Add ARM support

[dlanderson]

We've added linux ARM support (aarch64) for the core agent binary in version 1.3.1. We need to add ARM architecture detection on linux for the Python agent.

On AWS graviton instance:

ubuntu@ip-172-31-58-208:~$ uname -a
Linux ip-172-31-58-208 5.4.0-1045-aws #47-Ubuntu SMP Tue Apr 13 07:04:23 UTC 2021 aarch64 aarch64 aarch64 GNU/Linux

Note: I didn't try 3.9
Python 3.8

ubuntu@ip-172-31-58-208:~$ python3 --version
Python 3.8.10
ubuntu@ip-172-31-58-208:~$ python3
Python 3.8.10 (default, Jun  2 2021, 10:49:15)
[GCC 9.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import platform;
>>> platform.machine()
'aarch64'
>>>

Python 2.7:

ubuntu@ip-172-31-58-208:~$ python --version
Python 2.7.18

ubuntu@ip-172-31-58-208:~$ python
Python 2.7.18 (default, Mar  8 2021, 13:02:45)
[GCC 9.3.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import platform;
>>> platform.machine()
'aarch64'
>>>

The core agent 1.3.1 builds available:

core-agent-v1.3.1-aarch64-unknown-linux-gnu
core-agent-v1.3.1-aarch64-unknown-linux-musl
core-agent-v1.3.1-i686-unknown-linux-gnu
core-agent-v1.3.1-i686-unknown-linux-musl
core-agent-v1.3.1-x86_64-apple-darwin
core-agent-v1.3.1-x86_64-unknown-linux-gnu
core-agent-v1.3.1-x86_64-unknown-linux-musl

[tim-schilling]

@dlanderson Sorry, I'm a bit confused on the details here. What's the functional change you're looking for?

[dlanderson]

I think this needs:

• aarch64 added as an option at https://github.com/scoutapp/scout_apm_python/blob/master/src/scout_apm/core/platform_detection.py#L21 and any associated tests.
• Bump core-agent version default to 1.3.1
• We don't build for darwin ARM (M1 Machines), so we should still use core-agent-v1.3.1-x86_64-apple-darwin even if we detect something other than x86_64 on macs (Rosetta will run x86 binaries on M1 macs just fine). From brief searching there are different archs returned for M1 on certain python versions.
• Do any versions of python return anything other than aarch64?

[tim-schilling]

Thank you for the clarifications.

Do any versions of python return anything other than aarch64?

I imagine this depends on the machine that's being used. From what I can tell, python will try to make use of linux's uname command.

Can you share some of those searches with me that said different architectures are returned when using M1?

[tim-schilling]

Using Amazons ARM-64 image, I tested this with py2.7, 3.5-3.10. All returned aarch64.