HADOOP-15195. With SELinux enabled, directories mounted with start-bu…

…ild-env.sh may not be accessible. Contributed by Grigori Rybkine

hadoop-common-project/hadoop-common/src/test/scripts/start-build-env.bats

@@ -0,0 +1,102 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You 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.
+
+load hadoop-functions_test_helper
+
+# Mock docker command
+docker () {
+  if [ "$1" = "-v" ]; then
+    shift
+    echo Docker version ${DCKR_MOCK_VER:?}
+  elif [ "$1" = run ]; then
+    shift
+    until [ $# -eq 0 ]; do
+      if [ "$1" = -v ]; then
+        shift
+        echo "$1"|awk -F':' '{if (NF == 3 && $3 == "z")
+                  printf "Mounted %s with %s option.\n", $1, $3
+                              else if (NF == 2)
+                  printf "Mounted %s without %s option.\n", $1, "z"}'
+      fi
+      shift
+    done
+  fi
+}
+export -f docker
+export DCKR_MOCK_VER
+
+# Mock a SELinux enabled system
+enable_selinux () {
+  mkdir -p "${TMP}/bin"
+  echo true >"${TMP}/bin"/selinuxenabled
+  chmod a+x "${TMP}/bin"/selinuxenabled
+  if [ "${PATH#${TMP}/bin}" = "${PATH}" ]; then
+    PATH="${TMP}/bin":"$PATH"
+  fi
+}
+
+setup_user () {
+  if [ -z "$(printenv USER)" ]; then
+    if [ -z "$USER" ]; then
+      USER=${HOME##*/}
+    fi
+    export USER
+  fi
+}
+
+# Mock stat command as used in start-build-env.sh
+stat () {
+  if [ "$1" = --printf='%C' -a $# -eq 2 ]; then
+    printf 'mock_u:mock_r:mock_t:s0'
+  else
+    command stat "$@"
+  fi
+}
+export -f stat
+
+# Verify that host directories get mounted without z option
+# and INFO messages get printed out
+@test "start-build-env.sh (Docker without z mount option)" {
+  if [ "$(uname -s)" != "Linux" ]; then
+    skip "Not on Linux platform"
+  fi
+  enable_selinux
+  setup_user
+  DCKR_MOCK_VER=1.4
+  run "${BATS_TEST_DIRNAME}/../../../../../start-build-env.sh"
+  [ "$status" -eq 0 ]
+  [[ ${lines[0]} == "INFO: SELinux policy is enforced." ]]
+  [[ ${lines[1]} =~ \
+     "Mounted ".*" may not be accessible to the container." ]]
+  [[ ${lines[2]} == \
+     "INFO: If so, on the host, run the following command:" ]]
+  [[ ${lines[3]} =~ "# chcon -Rt svirt_sandbox_file_t " ]]
+  [[ ${lines[-2]} =~ "Mounted ".*" without z option." ]]
+  [[ ${lines[-1]} =~ "Mounted ".*" without z option." ]]
+}
+
+# Verify that host directories get mounted with z option
+@test "start-build-env.sh (Docker with z mount option)" {
+  if [ "$(uname -s)" != "Linux" ]; then
+    skip "Not on Linux platform"
+  fi
+  enable_selinux
+  setup_user
+  DCKR_MOCK_VER=1.7
+  run "${BATS_TEST_DIRNAME}/../../../../../start-build-env.sh"
+  [ "$status" -eq 0 ]
+  [[ ${lines[-2]} =~ "Mounted ".*" with z option." ]]
+  [[ ${lines[-1]} =~ "Mounted ".*" with z option." ]]
+}

start-build-env.sh

@@ -21,10 +21,36 @@ cd "$(dirname "$0")" # connect to root
 
 docker build -t hadoop-build dev-support/docker
 
-if [ "$(uname -s)" == "Linux" ]; then
+if [ "$(uname -s)" = "Linux" ]; then
   USER_NAME=${SUDO_USER:=$USER}
   USER_ID=$(id -u "${USER_NAME}")
   GROUP_ID=$(id -g "${USER_NAME}")
+  # man docker-run
+  # When using SELinux, mounted directories may not be accessible
+  # to the container. To work around this, with Docker prior to 1.7
+  # one needs to run the "chcon -Rt svirt_sandbox_file_t" command on
+  # the directories. With Docker 1.7 and later the z mount option
+  # does this automatically.
+  if command -v selinuxenabled >/dev/null && selinuxenabled; then
+    DCKR_VER=$(docker -v|awk '$1 == "Docker" && $2 == "version"\
+                         {split($3,ver,".");print ver[1]"."ver[2]}')
+    DCKR_MAJ=${DCKR_VER%.*}
+    DCKR_MIN=${DCKR_VER#*.}
+    if [ "${DCKR_MAJ}" -eq 1 ] && [ "${DCKR_MIN}" -ge 7 ] ||
+        [ "${DCKR_MAJ}" -gt 1 ]; then
+      V_OPTS=:z
+    else
+      for d in "${PWD}" "${HOME}/.m2"; do
+        ctx=$(stat --printf='%C' "$d"|cut -d':' -f3)
+        if [ "$ctx" != svirt_sandbox_file_t ] && [ "$ctx" != container_file_t ]; then
+          printf 'INFO: SELinux policy is enforced.\n'
+          printf '\tMounted %s may not be accessible to the container.\n' "$d"
+          printf 'INFO: If so, on the host, run the following command:\n'
+          printf '\t# chcon -Rt svirt_sandbox_file_t %s\n' "$d"
+        fi
+      done
+    fi
+  fi
 else # boot2docker uid and gid
   USER_NAME=$USER
   USER_ID=1000
@@ -45,8 +71,8 @@ UserSpecificDocker
 # system.  And this also is a significant speedup in subsequent
 # builds because the dependencies are downloaded only once.
 docker run --rm=true -t -i \
-  -v "${PWD}:/home/${USER_NAME}/hadoop" \
+  -v "${PWD}:/home/${USER_NAME}/hadoop${V_OPTS:-}" \
   -w "/home/${USER_NAME}/hadoop" \
-  -v "${HOME}/.m2:/home/${USER_NAME}/.m2" \
+  -v "${HOME}/.m2:/home/${USER_NAME}/.m2${V_OPTS:-}" \
   -u "${USER_NAME}" \
   "hadoop-build-${USER_ID}"