feat: ARM64 support

[yanksyoon]

Applicable spec: ISD097

Overview

Adds support for ARM64 deployment for bare metal arm64 machines (for non-bare metal machines, arm v8.3a or higher is required which supports nested virtualizations. See https://developer.arm.com/documentation/102142/0100/Nested-virtualization)

Link to successful CI runs: https://github.com/yanksyoon/selfhostedtest/actions/runs/7057746518/job/19211975867

Rationale

To support ARM64 workloads.

Juju Events Changes

None.

Module Changes

charm_state.py adds a method to determine current architecture.
runner.py introduces arm64 yq binary url.

Library Changes

None.

Checklist

• The charm style guide was applied
• The contributing guide was applied
• The changes are compliant with ISD054 - Managing Charm Complexity
• The documentation is generated using src-docs
• The documentation for charmhub is updated.
• The PR is tagged with appropriate label (urgent, trivial, complex)

Documentation on Charmhub should automatically be updated with the upload-charm-docs workflow.

[yanksyoon]

Some comments to help review.

[jdkandersson]

Could we change the title to not include bare metal since that is more a question of what is supported by the hardware rather than what the charm supports please?

[yanksyoon]

@jdkandersson Updated, thank you!

[cbartz]

LGTM, Just one small comment.

[github-actions]

Test coverage for ac10133

Name                    Stmts   Miss Branch BrPart  Cover   Missing
-------------------------------------------------------------------
src/charm.py              429     98    107     25    75%   79-80, 86-88, 112-113, 117-119, 155-157, 167->179, 177, 220-228, 240-244, 275, 352-357, 378, 395-396, 405-428, 446-448, 456-459, 466, 469-470, 486, 491-496, 541->544, 557-558, 560-561, 595-602, 626-627, 639-641, 656-657, 682-683, 685-686, 688-689, 763->765, 826-827, 843, 861-863, 867
src/charm_state.py         75      6     10      0    91%   90-97
src/errors.py              34      0      0      0   100%
src/event_timer.py         42      8      4      0    74%   94-97, 117-120
src/firewall.py            43     25     10      0    38%   38-42, 64-67, 75-149
src/github_type.py         36      0      0      0   100%
src/lxd_type.py            37      0      2      0   100%
src/metrics.py             67      2     10      1    96%   60->63, 150-151
src/runner.py             344     70    110     26    75%   50->52, 128, 226-233, 239-245, 272-273, 317-326, 350-355, 360, 380, 384-394, 443->446, 449-451, 458, 472, 482, 486, 488, 504, 552-557, 573-586, 597-629, 634, 672, 718-720, 724, 742, 777, 803, 808-820, 834, 854, 870
src/runner_manager.py     274     26    102      9    90%   166, 219-221, 234-235, 247-249, 255-260, 264-265, 275-276, 295, 424, 443-447, 472, 555, 704, 724
src/runner_metrics.py     112      5     22      2    95%   133-134, 146, 215-216
src/runner_type.py         55      0     12      0   100%
src/shared_fs.py           80     10     12      0    89%   73-74, 160-161, 166-167, 173-174, 196-197
src/utilities.py           68      6     20      8    84%   74->76, 78->84, 89-91, 121, 135, 173, 226
-------------------------------------------------------------------
TOTAL                    1696    256    421     71    82%

Static code analysis report

Run started:2023-12-05 06:32:33.691133

Test results:
  No issues identified.

Code scanned:
  Total lines of code: 3776
  Total lines skipped (#nosec): 0
  Total potential issues skipped due to specifically being disabled (e.g., #nosec BXXX): 10

Run metrics:
  Total issues (by severity):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
  Total issues (by confidence):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
Files skipped (0):