diskimage-builder/diskimage_builder/elements/pip-and-virtualenv/install.d/pip-and-virtualenv-source-install/04-install-pip

#!/bin/bash

if [ ${DIB_DEBUG_TRACE:-0} -gt 0 ]; then
    set -x
fi
set -eu
set -o pipefail

if [[ $DISTRO_NAME =~ (opensuse|fedora|centos|centos7|rhel7) ]]; then

    # Default packages
    _do_py3=0
    _extra_repo=''
    case "$DISTRO_NAME" in
        centos*|rhel7)
            # note python2-pip in epel
            _extra_repo="--enablerepo=epel"
            packages="python-virtualenv python2-pip python-setuptools"
            ;;
        fedora)
            _do_py3=1
            packages="python2-virtualenv python2-pip python2-setuptools"
            packages+=" python3-virtualenv python3-pip python3-setuptools"
            ;;
        opensuse)
            case "$DIB_RELEASE" in
                42*)
                    packages="python-virtualenv python-pip python-setuptools"
                    ;;
                tumbleweed)
                    # XXX: python3?
                    packages="python2-virtualenv python2-pip python2-setuptools"
                    ;;
            esac
    esac

    # force things to happen so our assumptions hold
    pip_args="-U --force-reinstall"

    # GENERAL WARNING : mixing packaged python libraries with
    # pip-installed versions always creates issues.  Upstream
    # openstack-infra uses this a lot (especially devstack) but be
    # warned: here be dragons :)

    # Firstly we want to install the system packages.  Otherwise later
    # on somebody does a "yum install python-virtualenv" and goes and
    # overwrites the pip installed version with the packaged version,
    # leading to all sorts of weird version issues.
    if [[ $DISTRO_NAME = opensuse ]]; then
        zypper -n install $packages
    else
        ${YUM:-yum} ${_extra_repo} install -y $packages
    fi

    # pip10 (unlike earlier versions) will not uninstall distutils
    # installed packages (note this is only a subset of packages that
    # don't use setuptools for various reasons).  We give it a little
    # help by clearing out the files from the packages we are about to
    # re-install so pip doesn't think anything is installed.  See:
    # https://github.com/pypa/pip/issues/4805
    for pkg in $packages; do
        rpm -ql $pkg | xargs rm -rf
    done

    # install the latest python2 pip; this overwrites packaged pip
    python /tmp/get-pip.py ${pip_args}

    # Install latest setuptools; there is a slight chicken-egg issue in
    # that pip requires setuptools for some operations like building a
    # wheel.  But this simple install should be fine.
    pip install ${pip_args} setuptools

    if [[ $_do_py3 -eq 1 ]]; then
        # Repeat above for python3

        # python2 on fedora always installs into /usr/bin.  Move pip2
        # binary out, as we want "pip" in the final image to be
        # python2 for historical reasons.
        mv /usr/bin/pip /usr/bin/pip2

        # You would think that installing python3 bits first, then
        # python2 would work -- alas get-pip.py doesn't seem to leave
        # python3 alone:
        #  https://github.com/pypa/pip/issues/4435
        python3 /tmp/get-pip.py ${pip_args}
        pip3 install ${pip_args} setuptools

        # on < 27, this installed pip3 to /usr/bin/pip.  On >=27 it's
        # /usr/local/bin/pip.  reclaim /usr/bin/pip back to pip2 and
        # remove the /usr/local/bin/pip (i.e. python3 version) if it
        # exists, so that "pip" calls pip2 always.  if we want pip3 we
        # call it explicitly.
        ln -sf /usr/bin/pip2 /usr/bin/pip
        rm -f /usr/local/bin/pip
    fi

    # now install latest virtualenv.  it vendors stuff it needs so
    # doesn't have issues with other system packages.

    # python[2|3]-virtualenv package has installed versioned scripts
    # (/usr/bin/virtualenv-[2|3]) but upstream does not!  (see [2]).
    # For consistency, reinstall so we're just left with python2's
    # version.  Note this is a rather moot point, the usual way we get
    # a python3 environment is to call "virtualenv -p python3 foo" and
    # that works to create a python3 virtualenv, even if using
    # python2's version.  Thus we probably don't *really* need to
    # "pip3 install virtualenv".  What we don't want is "virtualenv
    # foo" creating a python3 virtualenv by default, because that
    # confuses a lot of legacy code.
    #
    #[2] http://pkgs.fedoraproject.org/cgit/rpms/python-virtualenv.git/tree/python-virtualenv.spec#n116)
    pip install ${pip_args} virtualenv
    mv /usr/bin/virtualenv /usr/bin/virtualenv2
    if [[ $_do_py3 -eq 1 ]]; then
        pip3 install ${pip_args} virtualenv
    fi

    # Reclaim virtualenv to virtualenv2; similar to above, on fedora
    # >27 the pip3 version has gone into /usr/local/bin; remove it so
    # only /usr/bin/virtualenv exists
    ln -sf /usr/bin/virtualenv2 /usr/bin/virtualenv
    rm -f /usr/local/bin/virtualenv

    # at this point, we should have the latest
    # pip/setuptools/virtualenv packages for python2 & 3, and
    # "/usr/bin/pip" and "/usr/bin/virtualenv" should be python2
    # versions.

    if [[ $DISTRO_NAME = opensuse ]]; then
        for pkg in virtualenv pip setuptools; do
            cat - >> /etc/zypp/locks <<EOF
type: package
match_type: glob
case_sensitive: on
solvable_name: python-$pkg
EOF
        done
    else
        # Add this to exclude so that we don't install a later package
        # over it if it updates.  Note that fedora-minimal, bootstrapped
        # via yum, can have an old yum.conf around, so look for dnf first.
        if [[ -f /etc/dnf/dnf.conf ]]; then
            conf=/etc/dnf/dnf.conf
        elif [[ -f /etc/yum.conf ]]; then
            conf=/etc/yum.conf
        else
            die "No conf to modify?"
        fi
        echo "exclude=$packages" >> ${conf}
    fi
elif [[ $DISTRO_NAME = gentoo ]]; then
    packages="dev-python/pip dev-python/virtualenv"
    emerge -U $packages
else
    # pre-install packages so dependencies are there.  We will
    # overwrite with latest below.
    packages="python-pip python3-pip python-virtualenv"

    # Unfortunately older ubuntu (trusty) doesn't have a
    # python3-virtualenv package -- it seems it wasn't ready at the
    # time and you had to use "python -m venv".  Since then virtualenv
    # has gained 3.4 support so the pip install below will work
    if [[ ${DIB_PYTHON_VERSION} == 3 ]]; then
        packages+=" python3-virtualenv"
    fi

    apt-get -y install $packages

    # force things to happen so our assumptions hold
    pip_args="-U --force-reinstall"

    # These install into /usr/local/bin so override any packages, even
    # if installed later.

    python3 /tmp/get-pip.py $pip_args
    python2 /tmp/get-pip.py $pip_args

    pip3 install $pip_args virtualenv
    pip install $pip_args virtualenv
fi