Detect native arch dynamically

[zacksiri]

Currently from what I read from the setup script. It seems anything which is not x86 will setup qemu. However in the use case where we're using a self hosted runner that the host is natively aarch64 it should not setup qemu.

[zacksiri]

If you can give me pointers I can probably handle this and submit a PR.

Update:

After some research can't we use uname -m to detect the architecture? If the argument passed in doesn't match we provision qemu.

[joeyparrish]

I have the same issue. This fails on my arm64 runner, because it can't execute the x86 binaries. And on this line:

setup-alpine/setup-alpine.sh

Line 181 in 359b91e

if [[ "$INPUT_ARCH" != x86* ]]; then

it sets up qemu for any architecture that isn't x86. Instead, it should set up qemu for any architecture that isn't native.

[joeyparrish]

Also this default is a problem:

setup-alpine/action.yml

Lines 9 to 15 in 359b91e

	apk-tools-url:
	description: >
	URL of the apk-tools static binary to use. It must end with `#!sha256!` followed by a SHA-256
	hash of the file.
	This should normally be left at the default value.
	required: false
	default: https://gitlab.alpinelinux.org/api/v4/projects/5/packages/generic/v2.14.0/x86_64/apk.static#!sha256!1c65115a425d049590bec7c729c7fd88357fbb090a6fc8c31d834d7b0bc7d6f2

It hard-codes for x86_64 binaries, and requires a sha256 to be valid.