Inspired by the number of ARM users we have (and because I want to rip out the only 32 bit test we have which without this PR would remove all tests we have on non-x86_64 architectures), this test adds an ARM image to the test farm tests. The image ID was taken from https://wiki.debian.org/Cloud/AmazonEC2Image/Stretch, you can see tests passing at https://travis-ci.com/certbot/certbot/builds/116857897, and I ran test_tests.sh locally and it passed.
Fixes#6955.
This updates the Fedora version used in our test farm tests to Fedora 30. The AMI ID comes from https://alt.fedoraproject.org/cloud/ where it is listed as their standard HVM AMI for the region we use us-east-1 (US East (N. Virginia)).
Unfortunately, there were a lot of small changes required for this. The big reason for this is on Fedora, there isn't a Python 2 executable installed. In fact, there's not even an executable named python. It's just python3. Rather than installing another Python in each test, I wrote a script that the test scripts can share to figure out the different paths and names that should be used in their script. (This isn't used in test_sdists.sh because the logic is a little different.)
Other changes here worth flagging are:
I changed the name of the variable RUN_PYTHON3_TESTS in test_leauto_upgrades.sh to RUN_RHEL6_TESTS. The tests that are run when this variable is set test the upgrade from Python 2 to Python 3 on RHEL 6. I think this new name is much better now that we also have Fedora running Python 3.
I made tools/simple_http_server.py work on Python 3.
You can see tests passing with these changes at https://travis-ci.com/certbot/certbot/builds/113821476. I also ran test_tests.sh and they passed.
* Update to Fedora 30 in test farm tests.
Fedora 28 is likely to reach its EOL soon.
* Add set_python_envvars.sh.
* Fix test_apache2.sh on python3 only distros.
* Fix test_leauto_upgrades.sh on python3 systems.
* Fix certonly_standalone tests with python3 only
* Fix test_sdists.sh on python3 only distros.
* Make simple_http_server.py work on Python 3.
* add comments
