Simplify report importing

[2opremio]

A user came up with the following usecase:

freezing’ Scope’s view, so that I can ZIP up a static web site

We devs do this all the time for debugging by exporting the Scope report and loading it with a fixprobe. However, this is really tedious for end users.

I see a couple of alternatives to make this easier:

1. Implement the fixprobe functionality in the UI. The UI can temporarily act as a fixprobe while the report is "imported". Some things would need to be resolved though: When to stop forwarding the report? What about other probes reporting at the same time? We may need to ask the app to ignore them temporarily, which won't be easy for weave cloud.
2. Implement scope launch --diagnose=report.json. Which launches an app with a fixed probe.

While (1) is more flexible (it works with existing instances) it's also much more complicated, so I would go for (2).

An issue for both (1) and (2) is forward compatibility of the standalone app with newer report schemas (which we have never worried about). We can choose to ignore that problem for now.

[rade]

We already almost can do (2), by invoking the scope binary directly, e.g.

prog/scope --mode=app --app.collector=file:/home/matthias/Downloads/report.json 

works, but the same doesn't work via a scope launch because the file isn't available inside the container. A new launch flag, along the lines suggested above, and parsed by the script could easily take care of mounting the file.