replace ubuntu1710 image by ubuntu1804

templates/tools/dockerfile/test/cxx_ubuntu1710_x64/Dockerfile.template → templates/tools/dockerfile/test/cxx_ubuntu1804_x64/Dockerfile.template

@@ -14,7 +14,7 @@
   # See the License for the specific language governing permissions and
   # limitations under the License.
   
-  FROM ubuntu:17.10
+  FROM ubuntu:18.04
   
   <%include file="../../apt_get_basic.include"/>
   <%include file="../../gcp_api_libraries.include"/>

tools/dockerfile/test/cxx_ubuntu1710_x64/Dockerfile → tools/dockerfile/test/cxx_ubuntu1804_x64/Dockerfile

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-FROM ubuntu:17.10
+FROM ubuntu:18.04
 
 # Install Git and basic packages.
 RUN apt-get update && apt-get install -y \

tools/run_tests/run_tests.py

@@ -516,8 +516,8 @@ class CLanguage(object):
             return ('jessie', self._gcc_make_options(version_suffix='-4.8'))
         elif compiler == 'gcc5.3':
             return ('ubuntu1604', [])
-        elif compiler == 'gcc7.2':
-            return ('ubuntu1710', [])
+        elif compiler == 'gcc7.4':
+            return ('ubuntu1804', [])
         elif compiler == 'gcc_musl':
             return ('alpine', [])
         elif compiler == 'clang3.4':
@@ -1474,7 +1474,7 @@ argp.add_argument(
 argp.add_argument(
     '--compiler',
     choices=[
-        'default', 'gcc4.4', 'gcc4.6', 'gcc4.8', 'gcc4.9', 'gcc5.3', 'gcc7.2',
+        'default', 'gcc4.4', 'gcc4.6', 'gcc4.8', 'gcc4.9', 'gcc5.3', 'gcc7.4',
         'gcc_musl', 'clang3.4', 'clang3.5', 'clang3.6', 'clang3.7', 'clang7.0',
         'python2.7', 'python3.4', 'python3.5', 'python3.6', 'python3.7',
         'python3.8', 'pypy', 'pypy3', 'python_alpine', 'all_the_cpythons',

tools/run_tests/run_tests_matrix.py

@@ -316,7 +316,7 @@ def _create_portability_test_jobs(extra_args=[],
 
     # portability C and C++ on x64
     for compiler in [
-            'gcc4.8', 'gcc5.3', 'gcc7.2', 'gcc_musl', 'clang3.5', 'clang3.6',
+            'gcc4.8', 'gcc5.3', 'gcc7.4', 'gcc_musl', 'clang3.5', 'clang3.6',
             'clang3.7', 'clang7.0'
     ]:
         test_jobs += _generate_jobs(