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pyceo

CEO (CSC Electronic Office) is the tool used by CSC to manage club accounts and memberships. See architecture.md for an overview of its architecture.

Development

First, make sure that you have installed the syscom dev environment. This will setup all of the services needed for ceo to work. You should clone this repo in the phosphoric-acid container under ctdalek's home directory; you will then be able to access it from any container thanks to NFS.

Environment setup

Once you have the dev environment setup, there are a few more steps you'll need to do for ceo.

Kerberos principals

First, you'll need ceod/<hostname> principals for each of phosphoric-acid, coffee and mail. (coffee is taking over the role of caffeine for the DB endpoints). For example, in the phosphoric-acid container:

kadmin -p sysadmin/admin
<password is krb5>
addprinc -randkey ceod/phosphoric-acid.csclub.internal
ktadd ceod/phosphoric-acid.csclub.internal

Do this for coffee and mail as well. You need to actually be in the appropriate container when running these commands, since the credentials are being added to the local keytab. On phosphoric-acid, you will additionally need to create a principal called ceod/admin (remember to addprinc and ktadd).

Database

TODO - Andrew

Dependencies

Next, install and activate a virtualenv:

sudo apt install libkrb5-dev libsasl2-dev python3-dev
python3 -m venv venv
. venv/bin/activate
pip install -r requirements.txt
pip install -r dev-requirements.txt

C bindings

Due to the lack of a decent Python library for Kerberos we ended up writing our own C bindings using cffi. Make sure you compile the bindings:

cd ceo_common/krb5
python krb5_build.py

This should create a file named '_krb5.cpython-37m-x86_64-linux-gnu.so'. This will be imported by other modules in ceo.

Running the application

ceod is a distributed application, with instances on different hosts offering different services. Therefore, you will need to run ceod on multiple hosts. Currently, those are phosphoric-acid, mail and caffeine (in the dev environment, caffeine is replaced by coffee).

To run ceod on a single host (as root, since the app needs to read the keytab):

export FLASK_APP=ceod.api
export FLASK_ENV=development
flask run -h 0.0.0.0 -p 9987

Sometimes changes you make in the source code don't show up while Flask is running. Stop the flask app (Ctrl-C), run clear_cache.sh, then restart the app.

Interacting with the application

The client part of ceo hasn't been written yet, so we'll use curl to interact with ceod for now.

ceod uses SPNEGO for authentication, and TLS for confidentiality and integrity. In development mode, TLS can be disabled.

First, make sure that your version of curl has been compiled with SPNEGO support:

curl -V

Your should see 'SPNEGO' in the 'Features' section.

The API also uses unconstrained Kerberos delegation when interacting with the LDAP database. This means that the client obtains a forwarded TGT, then sends that to ceod, which then uses it to interact with LDAP on the client's behalf. There is a script called gen_cred.py which can generate this ticket for you.

Here's an example of making a request to an endpoint which writes to LDAP:

# Get a Kerberos TGT first
kinit
# Obtain a forwarded TGT
./gen_cred.py phosphoric-acid
# Make the request
curl --negotiate -u : --service-name ceod \
    -H "X-KRB5-CRED: $(cat cred)" \
    -d '{"uid":"test_1","cn":"Test One","program":"Math","terms":["s2021"]}' \
    -X POST http://phosphoric-acid:9987/api/members

Miscellaneous

Mailman

You may wish to add more mailing lists to Mailman; by default, only the csc-general list exists (from the dev environment playbooks). Just attach to the mail container and run the following:

/opt/mailman3/bin/mailman create new_list_name@csclub.internal

See https://git.uwaterloo.ca/csc/syscom-dev-environment/-/tree/master/mail for instructions on how to access the Mailman UI from your browser.

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