diskimage-builder/diskimage_builder/disk_image_create.py
Dmitry Tantsur 1e1e36df64 Do not fail in a venv when activate_this.py is not found
The standard Python venv module does not have this script, so currently
DIB unconditionally fails. While a real fix will be provided in
https://review.opendev.org/#/c/704478/ this change at least allows
users to try work around the problem.

Change-Id: I45b79d4d283f2b3ea909612e652672dcb6092488
2020-06-09 12:53:21 +10:00

85 lines
3.1 KiB
Python

# Copyright 2016 Ian Wienand (iwienand@redhat.com)
#
# Licensed 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.
from __future__ import print_function
import os
import os.path
import runpy
import sys
import diskimage_builder.paths
# borrowed from pip:locations.py
def running_under_virtualenv():
"""Return True if we're running inside a virtualenv, False otherwise."""
if hasattr(sys, 'real_prefix'):
return True
elif sys.prefix != getattr(sys, "base_prefix", sys.prefix):
return True
return False
def activate_venv():
if running_under_virtualenv():
activate_this = os.path.join(sys.prefix, "bin", "activate_this.py")
try:
globs = runpy.run_path(activate_this, globals())
globals().update(globs)
del globs
# TODO(dtantsur): replace with FileNotFoundError when Python 2 is no
# longer supported.
except OSError:
print("WARNING: A virtual environment was detected, but the "
"activate_this.py script was not found. You may need to set "
"PATH manually", file=sys.stderr)
def main():
# If we are called directly from a venv install
# (/path/venv/bin/disk-image-create) then nothing has added the
# virtualenv bin/ dir to $PATH. the exec'd script below will be
# unable to find call other dib tools like dib-run-parts.
#
# One solution is to say that you should only ever run
# disk-image-create in a shell that has already sourced
# bin/activate.sh (all this really does is add /path/venv/bin to
# $PATH). That's not a great interface as resulting errors will
# be very non-obvious.
#
# We can detect if we are running in a virtualenv and use
# virtualenv's "activate_this.py" script to activate it ourselves
# before we call the script. This ensures we have the path setting
activate_venv()
environ = os.environ
# pre-seed some paths for the shell script
environ['_LIB'] = diskimage_builder.paths.get_path('lib')
# export the path to the current python
if not os.environ.get('DIB_PYTHON_EXEC'):
os.environ['DIB_PYTHON_EXEC'] = sys.executable
# we have to handle being called as "disk-image-create" or
# "ramdisk-image-create". ramdisk-iamge-create is just a symlink
# to disk-image-create
# XXX: we could simplify things by removing the symlink, and
# just setting IS_RAMDISK in environ here depending on sys.argv[1]
script = "%s/%s" % (diskimage_builder.paths.get_path('lib'),
os.path.basename(sys.argv[0]))
os.execve("/bin/bash", ['bash', script] + sys.argv[1:], environ)