github.com_openSUSE_osc/osc/conf.py

# Copyright (C) 2006-2009 Novell Inc.  All rights reserved.
# This program is free software; it may be used, copied, modified
# and distributed under the terms of the GNU General Public Licence,
# either version 2, or version 3 (at your option).


"""Read osc configuration and store it in a dictionary

This module reads and parses oscrc. The resulting configuration is stored
for later usage in a dictionary named 'config'.
The oscrc is kept mode 0600, so that it is not publically readable.
This gives no real security for storing passwords.
If in doubt, use your favourite keyring.
Password is stored on ~/.config/osc/oscrc as bz2 compressed and base64 encoded, so that is fairly
large and not to be recognized or remembered easily by an occasional spectator.

If information is missing, it asks the user questions.

After reading the config, urllib2 is initialized.

The configuration dictionary could look like this:

{'apisrv': 'https://api.opensuse.org/',
 'user': 'joe',
 'api_host_options': {'api.opensuse.org': {'user': 'joe', 'pass': 'secret'},
                      'apitest.opensuse.org': {'user': 'joe', 'pass': 'secret',
                                               'http_headers':(('Host','api.suse.de'),
                                                               ('User','faye'))},
                      'foo.opensuse.org': {'user': 'foo', 'pass': 'foo'}},
 'build-cmd': '/usr/bin/build',
 'build-root': '/abuild/oscbuild-%(repo)s-%(arch)s',
 'packagecachedir': '/var/cache/osbuild',
 'su-wrapper': 'sudo',
 }

"""


import errno
import getpass
import os
import re
import sys
from io import StringIO
from urllib.parse import urlsplit

from . import credentials
from . import OscConfigParser
from . import oscerr
from .util.helper import raw_input


GENERIC_KEYRING = False

try:
    import keyring
    GENERIC_KEYRING = True
except:
    pass


def _get_processors():
    """
    get number of processors (online) based on
    SC_NPROCESSORS_ONLN (returns 1 if config name/os.sysconf does not exist).
    """
    try:
        return os.sysconf('SC_NPROCESSORS_ONLN')
    except (AttributeError, ValueError):
        return 1


def _identify_osccookiejar():
    if os.path.isfile(os.path.join(os.path.expanduser("~"), '.osc_cookiejar')):
        # For backwards compatibility, use the old location if it exists
        return '~/.osc_cookiejar'

    if os.getenv('XDG_STATE_HOME', '') != '':
        osc_state_dir = os.path.join(os.getenv('XDG_STATE_HOME'), 'osc')
    else:
        osc_state_dir = os.path.join(os.path.expanduser("~"), '.local', 'state', 'osc')

    return os.path.join(osc_state_dir, 'cookiejar')


DEFAULTS = {'apiurl': 'https://api.opensuse.org',
            'user': None,
            'pass': None,
            'passx': None,
            'sshkey': None,
            'packagecachedir': '/var/tmp/osbuild-packagecache',
            'su-wrapper': 'sudo',

            # build type settings
            'build-cmd': '/usr/bin/build',
            'build-type': '',                   # may be empty for chroot, kvm or xen
            'build-root': '/var/tmp/build-root/%(repo)s-%(arch)s',
            'build-uid': '',                    # use the default provided by build
            'build-device': '',                 # required for VM builds
            'build-memory': '0',                # required for VM builds
            'build-shell-after-fail': '0',      # optional for VM builds
            'build-swap': '',                   # optional for VM builds
            'build-vmdisk-rootsize': '0',       # optional for VM builds
            'build-vmdisk-swapsize': '0',       # optional for VM builds
            'build-vmdisk-filesystem': '',      # optional for VM builds
            'build-vm-user': '',                # optional for VM builds
            'build-kernel': '',                 # optional for VM builds
            'build-initrd': '',                 # optional for VM builds
            'download-assets-cmd': '/usr/lib/build/download_assets',  # optional for scm/git based builds

            'build-jobs': str(_get_processors()),
            'builtin_signature_check': '1',     # by default use builtin check for verify pkgs
            'icecream': '0',
            'ccache': '0',
            'sccache': '0',
            'sccache_uri': '',

            'buildlog_strip_time': '0',  # strips the build time from the build log

            'debug': '0',
            'http_debug': '0',
            'http_full_debug': '0',
            'http_retries': '3',
            'verbose': '0',
            'no_preinstallimage': '0',
            'traceback': '0',
            'post_mortem': '0',
            'use_keyring': '0',
            'cookiejar': _identify_osccookiejar(),
            # fallback for osc build option --no-verify
            'no_verify': '0',

