fbcode_builder: drop support for Ubuntu 14.04 and Debian 8.6

Summary:
folly, and therefore most of our other open source projects, no longer support
gcc-4.9.  Drop Ubuntu 14.04 and Debian 8.6 from our CI platforms list, since
the these images only support gcc 4.9.

We should ideally add support for Ubuntu 18.04 soon, but I'll leave that for a
later diff.  Removing the older platforms is somewhat higher priority for now
to get our Travis CI builds green again.

Reviewed By: snarkmaster

Differential Revision: D9258797

fbshipit-source-id: 3cab47a6c51b2dbe63214034240f844c85963c3d

.travis.yml

@@ -36,12 +36,6 @@ cache:
 #   https://github.com/travis-ci/travis-ci/issues/5142
 matrix:
   include:
-    - env: ['os_image=ubuntu:14.04', gcc_version=4.9]
-      services: [docker]
-    # Unlike 14.04, this Debian Stable has 4.9 as the system compiler, so
-    # there is no risk of 4.8/4.9 ABI incompatibilities.
-    - env: ['os_image=debian:8.6', gcc_version=4.9]
-      services: [docker]
     - env: ['os_image=ubuntu:16.04', gcc_version=5]
       services: [docker]
 

build/fbcode_builder/fbcode_builder.py

@@ -216,14 +216,6 @@ class FBCodeBuilder(object):
         ]
         gcc_version = self.option('gcc_version')
 
-        # We need some extra packages to be able to install GCC 4.9 on 14.04.
-        if self.option('os_image') == 'ubuntu:14.04' and gcc_version == '4.9':
-            actions.append(self.run(ShellQuoted(
-                'apt-get install -yq software-properties-common && '
-                'add-apt-repository ppa:ubuntu-toolchain-r/test && '
-                'apt-get update'
-            )))
-
         # Make the selected GCC the default before building anything
         actions.extend([
             self.run(ShellQuoted('apt-get install -yq {c} {cpp}').format(
@@ -240,24 +232,6 @@ class FBCodeBuilder(object):
             self.run(ShellQuoted('update-alternatives --config gcc')),
         ])
 
-        # Ubuntu 14.04 comes with a CMake version that is too old for mstch.
-        if self.option('os_image') == 'ubuntu:14.04':
-            actions.append(self.run(ShellQuoted(
-                'apt-get install -yq software-properties-common && '
-                'add-apt-repository ppa:george-edison55/cmake-3.x && '
-                'apt-get update && '
-                'apt-get upgrade -yq cmake'
-            )))
-
-        # Debian 8.6 comes with a CMake version that is too old for folly.
-        if self.option('os_image') == 'debian:8.6':
-            actions.append(self.run(ShellQuoted(
-                'echo deb http://ftp.debian.org/debian jessie-backports main '
-                '>> /etc/apt/sources.list.d/jessie-backports.list && '
-                'apt-get update && '
-                'apt-get -yq -t jessie-backports install cmake'
-            )))
-
         actions.extend(self.debian_ccache_setup_steps())
 
         return self.step('Install packages for Debian-based OS', actions)

build/fbcode_builder/make_docker_context.py

@@ -43,7 +43,7 @@ def make_docker_context(
         opts = {}
 
     valid_versions = (
-        ('ubuntu:14.04', '4.9'), ('ubuntu:16.04', '5'), ('debian:8.6', '4.9')
+        ('ubuntu:16.04', '5'),
     )
 
     def add_args(parser):
@@ -69,14 +69,14 @@ def make_docker_context(
         )
         parser.add_argument(
             '--os-image', metavar='IMG', choices=zip(*valid_versions)[0],
-            default=opts.get('os_image', 'debian:8.6'),
+            default=opts.get('os_image', valid_versions[0][0]),
             help='Docker OS image -- be sure to use only ones you trust (See '
                 'README.docker). Choices: %(choices)s. Default: %(default)s.',
         )
         parser.add_argument(
             '--gcc-version', metavar='VER',
             choices=set(zip(*valid_versions)[1]),
-            default=opts.get('gcc_version', '4.9'),
+            default=opts.get('gcc_version', valid_versions[0][1]),
             help='Choices: %(choices)s. Default: %(default)s.',
         )
         parser.add_argument(