Upgrade utility scripts to Python 3

[wkozaczuk]

Given the Python end-of-life scheduled for Jan 1st, 2020, we should upgrade at least the key scripts (setup.py, module.py, test.py, etc) under script to be Python 3 compatible.

Please see https://docs.python.org/3/howto/pyporting.html

[lgoldstein]

I second this - I recently installed Ubuntu 18 and it comes with Python 3 and not 2 (I can install Python 2 as well, but IMO it would not be advisable).

[BassMatt]

Hi!

I submitted a patch with a few changes to all the files listed in scripts/README to update them to python3.

I was wondering if the files in scripts/osv/, and scripts/trace.py were in scope? I spent a little bit of time updating them but they seemed to do some more complicated things with prof.py, so I'm looking for a bit of guidance first..

[wkozaczuk]

@BassMatt thanks for the patch. Please address the minor issues others pointed on the mailing list and we will apply it.
Regarding what is in scope I think that both scripts/trace.py and scripts/osv/* are. Though I would leave the prof.py for now as I am not sure how much used it used. In general, the most important ones are scripts/run.py and others used by it directly or indirectly as well as all the python files used by script/build (module.py, etc).

[wkozaczuk]

Following python files have been identified as 'in use' or deemed as possibly useful in the near future:

./modules/httpserver-api/json2code.py
./modules/httpserver-api/tests/api/testenv.py 
./modules/httpserver-api/tests/api/testfile.py
./modules/httpserver-api/tests/api/testfs.py 
./modules/httpserver-api/tests/api/testjolokia.py
./modules/httpserver-api/tests/api/testjvm.py
./modules/httpserver-api/tests/api/testnetwork.py
./modules/httpserver-api/tests/api/testos.py 
./modules/httpserver-api/tests/api/testtrace.py 
./modules/httpserver-api/tests/basetest.py
./modules/httpserver-api/tests/testhttpserver-api.py
./modules/httpserver-html5-gui/tests/static/teststatic.py
./modules/httpserver-html5-gui/tests/testhttpserver.py
./modules/openjdk8-from-host/module.py
./scripts/export_manifest.py
./scripts/firecracker.py
./scripts/freq.py
./scripts/gen-rofs-img.py
./scripts/imgedit.py
./scripts/libosv.py
./scripts/loader.py
./scripts/manifest_common.py
./scripts/memory_analyzer.py
./scripts/metadata.py
./scripts/mkbootfs.py
./scripts/nbd_client.py
./scripts/osv/client.py
./scripts/osv/debug.py
./scripts/osv/modules/api.py
./scripts/osv/modules/filemap.py
./scripts/osv/modules/resolve.py
./scripts/osv/prof.py
./scripts/osv/trace.py
./scripts/osv/tree.py
./scripts/prof.py
./scripts/run.py
./scripts/setup.py
./scripts/tester.py
./scripts/test.py
./scripts/tests/test_app.py
./scripts/tests/test_app_with_test_script.py
./scripts/tests/test_http_app_with_curl_and_ab.py
./scripts/tests/testing.py
./scripts/tests/test_net.py
./scripts/tests/test_tracing.py
./scripts/top.py
./scripts/trace.py
./scripts/upload_manifest.py
./tests/tst-tcp-hash-cli.py