automation: drop support for Python 2.7 in Linux environment

We stop installing Python 2.7 via pyenv. We stop installing the system
Python 2 packages. We delete support for running tests on Python 2.7.

Differential Revision: https://phab.mercurial-scm.org/D12262

contrib/automation/hgautomation/aws.py

@@ -919,17 +919,12 b' def ensure_linux_dev_ami(c: AWSConnectio'
         'SecurityGroupIds': [c.security_groups['linux-dev-1'].id],
     }
 
-    requirements2_path = (
-        pathlib.Path(__file__).parent.parent / 'linux-requirements-py2.txt'
-    )
     requirements3_path = (
         pathlib.Path(__file__).parent.parent / 'linux-requirements-py3.txt'
     )
     requirements35_path = (
         pathlib.Path(__file__).parent.parent / 'linux-requirements-py3.5.txt'
     )
-    with requirements2_path.open('r', encoding='utf-8') as fh:
-        requirements2 = fh.read()
     with requirements3_path.open('r', encoding='utf-8') as fh:
         requirements3 = fh.read()
     with requirements35_path.open('r', encoding='utf-8') as fh:
@@ -941,7 +936,6 b' def ensure_linux_dev_ami(c: AWSConnectio'
         {
             'instance_config': config,
             'bootstrap_script': BOOTSTRAP_DEBIAN,
-            'requirements_py2': requirements2,
             'requirements_py3': requirements3,
             'requirements_py35': requirements35,
         }
@@ -977,10 +971,6 b' def ensure_linux_dev_ami(c: AWSConnectio'
                 fh.write(BOOTSTRAP_DEBIAN)
                 fh.chmod(0o0700)
 
-            with sftp.open('%s/requirements-py2.txt' % home, 'wb') as fh:
-                fh.write(requirements2)
-                fh.chmod(0o0700)
-
             with sftp.open('%s/requirements-py3.txt' % home, 'wb') as fh:
                 fh.write(requirements3)
                 fh.chmod(0o0700)

contrib/automation/hgautomation/cli.py

@@ -469,9 +469,7 b' def get_parser():'
         '--python-version',
         help='Python version to use',
         choices={
-            'system2',
             'system3',
-            '2.7',
             '3.5',
             '3.6',
             '3.7',

contrib/automation/hgautomation/linux.py

@@ -25,7 +25,6 b' DISTROS = {'
 }
 
 INSTALL_PYTHONS = r'''
-PYENV2_VERSIONS="2.7.17 pypy2.7-7.2.0"
 PYENV3_VERSIONS="3.5.10 3.6.13 3.7.10 3.8.10 3.9.5 pypy3.5-7.0.0 pypy3.6-7.3.3 pypy3.7-7.3.3"
 
 git clone https://github.com/pyenv/pyenv.git /hgdev/pyenv
@@ -46,13 +45,6 b' VIRTUALENV_TARBALL=virtualenv-16.7.5.tar'
 wget -O ${VIRTUALENV_TARBALL} --progress dot:mega https://files.pythonhosted.org/packages/66/f0/6867af06d2e2f511e4e1d7094ff663acdebc4f15d4a0cb0fed1007395124/${VIRTUALENV_TARBALL}
 echo "${VIRTUALENV_SHA256} ${VIRTUALENV_TARBALL}" | sha256sum --check -
 
-for v in ${PYENV2_VERSIONS}; do
-    pyenv install -v ${v}
-    ${PYENV_ROOT}/versions/${v}/bin/python get-pip.py
-    ${PYENV_ROOT}/versions/${v}/bin/pip install ${VIRTUALENV_TARBALL}
-    ${PYENV_ROOT}/versions/${v}/bin/pip install -r /hgdev/requirements-py2.txt
-done
-
 for v in ${PYENV3_VERSIONS}; do
     pyenv install -v ${v}
     ${PYENV_ROOT}/versions/${v}/bin/python get-pip.py
@@ -72,7 +64,7 b' for v in ${PYENV3_VERSIONS}; do'
     ${PYENV_ROOT}/versions/${v}/bin/pip install -r /hgdev/${REQUIREMENTS}
 done
 
-pyenv global ${PYENV2_VERSIONS} ${PYENV3_VERSIONS} system
+pyenv global ${PYENV3_VERSIONS} system
 '''.lstrip().replace(
     '\r\n', '\n'
 )
@@ -274,17 +266,8 b' PACKAGES="\\'
     netbase \
     ntfs-3g \
     nvme-cli \
-    pyflakes \
     pyflakes3 \
-    pylint \
     pylint3 \
-    python-all-dev \
-    python-dev \
-    python-docutils \
-    python-fuzzywuzzy \
-    python-pygments \
-    python-subversion \
-    python-vcr \
     python3-boto3 \
     python3-dev \
     python3-docutils \
@@ -595,9 +578,7 b' def run_tests(ssh_client, python_version'
 
     print('running tests')
 
-    if python_version == 'system2':
-        python = '/usr/bin/python2'
-    elif python_version == 'system3':
+    if python_version == 'system3':
         python = '/usr/bin/python3'
     elif python_version.startswith('pypy'):
         python = '/hgdev/pyenv/shims/%s' % python_version