            # Disable hdrmd5 checks of downloaded and cached packages in `osc build`
            # Recommended value: 0
            #
            # OBS builds the noarch packages once per binary arch.
            # Such noarch packages are supposed to be nearly identical across all build arches,
            # any discrepancy in the payload and dependencies is considered a packaging bug.
            # But to guarantee that the local builds work identically to builds in OBS,
            # using the arch-specific copy of the noarch package is required.
            # Unfortunatelly only one of the noarch packages gets distributed
            # and can be downloaded from a local mirror.
            # All other noarch packages are available through the OBS API only.
            # Since there is currently no information about hdrmd5 checksums of published noarch packages,
            # we download them, verify hdrmd5 and re-download the package from OBS API on mismatch.
            #
            # The same can also happen for architecture depend packages when someone is messing around
            # with the source history or the release number handling in a way that it is not increasing.
            #
            # If you want to save some bandwidth and don't care about the exact rebuilds
            # you can turn this option on to disable hdrmd5 checks completely.
            'disable_hdrmd5_check': '0',

            # enable project tracking by default
            'do_package_tracking': '1',
            # default for osc build
            'extra-pkgs': '',
            # default repository
            'build_repository': 'openSUSE_Factory',
            # default project for branch or bco
            'getpac_default_project': 'openSUSE:Factory',
            # alternate filesystem layout: have multiple subdirs, where colons were.
            'checkout_no_colon': '0',
            # project separator
            'project_separator': ':',
            # change filesystem layout: avoid checkout from within a proj or package dir.
            'checkout_rooted': '0',
            # local files to ignore with status, addremove, ....
            'exclude_glob': '.osc CVS .svn .* _linkerror *~ #*# *.orig *.bak *.changes.vctmp.*',
            # whether to print Web UI links to directly insert in browser (where possible)
            'print_web_links': '0',
            # limit the age of requests shown with 'osc req list'.
            # this is a default only, can be overridden by 'osc req list -D NNN'
            # Use 0 for unlimted.
            'request_list_days': 0,
            # check for unversioned/removed files before commit
            'check_filelist': '1',
            # check for pending requests after executing an action (e.g. checkout, update, commit)
            'check_for_request_on_action': '1',
            # what to do with the source package if the submitrequest has been accepted
            'submitrequest_on_accept_action': '',
            'request_show_interactive': '0',
            'request_show_source_buildstatus': '0',
            # if a review is accepted in interactive mode and a group
            # was specified the review will be accepted for this group
            'review_inherit_group': '0',
            'submitrequest_accepted_template': '',
            'submitrequest_declined_template': '',
            'linkcontrol': '0',
            'include_request_from_project': '1',
            'local_service_run': '1',
            "exclude_files": "",
            "include_files": "",

            # Maintenance defaults to OBS instance defaults
            'maintained_attribute': 'OBS:Maintained',
            'maintenance_attribute': 'OBS:MaintenanceProject',
            'maintained_update_project_attribute': 'OBS:UpdateProject',
            'show_download_progress': '0',
            # path to the vc script
            'vc-cmd': '/usr/lib/build/vc',

            # heuristic to speedup Package.status
            'status_mtime_heuristic': '0'
            }

# some distros like Debian rename and move build to obs-build
if not os.path.isfile('/usr/bin/build') and os.path.isfile('/usr/bin/obs-build'):
    DEFAULTS['build-cmd'] = '/usr/bin/obs-build'
if not os.path.isfile('/usr/lib/build/vc') and os.path.isfile('/usr/lib/obs-build/vc'):
    DEFAULTS['vc-cmd'] = '/usr/lib/obs-build/vc'

api_host_options = ['user', 'pass', 'passx', 'aliases', 'http_headers', 'realname', 'email', 'sslcertck', 'cafile', 'capath', 'trusted_prj',
                    'downloadurl', 'sshkey', 'disable_hdrmd5_check']


# _integer_opts and _boolean_opts specify option types for both global options as well as api_host_options
_integer_opts = ("build-jobs", "build-memory", "build-vmdisk-rootsize", "build-vmdisk-swapsize", "http_retries", "icecream", "request_list_days")

_boolean_opts = (
    'debug', 'do_package_tracking', 'http_debug', 'post_mortem', 'traceback', 'check_filelist',
    'checkout_no_colon', 'checkout_rooted', 'check_for_request_on_action', 'linkcontrol', 'show_download_progress', 'request_show_interactive',
    'request_show_source_buildstatus', 'review_inherit_group', 'use_keyring', 'no_verify', 'disable_hdrmd5_check', 'builtin_signature_check',
    'http_full_debug', 'include_request_from_project', 'local_service_run', 'buildlog_strip_time', 'no_preinstallimage',
    'status_mtime_heuristic', 'print_web_links', 'ccache', 'sccache', 'build-shell-after-fail', 'allow_http', 'sslcertck', )


def apply_option_types(config, conffile=""):
    """
    Return a copy of `config` dictionary with values converted to their expected types
    according to the enumerated option types (_boolean_opts, _integer_opts).
    """
    config = config.copy()

    cp = OscConfigParser.OscConfigParser(config)
    cp.add_section("general")

    typed_opts = ((_boolean_opts, cp.getboolean, bool), (_integer_opts, cp.getint, int))
    for opts, meth, typ in typed_opts:
        for opt in opts:
            if opt not in config:
                continue
            if isinstance(config[opt], typ):
                continue
            try:
                config[opt] = meth('general', opt)
            except ValueError as e:
                msg = 'cannot parse \'%s\' setting: %s' % (opt, str(e))
                raise oscerr.ConfigError(msg, conffile)

    return config


# being global to this module, this dict can be accessed from outside
# it will hold the parsed configuration
config = DEFAULTS.copy()
config = apply_option_types(config)


new_conf_template = """
[general]

