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UAL Patron Groups

Overview

The software is a small, quick Python hack that synchronizes LDAP queries against UA's Enterprise Directory Service ("EDS") into Grouper groups living in UA's central Grouper service. In the original use case, those group memberships then show up as "isMemberOf" attributes in the information returned from a successful Shibboleth authentication; vendors running Shib-aware services can then use the "isMemberOf" information to make authorization and access control decisions.

Note that the general principle behind this project -- exposing the complexity of "who gets access to what" as simple authorization attributes based on group membership -- should hopefully be broadly applicable to other use cases in the future.

Setup

Dev install, build, and testing

We want to avoid polluting our system-level Python environment, so we install a local environment using PyEnv and PyEnv-Virtualenv. For now, this repo supports scripted installation of Pyenv on MacOS, Debian Linux, and Alpine Linux.

This software assumes that we have Python3 and pip3 installed in both development and production environments.

The required python version (as set in the production server) is found in the .python-version file in the root of the project. The python interpreter is only installed locally, and gets automagically used when the user's terminal session enters the project directory. Therefore it is necessary to change directory into the project to later run development PG scripts.

  • Checkout the repo files and change directory into the project root.
  • Install pyenv with ./install_pyenv.sh. This checks for Pyenv, installs if it's not there. It may also ask the user to update their shell profile to use pyenv.
  • Build the virtual environment and add the Patron Groups package with ./build.sh, enter "dev" at the prompt.
  • Copy the .env_dist file to .env, then fill in the passwords with the correct credentials, probably located in Stache.
  • Test run the scripts with ./run_petl_dev.sh. This script does not run the actual sync (--sync).
  • When the development code is ready to be tagged, change the version in src/main/python/src/petal/__init__.py::__version__. This property is referenced as the final package version when installed in production. It should be a SemVer number format.

Production deployment

Production petl.library.arizona.edu will run the Patron Groups scripts daily with a cron job that hits the run_petl_prod.sh script (sync is live).

The production environment is different because it uses a global Python interpreter. Therefore, packages need to be updated using sudo permissions. There is no virtual environment to run the scripts from, and the petal package is "compiled" using the regular Python distribution. For this simple server setup, the user needs to SSH in to petl.library.arizona.edu.

  • Change directory into /usr/local/ual-patron-groups/

  • Run ./build.sh, enter "prod" at the prompt.

  • To test that the build version updated, enter the Python console and enter the following code:

    >>> import petal
    >>> help(petal)

Note: it may be necessary to delete the user cache for the Petal package to install the updated package correctly: $ rm -rf /home/<user>/.cache. Git ssh key credentials will also need to be set correctly, or the package will not update.

Petl script usage

The petl script that serves as the command line wrapper for the petal Python package is located at src/main/python/scripts/petl. Several of the usage parameters are set in run_petl_prod.sh and run_petl_dev.sh, with variables set in the .env file. To run the script by itself, it can be invoked from the project root directory with $ python src/main/python/scripts/petl. The following are command params output by the --help param from the script:

```shell
Command-line driver for patron group ETL jobs.

optional arguments:
-h, --help            show this help message and exit
--config CONFIG       path to configuration file for this ETL run
--group GROUP         name of patron group (a.k.a. section) in configuration
                    file for this ETL run
--ldap_host LDAP_HOST
                    LDAP host
--ldap_base_dn LDAP_BASE_DN
                    base DN for LDAP bind and query
--ldap_user LDAP_USER
                    user name for LDAP login
--ldap_passwd LDAP_PASSWD
                    password for LDAP login
--ldap_query LDAP_QUERY
                    query string for LDAP search
--grouper_host GROUPER_HOST
                    Grouper host
--grouper_base_path GROUPER_BASE_PATH
                    base path for Grouper API
--grouper_user GROUPER_USER
                    user name for Grouper login
--grouper_passwd GROUPER_PASSWD
                    password for Grouper login
--grouper_stem GROUPER_STEM
                    stem for Grouper query and update
--grouper_group GROUPER_GROUP
                    group for Grouper query and update
--batch_size BATCH_SIZE
                    synchronization batch size
--batch_timeout BATCH_TIMEOUT
                    synchronization batch timeout in seconds
--batch_delay BATCH_DELAY
                    delay between batches in seconds
--sync                perform synchronization
--sync_max SYNC_MAX   maximum membership delta to allow when synchronizing
--debug               turn on debug logging
--slack SLACK         redirect logging to Slack webhook
```

Petal configuration

Package configuration is set in src/main/python/config/petl.ini. (While this is the default configuration for the petl script, it would be nice to someday be able to load appended override configs from outside the package!) It loads the configuration for each individual Grouper group and enumerates the global defaults for the script if not set in command line arguments. See the header of the petl.ini for details:

#
# Configuration for the "petl" script.
#
# Parameters are loaded in the following order:
#
#   1. Global defaults.
#   2. Per-group configurations (will override #1).
#   3. Command-line parameters (will override #1 and #2).
#

#
# Global defaults for all groups.
#

[global]
ldap_host         = eds.iam.arizona.edu
ldap_base_dn      = dc=eds,dc=arizona,dc=edu
ldap_user         = ual-pgrps
ldap_passwd       = ***override***
grouper_host      = grouper.iam.arizona.edu
grouper_base_path = grouper-ws/servicesRest/json/v2_2_001/groups
grouper_user      = ual-pgrps
grouper_passwd    = ***override***
grouper_stem      = arizona.edu:dept:LBRY:pgrps
batch_size        = 100
batch_timeout     = 60
batch_delay       = 0
sync_max          = 1000

#
# Per-group configurations.
#
...

Maintainers

UA Libraries, TeSS-Dev Team