
+export DOCKERHUB_ORGANIZATION=grpctesting
+tools/run_tests/run_tests.py -l sanity -c opt -t -x sponge_log.xml --use_docker --report_suite_name sanity_linux_opt