keycloak.py

import requests
import logging
import cachetools.func
import os
import json
import re
from lofar.sas.tmss.tmss.exceptions import TMSSException
from lofar.sas.tmss.tmss.tmssapp import models
logger = logging.Logger(__name__)

KEYCLOAK_TOKEN_URL = os.environ.get('KEYCLOAK_TOKEN_URL', 'https://sdc-dev.astron.nl/auth/realms/master/protocol/openid-connect/token')
KEYCLOAK_ADMIN_USER = os.environ.get('KEYCLOAK_ADMIN_USER', 'secret')
KEYCLOAK_ADMIN_PASSWORD = os.environ.get('KEYCLOAK_ADMIN_PASSWORD', 'secret')
KEYCLOAK_API_BASE_URL = os.environ.get('KEYCLOAK_API_BASE_URL', 'https://sdc-dev.astron.nl/auth/admin/realms/master')


class KeycloakAdminAPISession(requests.Session):

    @cachetools.func.ttl_cache(ttl=30)
    def get_token(self):
        data = {'username': KEYCLOAK_ADMIN_USER, 'password': KEYCLOAK_ADMIN_PASSWORD, 'grant_type': 'password',
                'client_id': 'admin-cli'}
        response = self.post(url=KEYCLOAK_TOKEN_URL, data=data)  # , headers={'Accept': 'text/plain'})
        if response.status_code == 200:
            response_dict = json.loads(response.content.decode('utf-8'))
            token = response_dict['access_token']
            logger.info('Obtained Keycloak API token')
            return token
        else:
            raise TMSSException('Keycloak admin API token could not be obtained: %s' % response.text)

    def get(self, *args, **kwargs):
        token = self.get_token()
        headers = kwargs.pop('headers', {})
        headers["Authorization"] = "Bearer %s" % token
        response = super().get(*args, headers=headers, **kwargs)
        if response.status_code == 200:
            return json.loads(response.content.decode('utf-8'))
        else:
            raise TMSSException('Keycloak admin API query failed: %s' % response.text)


def get_users_by_role_in_project(role, project):
    """
    returns the list of users that have the specified role in the specified project
    """
    project_persons = get_project_persons()
    if project in project_persons:
        return project_persons[project][role]
    else:
        []


@cachetools.func.ttl_cache(ttl=600)
def get_project_persons():
    """
    returns a mapping of projects names to a dict that contains the users that
    have a particular role in that project.
    """
    project_persons_map = {}
    with KeycloakAdminAPISession() as ksession:
        groups = ksession.get(url='%s/groups/' % KEYCLOAK_API_BASE_URL)
        for group in groups:
            if group['name'] == 'Project':
                projects = group['subGroups']
        for project in projects:
            project_detail = ksession.get(url='%s/groups/%s/' % (KEYCLOAK_API_BASE_URL, project['id']))
            attributes = project_detail.get('attributes', {})

            legacy_role_keys = {'pi': 'lofarProjectPI',
                                'friend_of_project': 'lofarProjectFriend',
                                'contact': 'lofarProjectContactauthor'}

            for project_role in models.ProjectRole.Choices:
                # get role attribute from project:
                role = project_role.value
                users = attributes.get(role, [])
                # fall back to legacy-style attribute:
                if not users and role in legacy_role_keys:
                    users = attributes.get(legacy_role_keys[role], [])

                # convert user list (LDAP DNs) to something we can use in TMSS (email)
                user_map = get_user_mapping()
                mapped_users = [user_map[user] for user in users if user in user_map]  # email list of referenced users
                unmappable_users = [user for user in users if user not in user_map]  # list of references for which no account was found
                for unmappable_user in unmappable_users:
                    # Note: Usually Keycloak should return DN references to user accounts. For PI's, someone had the
                    # great idea to allow to specify a freeform string instead, to refer to people who may or may not
                    # have an account. Even if the person has a user account, there is no way to replicate the exact
                    # string 'representation' Keycloak returns, since the string may contain typos, or info that is not
                    # stored in the user accounts (like titles).
                    # The following unsafe hack tries to determine whether there is a user account that matches the
                    # name given in the string (ignore titles since they are not part of the user account):
                    # unmappable_user_fixed = re.sub('Dr\.', '', unmappable_user)
                    # unmappable_user_fixed = re.sub('Prof\.', '', unmappable_user_fixed)
                    # unmappable_user_fixed = re.sub('ir\.', '', unmappable_user_fixed)
                    # unmappable_user_fixed = re.sub('Ir\.', '', unmappable_user_fixed)
                    # unmappable_user_fixed = re.sub('apl\.', '', unmappable_user_fixed)
                    # unmappable_user_fixed = re.sub(' +', ' ', unmappable_user_fixed)
                    #
                    # if unmappable_user_fixed in user_map:
                    #     mapped_users.append(user_map[unmappable_user_fixed])
                    # else:
                        logger.warning("Could not match Keycloak user reference '%s' to a known user." % unmappable_user)
                        if not unmappable_user.startswith('cn='):
                            logger.warning("LOFAR allowed to reference a person by a freeform string instead of a user account. '%s' seems to be such a legacy reference. This needs to be fixed in the identity management." % unmappable_user)
                project_persons_map.setdefault(project['name'], {})[role] = mapped_users

    return project_persons_map


@cachetools.func.ttl_cache(ttl=600)
def get_user_mapping():
    """
    returns a mapping of both the string ('Project, Tobitha') or LDAP ('cn=to_project,ou=Users,o=lofartest,c=eu')
    representations of users that are returned by Keycloak to a reference that we can use to identify a user
    in TMSS, i.e. email.
    # todo: consider looking up / creating / returning user objects directly (but that generates a ton of lookups and unnecessary users)
    # todo: we need to review that all used references are actually unique, especially Keycloak's reference by string representation does not look safe!
    """
    user_map = {}
    with KeycloakAdminAPISession() as ksession:
        users = ksession.get(url='%s/users/' % KEYCLOAK_API_BASE_URL)
        for user in users:
            if 'attributes' in user:
                for ldap_dn in user['attributes'].get('LDAP_ENTRY_DN', []):
                    user_map[ldap_dn] = user['email']
                for ldap_dn in user['attributes'].get('KEYCLOAK_DN', []):
                    user_map[ldap_dn] = user['email']
            if 'firstName' in user and 'lastName' in user:
                user_map['%s, %s' % (user['lastName'], user['firstName'])] = user['email']

    return user_map