How do you get an OpenStack service catalog via the Python API? It took me way too long with too much code digging to figure it out, so I’ll share.

Note that the following was tested on versions rocky and stein.

The way that works for anyone that can log into the identity node:

from keystoneauth1 import loading, identity, session, exceptions

auth = identity.Password(
    auth_url,
    username=username,
    password=password,
    user_domain_id="default",
    project_domain_id="default",
    project_name=project_name )
sess = session.Session( auth=auth )

# This step was not obvious. It doesn't seem 
# to be directly doable from the Session, 
# which seems like the more obvious approach.
auth_ref = sess.auth.get_auth_ref(sess)
catalog = auth_ref.service_catalog.get_endpoints( interface="public" )
service_endpoints = {}
for s_name in catalog:
    s = catalog[s_name]
    service_endpoints[s_name] = s[0]["url"]

# Here's a dictionary of service-type -> endpoint URL
service_endpoints

This was actually the second technique discovered. The technique below was the first, but it only works for users that have admin privileges to a project and (I think) reader privileges to the project services.

from keystoneauth1 import loading, identity, session, exceptions
import keystoneclient

auth = identity.Password(
    auth_url,
    username=username,
    password=password,
    user_domain_id="default",
    project_domain_id="default",
    project_name=project_name )
sess = session.Session( auth=auth )

keyclient = keystoneclient.client.Client(
    "3.0",
    session=sess )

service_endpoints = {}
service_list = keyclient.services.list()
for s in service_list:
    endpoints = keyclient.endpoints.list( enabled=True, service=s.id, interface="public" )
    service_endpoints[s.type] = endpoints[0].url

# Here's a dictionary of service-type -> endpoint URL
service_endpoints

Note that the URLs from this technique will not include project ID’s, instead including a token to be replaced: %(tenant_id)

I have opened a question on Ask OpenStack that might eventually result in a better option: https://ask.openstack.org/en/question/123404/how-to-get-service-catalog-with-python-api/#123445