# URL to access API server, e.g. %(apiurl)s
# you also need a section [%(apiurl)s] with the credentials
apiurl = %(apiurl)s

# Downloaded packages are cached here. Must be writable by you.
#packagecachedir = %(packagecachedir)s

# Wrapper to call build as root (sudo, su -, ...)
#su-wrapper = %(su-wrapper)s
# set it empty to run build script as user (works only with KVM atm):
#su-wrapper =

# rootdir to setup the chroot environment
# can contain %%(repo)s, %%(arch)s, %%(project)s, %%(package)s and %%(apihost)s (apihost is the hostname
# extracted from currently used apiurl) for replacement, e.g.
# /srv/oscbuild/%%(repo)s-%%(arch)s or
# /srv/oscbuild/%%(repo)s-%%(arch)s-%%(project)s-%%(package)s
#build-root = %(build-root)s

# compile with N jobs (default: "getconf _NPROCESSORS_ONLN")
#build-jobs = N

# build-type to use - values can be (depending on the capabilities of the 'build' script)
# empty    -  chroot build
# kvm      -  kvm VM build  (needs build-device, build-swap, build-memory)
# xen      -  xen VM build  (needs build-device, build-swap, build-memory)
#   experimental:
#     qemu -  qemu VM build
#     lxc  -  lxc build
#build-type =

# Execute always a shell prompt on build failure inside of the build environment
#build-shell-after-fail = 1

# build-device is the disk-image file to use as root for VM builds
# e.g. /var/tmp/FILE.root
#build-device = /var/tmp/FILE.root

# build-swap is the disk-image to use as swap for VM builds
# e.g. /var/tmp/FILE.swap
#build-swap = /var/tmp/FILE.swap

# build-kernel is the boot kernel used for VM builds
#build-kernel = /boot/vmlinuz

# build-initrd is the boot initrd used for VM builds
#build-initrd = /boot/initrd

# build-memory is the amount of memory used in the VM
# value in MB - e.g. 512
#build-memory = 512

# build-vmdisk-rootsize is the size of the disk-image used as root in a VM build
# values in MB - e.g. 4096
#build-vmdisk-rootsize = 4096

# build-vmdisk-swapsize is the size of the disk-image used as swap in a VM build
# values in MB - e.g. 1024
#build-vmdisk-swapsize = 1024

# build-vmdisk-filesystem is the file system type of the disk-image used in a VM build
# values are ext3(default) ext4 xfs reiserfs btrfs
#build-vmdisk-filesystem = ext4

# Numeric uid:gid to assign to the "abuild" user in the build-root
# or "caller" to use the current users uid:gid
# This is convenient when sharing the buildroot with ordinary userids
# on the host.
# This should not be 0
# build-uid =

# strip leading build time information from the build log
# buildlog_strip_time = 1

# Enable ccache in build roots.
# ccache = 1

# Enable sccache in build roots. Conflicts with ccache.
# Equivalent to sccache_uri = file:///var/tmp/osbuild-sccache-{pkgname}.tar
# sccache = 1

# Optional URI for sccache storage. Maybe a file://, redis:// or other URI supported
# by the configured sccache install. This uri MAY take {pkgname} as a special parameter
# which will be replaced with the name of the package to be built.
# sccache_uri = file:///var/tmp/osbuild-sccache-{pkgname}.tar.lzop
# sccache_uri = file:///var/tmp/osbuild-sccache-{pkgname}.tar
# sccache_uri = redis://127.0.0.1:6379

# extra packages to install when building packages locally (osc build)
# this corresponds to osc build's -x option and can be overridden with that
# -x '' can also be given on the command line to override this setting, or
# you can have an empty setting here. This global setting may leads to
# dependency problems when the base distro is not providing the package.
# => using server side definition via cli_debug_packages substitute rule is
#    recommended therefore.
#extra-pkgs =

# build platform is used if the platform argument is omitted to osc build
#build_repository = %(build_repository)s

# default project for getpac or bco
#getpac_default_project = %(getpac_default_project)s

# alternate filesystem layout: have multiple subdirs, where colons were.
#checkout_no_colon = %(checkout_no_colon)s

# instead of colons, use the specified as separator
#project_separator = %(project_separator)s

# change filesystem layout: avoid checkout within a project or package dir.
#checkout_rooted = %(checkout_rooted)s

# local files to ignore with status, addremove, ....
#exclude_glob = %(exclude_glob)s

# limit the age of requests shown with 'osc req list'.
# this is a default only, can be overridden by 'osc req list -D NNN'
# Use 0 for unlimted.
#request_list_days = %(request_list_days)s

