event store

[xgp]

Adding an EventStoreProvider implementation per #3

Submitting a DRAFT PR for feedback.

Current issues:

Schema questions

Need feedback on the schema, as I'm not experienced with Cassandra https://github.com/xgp/keycloak-cassandra-extension/blob/xgp/event-store/core/src/main/resources/cassandra/migration/0003_events.cql

Admin event resourcePath LIKE

Because LIKE queries require secondary indexes to be enabled in Cassandra, they are not currently supported for querying resourcePath of admin events.

Query performance

Performance of event queries using sparse fields (i.e. those generated by the Admin UI) are not performant, as Cassandra is forced to use ALLOW FILTERING. Future work could include a separate lookup table with client-side result filtering.

Pagination performance

Because Cassandra does not support OFFSET/LIMIT type queries, this is done in Java. This will likely consume significant resources for large event result sets.

[opdt]

Please squash your commits to one.

[opdt]

This should be done with external file based configuration and not hardcoded

[xgp]

Thanks @opdt I was having problems getting the migration to run in the tests without a timeout. Can you point me to some documentation/examples of how this is achieved using external file based configuration? I'm not super familiar with cassandra, so the options are new to me.

[xgp]

I've been struggling to figure out how to load an external file based configuration @opdt. Is there an example you're aware of?

[xgp]

Finally figured out how to load config from a file. I have a branch here, so let me know if you want me to do a separate PR. https://github.com/opdt/keycloak-cassandra-extension/compare/main...xgp:keycloak-cassandra-extension:xgp/config-file?expand=1

[opdt]

You dont need any custom code to load the config from a file. The cassandra driver does it automatically: https://docs.datastax.com/en/developer/java-driver/4.17/manual/core/configuration/ (application.conf in Classpath)

[xgp]

Correct. But if you want to allow it to be put somewhere else and not bundled with the jar, then you have to tell Cassandra where to load it from.

[xgp]

For example, I might want to have k8s mount the conf file in the pod and then need to tell the extension where to load it from. This decouples the configuration from the library.

[opdt]

Thats possible via -Dconfig.file=/path/to/application.confvia the underyling Lightbend configuration library (which also supports loading from other resources/URLs).
You can pass additional Java arguments via JAVA_OPTS_APPEND environment variable in Keycloak.

[xgp]

The problem I encounter when I specify that is that the init method still runs. So even though the underlying library supports the -Dconfig.file override, it appears that it never gets there because of the exceptions thrown when the variables are missing.

Also, if I set both, the variables in the config scope are what gets used.

[xgp]

Thank you @opdt Most requested updates made. I'll squash once we're done with all the changes. Please see my comments on two of the issues and let me know your answers/recommendations.