engine: plan how we expose all logs to mobile apps

[bassosimone]

This issue is about improving how we expose the engine logs to mobile apps. The main drawback we would like to address is that it's difficult for a user to see errors occurring in the mobile apps early during the experiment flow (more on this later). We will consider this issue resolved when we'll have a design and a plan to allow accessing logs.

More in detail, the current scheme is that we're passing logs to the mobile app while the test is running and the app will in turn do something sensible with these logs such as storing them. Yet, the main implementation drawback is that the app does not even bother with storing logs if an experiment fails early. This is a bummer because early logs are the ones that are more likely to be telling in case of blocking of our core services. Hence, we're basically hiding the most useful logs.

I suppose the first step is investigating if we can restructure logging in the app without changing the engine. It may be difficult since my understanding of why the app is not saving those logs is that there is really no test inside the database and so there is no logical "thing" know to the app that the logs may be attached to. If that turns out to be the case, maybe we can add some sort of "logcat" to the engine, which guarantees that at least we always have logs for the user.

[bassosimone]

So, previously, we said:

[...] We will consider this issue resolved when we'll have a design and a plan to allow accessing logs.

We now have a plan and a prototype here: ooni/probe-android#516.

We also have a second-step part of the plan here #2143.

Hence, we can consider this issue resolved.