# show info useful for debugging
#debug = 1

# show HTTP traffic useful for debugging
#http_debug = 1

# number of retries on HTTP transfer
#http_retries = 3

# Skip signature verification of packages used for build.
#no_verify = 1

# jump into the debugger in case of errors
#post_mortem = 1

# print call traces in case of errors
#traceback = 1

# check for unversioned/removed files before commit
#check_filelist = 1

# check for pending requests after executing an action (e.g. checkout, update, commit)
#check_for_request_on_action = 1

# what to do with the source package if the submitrequest has been accepted. If
# nothing is specified the API default is used
#submitrequest_on_accept_action = cleanup|update|noupdate

# template for an accepted submitrequest
#submitrequest_accepted_template = Hi %%(who)s,\\n
# thanks for working on:\\t%%(tgt_project)s/%%(tgt_package)s.
# SR %%(reqid)s has been accepted.\\n\\nYour maintainers

# template for a declined submitrequest
#submitrequest_declined_template = Hi %%(who)s,\\n
# sorry your SR %%(reqid)s (request type: %%(type)s) for
# %%(tgt_project)s/%%(tgt_package)s has been declined because...

#review requests interactively (default: off)
#request_show_review = 1

# if a review is accepted in interactive mode and a group
# was specified the review will be accepted for this group (default: off)
#review_inherit_group = 1

[%(apiurl)s]
# set aliases for this apiurl
# aliases = foo, bar
# real name used in .changes, unless the one from osc meta prj <user> will be used
# realname =
# email used in .changes, unless the one from osc meta prj <user> will be used
# email =
# additional headers to pass to a request, e.g. for special authentication
#http_headers = Host: foofoobar,
#       User: mumblegack
# Plain text password
#pass =
"""


account_not_configured_text = """
Your user account / password are not configured yet.
You will be asked for them below, and they will be stored in
%s for future use.
"""

config_incomplete_text = """

Your configuration file %s is not complete.
Make sure that it has a [general] section.
(You can copy&paste the below. Some commented defaults are shown.)

"""

config_missing_apiurl_text = """
The apiurl \'%s\' does not exist in the config file. Please enter
your credentials for this apiurl.
"""


def parse_apisrv_url(scheme, apisrv):
    if apisrv.startswith('http://') or apisrv.startswith('https://'):
        url = apisrv
    elif scheme is not None:
        url = scheme + apisrv
    else:
        url = "https://" + apisrv
    scheme, url, path = urlsplit(url)[0:3]
    return scheme, url, path.rstrip('/')


def urljoin(scheme, apisrv, path=''):
    return '://'.join([scheme, apisrv]) + path


def is_known_apiurl(url):
    """returns ``True`` if url is a known apiurl"""
    apiurl = urljoin(*parse_apisrv_url(None, url))
    return apiurl in config['api_host_options']


def extract_known_apiurl(url):
    """
    Return longest prefix of given url that is known apiurl,
    None if there is no known apiurl that is prefix of given url.
    """
    scheme, host, path = parse_apisrv_url(None, url)
    p = path.split('/')
    while p:
        apiurl = urljoin(scheme, host, '/'.join(p))
        if apiurl in config['api_host_options']:
            return apiurl
        p.pop()
    return None


def get_apiurl_api_host_options(apiurl):
    """
    Returns all apihost specific options for the given apiurl, ``None`` if
    no such specific options exist.
    """
    # FIXME: in A Better World (tm) there was a config object which
    # knows this instead of having to extract it from a url where it
    # had been mingled into before.  But this works fine for now.

    apiurl = urljoin(*parse_apisrv_url(None, apiurl))
    if is_known_apiurl(apiurl):
        return config['api_host_options'][apiurl]
    raise oscerr.ConfigMissingApiurl('missing credentials for apiurl: \'%s\'' % apiurl,
                                     '', apiurl)


def get_apiurl_usr(apiurl):
    """
    returns the user for this host - if this host does not exist in the
    internal api_host_options the default user is returned.
    """
    # FIXME: maybe there should be defaults not just for the user but
    # for all apihost specific options.  The ConfigParser class
    # actually even does this but for some reason we don't use it
    # (yet?).

    try:
        return get_apiurl_api_host_options(apiurl)['user']
    except KeyError:
        print('no specific section found in config file for host of [\'%s\'] - using default user: \'%s\''
              % (apiurl, config['user']), file=sys.stderr)
        return config['user']


def get_configParser(conffile=None, force_read=False):
    """
    Returns an ConfigParser() object. After its first invocation the
    ConfigParser object is stored in a method attribute and this attribute
    is returned unless you pass force_read=True.
    """
    if not conffile:
        conffile = identify_conf()

    conffile = os.path.expanduser(conffile)
    if 'conffile' not in get_configParser.__dict__:
        get_configParser.conffile = conffile
    if force_read or 'cp' not in get_configParser.__dict__ or conffile != get_configParser.conffile:
        get_configParser.cp = OscConfigParser.OscConfigParser(DEFAULTS)
        get_configParser.cp.read(conffile)
        get_configParser.conffile = conffile
    return get_configParser.cp


def write_config(fname, cp):
    """write new configfile in a safe way"""
    if os.path.exists(fname) and not os.path.isfile(fname):
        # only write to a regular file
        return

