Check whether the opal-client has latest data

[hongbo-miao]

EDIT: created the feature request ticket at https://github.com/authorizon/opal/issues/154

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A similar question to Check whether the opal-client has latest policy, but for data instead of policy.

As for data, we send POST http://localhost:7002/data/config command to opal-server with HTTP body telling where it can pull the data. Once opal-client receives from opal-server, it will start to pull the data.

Is it possible for us to know

• When is the last time opal-client succeed pulling the data.
• If continues failing, when is the last time it tries.

I think this can solves by parsing opal-client logs. However, does it make sense to have some health APIs just like policy?

[orweis]

Hi @hongbo-miao the same transaction mechanism that @asafc described in https://github.com/authorizon/opal/discussions/148, and in the mentioned docs applies to data updates.

Meaning a data update will invalidate the health-query state.

The easiest way in my opinion to track this, is through the Webhook feature of OPAL transactions, i.e. you can have every OPAL-client report to a URL of your choice when it completes an update transaction.

To see how to utilize this callbacks / webhook mechanism checkout this document:
https://docs.opal.ac/tutorials/healthcheck_policy_and_update_callbacks#-data-update-callbacks

You can setup a service that listens to events and keeps track of the updates given to each client.
We can of course look into embedding this kind of service as part of OPAL (e.g. by having the OPAL servers track these events for example, but this is not something we have on the immediate roadmap)

Eager to hear what you think.

[hongbo-miao]

Right, I forgot the callback method!

I am wondering does it make sense to add some timestamps such as last_succeed_timestamp and last_tried_timestamp under both last_data_transaction and last_policy_transaction to the API

GET http://localhost:8181/v1/data/system/opal

which currently returns

{
    "result": {
        "healthy": true,
        "last_data_transaction": {
            "actions": [
                "set_policy_data"
            ],
            "error": "",
            "id": "216ea8174bb84c7490217b24520fead9",
            "success": true
        },
        "last_policy_transaction": {
            "actions": [
                "set_policies"
            ],
            "error": "",
            "id": "6d849b1ce92bae05c31146470e66e07c3c41b164",
            "success": true
        },
        "ready": true
    }
}

[orweis]

Yes,
timestamps are definitely something that makes sense adding here, also came up in this issue: https://github.com/authorizon/opal/issues/149

We can maybe look at adding those next week.
CC: @obsd