Changes to allow build (in docker run) to run as the user, not root, so BUILD…

Changes to allow build (in docker run) to run as the user, not root, so BUILD directory is easily removable.

contrib/docker/Makefile

@@ -2,7 +2,9 @@
 # are added.
 
 DIR = $(realpath ../..)
-VOLUME = -v ${DIR}:/root/ngraph-cpp-test
+# Use /tmp/ngraph-cpp-test, because we run as the user (and not root)
+# /root/ngraph-cpp-test is not used, because /root is not accessible to user
+VOLUME = -v ${DIR}:/tmp/ngraph-cpp-test
 GIT_COMMIT = $(shell git rev-parse HEAD)
 BUILD_VERSION = ${GIT_COMMIT}_${PYTHON_VERSION}
 BUILD_DIR = ${DIR}/contrib/docker/.build-${BUILD_VERSION}
@@ -46,7 +48,12 @@ build_ngraph_cpp_cpu: expand_dockerfile_templates
 build_all: build_ngraph_cpp_cpu
 
 check_cpu: build_ngraph_cpp_cpu
-	docker run --rm ${DOCKER_RUN_ENV} ${VOLUME} -t ngraph_cpp_cpu:${BUILD_VERSION} sh -c "mkdir BUILD ; cd BUILD ; cmake .. ; make check"
+	# Make BUILD directory as user
+	mkdir -p ${DIR}/BUILD
+	chmod ug+rwx ${DIR}/BUILD
+	# Need to use /tmp/ngraph-cpp-test/BUILD, because running as user
+	# Can't use /root/ngraph-cpp-test/BUILD, because /root not accessible to user
+	docker run --rm --user ${CALLER_UID}:${CALLER_GID} ${DOCKER_RUN_ENV} ${VOLUME} -w /tmp/ngraph-cpp-test/BUILD -t ngraph_cpp_cpu:${BUILD_VERSION} sh -c "cmake .. ; make check"
 	# update the files to be owned by the calling user instead of root, to avoid docker mount problems with file ownership
 	docker run --rm ${VOLUME} \
 	--env MY_UID=${CALLER_UID} \