    # config file is behind a symlink
    # resolve the symlink and continue writing the config as usual
    if os.path.islink(fname):
        fname = os.readlink(fname)

    # create directories to the config file (if they don't exist already)
    fdir = os.path.dirname(fname)
    if fdir:
        try:
            os.makedirs(fdir, mode=0o700)
        except OSError as e:
            if e.errno != errno.EEXIST:
                raise

    with open(fname + '.new', 'w') as f:
        cp.write(f, comments=True)
    try:
        os.rename(fname + '.new', fname)
        os.chmod(fname, 0o600)
    except:
        if os.path.exists(fname + '.new'):
            os.unlink(fname + '.new')
        raise


def config_set_option(section, opt, val=None, delete=False, update=True, creds_mgr_descr=None, **kwargs):
    """
    Sets a config option. If val is not specified the current/default value is
    returned. If val is specified, opt is set to val and the new value is returned.
    If an option was modified get_config is called with ``**kwargs`` unless update is set
    to ``False`` (``override_conffile`` defaults to ``config['conffile']``).
    If val is not specified and delete is ``True`` then the option is removed from the
    config/reset to the default value.
    """
    cp = get_configParser(config['conffile'])
    # don't allow "internal" options
    general_opts = [i for i in DEFAULTS.keys() if i not in ['user', 'pass', 'passx']]
    if section != 'general':
        section = config['apiurl_aliases'].get(section, section)
        scheme, host, path = \
            parse_apisrv_url(config.get('scheme', 'https'), section)
        section = urljoin(scheme, host, path)

    sections = {}
    for url in cp.sections():
        if url == 'general':
            sections[url] = url
        else:
            scheme, host, path = \
                parse_apisrv_url(config.get('scheme', 'https'), url)
            apiurl = urljoin(scheme, host, path)
            sections[apiurl] = url

    section = sections.get(section.rstrip('/'), section)
    if section not in cp.sections():
        raise oscerr.ConfigError('unknown section \'%s\'' % section, config['conffile'])
    if section == 'general' and opt not in general_opts or \
       section != 'general' and opt not in api_host_options:
        raise oscerr.ConfigError('unknown config option \'%s\'' % opt, config['conffile'])

    if not val and not delete and opt == 'pass' and creds_mgr_descr is not None:
        # change password store
        creds_mgr = _get_credentials_manager(section, cp)
        user = _extract_user_compat(cp, section, creds_mgr)
        val = creds_mgr.get_password(section, user, defer=False)

    run = False
    if val:
        if opt == 'pass':
            creds_mgr = _get_credentials_manager(section, cp)
            user = _extract_user_compat(cp, section, creds_mgr)
            old_pw = creds_mgr.get_password(section, user, defer=False)
            try:
                creds_mgr.delete_password(section, user)
                if creds_mgr_descr:
                    creds_mgr_new = creds_mgr_descr.create(cp)
                else:
                    creds_mgr_new = creds_mgr
                creds_mgr_new.set_password(section, user, val)
                write_config(config['conffile'], cp)
                opt = credentials.AbstractCredentialsManager.config_entry
                old_pw = None
            finally:
                if old_pw is not None:
                    creds_mgr.set_password(section, user, old_pw)
                    # not nice, but needed if the Credentials Manager will change
                    # something in cp
                    write_config(config['conffile'], cp)
        else:
            cp.set(section, opt, val)
            write_config(config['conffile'], cp)
        run = True
    elif delete and (cp.has_option(section, opt) or opt == 'pass'):
        if opt == 'pass':
            creds_mgr = _get_credentials_manager(section, cp)
            user = _extract_user_compat(cp, section, creds_mgr)
            creds_mgr.delete_password(section, user)
        else:
            cp.remove_option(section, opt)
        write_config(config['conffile'], cp)
        run = True
    if run and update:
        kw = {
            'override_conffile': config['conffile'],
            'override_no_keyring': config['use_keyring'],
        }
        kw.update(kwargs)
        get_config(**kw)
    if cp.has_option(section, opt):
        return (opt, cp.get(section, opt, raw=True))
    return (opt, None)


def _extract_user_compat(cp, section, creds_mgr):
    """
    This extracts the user either from the ConfigParser or
    the creds_mgr. Only needed for deprecated Gnome Keyring
    """
    user = cp.get(section, 'user')
    if user is None and hasattr(creds_mgr, 'get_user'):
        user = creds_mgr.get_user(section)
    return user


