diskimage-builder/diskimage_builder/disk_image_create.py

69 lines
2.5 KiB
Python
Raw Normal View History

# 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.
import os
import os.path
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")
execfile(activate_this, dict(__file__=activate_this))
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')
# 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)