def write_initial_config(conffile, entries, custom_template='', creds_mgr_descriptor=None):
    """
    write osc's intial configuration file. entries is a dict which contains values
    for the config file (e.g. { 'user' : 'username', 'pass' : 'password' } ).
    custom_template is an optional configuration template.
    """
    conf_template = custom_template or new_conf_template
    config = DEFAULTS.copy()
    config.update(entries)
    sio = StringIO(conf_template.strip() % config)
    cp = OscConfigParser.OscConfigParser(DEFAULTS)
    cp.readfp(sio)
    cp.set(config['apiurl'], 'user', config['user'])
    if creds_mgr_descriptor:
        creds_mgr = creds_mgr_descriptor.create(cp)
    else:
        creds_mgr = _get_credentials_manager(config['apiurl'], cp)
    creds_mgr.set_password(config['apiurl'], config['user'], config['pass'])
    write_config(conffile, cp)


def add_section(filename, url, user, passwd, creds_mgr_descriptor=None, allow_http=None):
    """
    Add a section to config file for new api url.
    """
    global config
    cp = get_configParser(filename)
    try:
        cp.add_section(url)
    except OscConfigParser.configparser.DuplicateSectionError:
        # Section might have existed, but was empty
        pass
    cp.set(url, 'user', user)
    if creds_mgr_descriptor:
        creds_mgr = creds_mgr_descriptor.create(cp)
    else:
        creds_mgr = _get_credentials_manager(url, cp)
    creds_mgr.set_password(url, user, passwd)
    if allow_http:
        cp.set(url, 'allow_http', "1")
    write_config(filename, cp)


def _get_credentials_manager(url, cp):
    if cp.has_option(url, credentials.AbstractCredentialsManager.config_entry):
        creds_mgr = credentials.create_credentials_manager(url, cp)
        if creds_mgr is None:
            msg = 'Unable to instantiate creds mgr (section: %s)' % url
            conffile = get_configParser.conffile
            raise oscerr.ConfigMissingCredentialsError(msg, conffile, url)
        return creds_mgr
    if config['use_keyring'] and GENERIC_KEYRING:
        return credentials.get_keyring_credentials_manager(cp)
    elif cp.get(url, 'passx') is not None:
        return credentials.ObfuscatedConfigFileCredentialsManager(cp, None)
    return credentials.PlaintextConfigFileCredentialsManager(cp, None)


class APIHostOptionsEntry(dict):
    def __getitem__(self, key, *args, **kwargs):
        value = super().__getitem__(key, *args, **kwargs)
        if key == 'pass' and callable(value):
            print('Warning: use of a deprecated credentials manager API.',
                  file=sys.stderr)
            value = value()
        return value


def get_config(override_conffile=None,
               override_apiurl=None,
               override_debug=None,
               override_http_debug=None,
               override_http_full_debug=None,
               override_traceback=None,
               override_post_mortem=None,
               override_no_keyring=None,
               override_verbose=None,
               overrides=None
               ):
    """do the actual work (see module documentation)"""
    global config

    if not override_conffile:
        conffile = identify_conf()
    else:
        conffile = override_conffile

    conffile = os.path.expanduser(conffile)
    if not os.path.exists(conffile):
        raise oscerr.NoConfigfile(conffile,
                                  account_not_configured_text % conffile)

    # okay, we made sure that oscrc exists

    # make sure it is not world readable, it may contain a password.
    conffile_stat = os.stat(conffile)
    if conffile_stat.st_mode != 0o600:
        try:
            os.chmod(conffile, 0o600)
        except OSError as e:
            if e.errno in (errno.EROFS, errno.EPERM):
                print(f"Warning: Configuration file '{conffile}' may have insecure file permissions.")
            else:
                raise e

    cp = get_configParser(conffile)

    if not cp.has_section('general'):
        # FIXME: it might be sufficient to just assume defaults?
        msg = config_incomplete_text % conffile
        msg += new_conf_template % DEFAULTS
        raise oscerr.ConfigError(msg, conffile)

    config = dict(cp.items('general', raw=1))

    # if the overrides trigger an exception, the 'post_mortem' option
    # must be set to the appropriate type otherwise the non-empty string gets evaluated as True
    config = apply_option_types(config, conffile)

    overrides = overrides or {}
    for key, value in overrides.items():
        if key not in config:
            raise oscerr.ConfigError(f"Unknown config option '{key}'", "<command-line>")
        config[key] = value

    config['conffile'] = conffile

    config = apply_option_types(config, conffile)

    config['packagecachedir'] = os.path.expanduser(config['packagecachedir'])
    config['exclude_glob'] = config['exclude_glob'].split()

    re_clist = re.compile('[, ]+')
    config['extra-pkgs'] = [i.strip() for i in re_clist.split(config['extra-pkgs'].strip()) if i]
    config["exclude_files"] = [i.strip() for i in re_clist.split(config["exclude_files"].strip()) if i]
    config["include_files"] = [i.strip() for i in re_clist.split(config["include_files"].strip()) if i]

    # collect the usernames, passwords and additional options for each api host
    api_host_options = {}

    # Regexp to split extra http headers into a dictionary
    # the text to be matched looks essentially looks this:
    # "Attribute1: value1, Attribute2: value2, ..."
    # there may be arbitray leading and intermitting whitespace.
    # the following regexp does _not_ support quoted commas within the value.
    http_header_regexp = re.compile(r"\s*(.*?)\s*:\s*(.*?)\s*(?:,\s*|\Z)")

    # override values which we were called with
    # This needs to be done before processing API sections as it might be already used there
    if override_no_keyring:
        config['use_keyring'] = False

    aliases = {}
    for url in [x for x in cp.sections() if x != 'general']:
        # backward compatiblity
        scheme, host, path = parse_apisrv_url(config.get('scheme', 'https'), url)
        apiurl = urljoin(scheme, host, path)
        creds_mgr = _get_credentials_manager(url, cp)
        # if the deprecated gnomekeyring is used we should use the apiurl instead of url
        # (that's what the old code did), but this makes things more complex
        # (also, it is very unlikely that url and apiurl differ)
        user = _extract_user_compat(cp, url, creds_mgr)
        if user is None:
            raise oscerr.ConfigMissingCredentialsError('No user found in section %s' % url, conffile, url)
        password = creds_mgr.get_password(url, user, defer=True, apiurl=apiurl)
        if password is None:
            raise oscerr.ConfigMissingCredentialsError('No password found in section %s' % url, conffile, url)

        if cp.has_option(url, 'http_headers'):
            http_headers = cp.get(url, 'http_headers')
            http_headers = http_header_regexp.findall(http_headers)
        else:
            http_headers = []
        if cp.has_option(url, 'aliases'):
            for i in cp.get(url, 'aliases').split(','):
                key = i.strip()
                if key == '':
                    continue
                if key in aliases:
                    msg = 'duplicate alias entry: \'%s\' is already used for another apiurl' % key
                    raise oscerr.ConfigError(msg, conffile)
                aliases[key] = url

        entry = {'user': user,
                 'pass': password,
                 'http_headers': http_headers}
        api_host_options[apiurl] = APIHostOptionsEntry(entry)

        optional = (
            'realname', 'email', 'sslcertck', 'cafile', 'capath', 'sshkey', 'allow_http',
            credentials.AbstractCredentialsManager.config_entry,
        )
        for key in optional:
            if not cp.has_option(url, key):
                continue
            if key in _boolean_opts:
                api_host_options[apiurl][key] = cp.getboolean(url, key)
            elif key in _integer_opts:
                api_host_options[apiurl][key] = cp.getint(url, key)
            else:
                api_host_options[apiurl][key] = cp.get(url, key)

        if cp.has_option(url, 'build-root', proper=True):
            api_host_options[apiurl]['build-root'] = cp.get(url, 'build-root', raw=True)

        if 'sslcertck' not in api_host_options[apiurl]:
            api_host_options[apiurl]['sslcertck'] = True

        if 'cafile' not in api_host_options[apiurl]:
            api_host_options[apiurl]['cafile'] = None

        if 'capath' not in api_host_options[apiurl]:
            api_host_options[apiurl]['capath'] = None

        if 'allow_http' not in api_host_options[apiurl]:
            api_host_options[apiurl]['allow_http'] = False

        if cp.has_option(url, 'trusted_prj'):
            api_host_options[apiurl]['trusted_prj'] = cp.get(url, 'trusted_prj').split(' ')
        else:
            api_host_options[apiurl]['trusted_prj'] = []

        # This option is experimental and may be removed at any time in the future!
        # This allows overriding the download url for an OBS instance to specify a closer mirror
        # or proxy system, which can greatly improve download performance, latency and more.
        # For example, this can use https://github.com/Firstyear/opensuse-proxy-cache in a local
        # geo to improve performance.
        if cp.has_option(url, 'downloadurl'):
            api_host_options[apiurl]['downloadurl'] = cp.get(url, 'downloadurl')
        else:
            api_host_options[apiurl]['downloadurl'] = None

        if api_host_options[apiurl]['sshkey'] is None:
            api_host_options[apiurl]['sshkey'] = config['sshkey']

        api_host_options[apiurl]["disable_hdrmd5_check"] = config["disable_hdrmd5_check"]
        if cp.has_option(url, "disable_hdrmd5_check"):
            api_host_options[apiurl]["disable_hdrmd5_check"] = cp.getboolean(url, "disable_hdrmd5_check")

    # add the auth data we collected to the config dict
    config['api_host_options'] = api_host_options
    config['apiurl_aliases'] = aliases

    apiurl = aliases.get(config['apiurl'], config['apiurl'])
    config['apiurl'] = urljoin(*parse_apisrv_url(None, apiurl))
    # backward compatibility
    if 'apisrv' in config:
        apisrv = config['apisrv'].lstrip('http://')
        apisrv = apisrv.lstrip('https://')
        scheme = config.get('scheme', 'https')
        config['apiurl'] = urljoin(scheme, apisrv)
    if 'apisrc' in config or 'scheme' in config:
        print('Warning: Use of the \'scheme\' or \'apisrv\' in oscrc is deprecated!\n'
              'Warning: See README for migration details.', file=sys.stderr)
    if 'build_platform' in config:
        print('Warning: Use of \'build_platform\' config option is deprecated! (use \'build_repository\' instead)', file=sys.stderr)
        config['build_repository'] = config['build_platform']

    config['verbose'] = bool(int(config['verbose']))
    # override values which we were called with
    if override_verbose is not None:
        config['verbose'] = bool(override_verbose)

    config['debug'] = bool(int(config['debug']))
    if override_debug is not None:
        config['debug'] = bool(override_debug)

    if override_http_debug:
        config['http_debug'] = override_http_debug
    if override_http_full_debug:
        config['http_debug'] = override_http_full_debug or config['http_debug']
        config['http_full_debug'] = override_http_full_debug
    if override_traceback:
        config['traceback'] = override_traceback
    if override_post_mortem:
        config['post_mortem'] = override_post_mortem
    if override_apiurl:
        apiurl = aliases.get(override_apiurl, override_apiurl)
        # check if apiurl is a valid url
        config['apiurl'] = urljoin(*parse_apisrv_url(None, apiurl))

    # XXX unless config['user'] goes away (and is replaced with a handy function, or
    # config becomes an object, even better), set the global 'user' here as well,
    # provided that there _are_ credentials for the chosen apiurl:
    try:
        config['user'] = get_apiurl_usr(config['apiurl'])
    except oscerr.ConfigMissingApiurl as e:
        e.msg = config_missing_apiurl_text % config['apiurl']
        e.file = conffile
        raise e

    scheme = urlsplit(apiurl)[0]
    if scheme == "http" and not api_host_options[apiurl]['allow_http']:
        msg = "The apiurl '{apiurl}' uses HTTP protocol without any encryption.\n"
        msg += "All communication incl. sending your password IS NOT ENCRYPTED!\n"
        msg += "Add 'allow_http=1' to the [{apiurl}] config file section to mute this message.\n"
        print(msg.format(apiurl=apiurl), file=sys.stderr)

    # enable connection debugging after all config options are set
    from .connection import enable_http_debug
    enable_http_debug(config)


def identify_conf():
    # needed for compat reasons(users may have their oscrc still in ~
    if 'OSC_CONFIG' in os.environ:
        return os.environ.get('OSC_CONFIG')
    if os.path.exists(os.path.expanduser('~/.oscrc')):
        return '~/.oscrc'

    if os.environ.get('XDG_CONFIG_HOME', '') != '':
        conffile = os.environ.get('XDG_CONFIG_HOME') + '/osc/oscrc'
    else:
        conffile = '~/.config/osc/oscrc'

    return conffile


def interactive_config_setup(conffile, apiurl, initial=True):
    if not apiurl:
        apiurl = DEFAULTS["apiurl"]

    scheme = urlsplit(apiurl)[0]
    http = scheme == "http"
    if http:
        msg = "The apiurl '{apiurl}' uses HTTP protocol without any encryption.\n"
        msg += "All communication incl. sending your password WILL NOT BE ENCRYPTED!\n"
        msg += "Do you really want to continue with no encryption?\n"
        print(msg.format(apiurl=apiurl), file=sys.stderr)
        yes = raw_input("Type 'YES' to continue: ")
        if yes != "YES":
            raise oscerr.UserAbort()
        print()

    apiurl_no_scheme = urlsplit(apiurl)[1]
    user_prompt = f"Username [{apiurl_no_scheme}]: "
    user = raw_input(user_prompt)
    pass_prompt = f"Password [{user}@{apiurl_no_scheme}]: "
    passwd = getpass.getpass(pass_prompt)
    creds_mgr_descr = select_credentials_manager_descr()
    if initial:
        config = {'user': user, 'pass': passwd}
        if apiurl:
            config['apiurl'] = apiurl
        if http:
            config['allow_http'] = 1
        write_initial_config(conffile, config, creds_mgr_descriptor=creds_mgr_descr)
    else:
        add_section(conffile, apiurl, user, passwd, creds_mgr_descriptor=creds_mgr_descr, allow_http=http)


def select_credentials_manager_descr():
    if not credentials.has_keyring_support():
        print('To use keyrings please install python%d-keyring.' % sys.version_info.major)
    creds_mgr_descriptors = credentials.get_credentials_manager_descriptors()

    rows = []
    for i, creds_mgr_descr in enumerate(creds_mgr_descriptors, 1):
        rows += [str(i), creds_mgr_descr.name(), creds_mgr_descr.description()]

    from .core import build_table
    headline = ('NUM', 'NAME', 'DESCRIPTION')
    table = build_table(len(headline), rows, headline)
    print()
    for row in table:
        print(row)

    i = raw_input('Select credentials manager [default=1]: ')
    if not i:
        i = "1"
    if not i.isdigit():
        sys.exit('Invalid selection')
    i = int(i) - 1
    if i < 0 or i >= len(creds_mgr_descriptors):
        sys.exit('Invalid selection')
    return creds_mgr_descriptors[i]

# vim: sw=4 et