From 12c1c919378e4f699ebcf87bfb864027647ca543 Mon Sep 17 00:00:00 2001
From: Douglas Camata <159076+douglascamata@users.noreply.github.com>
Date: Thu, 1 Feb 2024 21:33:05 +0100
Subject: [PATCH] Quick failure on M-series (arm64) macOS runners  (#28)

* Check wether M1 detection works

Signed-off-by: Douglas Camata <159076+douglascamata@users.noreply.github.com>

* Test action on macOS 13 only

Signed-off-by: Douglas Camata <159076+douglascamata@users.noreply.github.com>

* Update README

Signed-off-by: Douglas Camata <159076+douglascamata@users.noreply.github.com>

* Keep macOS 12 in the test matrix

Signed-off-by: Douglas Camata <159076+douglascamata@users.noreply.github.com>

* Change safety check to be futureproof

Signed-off-by: Douglas Camata <159076+douglascamata@users.noreply.github.com>

* Readd macos-14 for another quick test

Signed-off-by: Douglas Camata <159076+douglascamata@users.noreply.github.com>

* Fix bash-fu

Signed-off-by: Douglas Camata <159076+douglascamata@users.noreply.github.com>

* Another README update

Signed-off-by: Douglas Camata <159076+douglascamata@users.noreply.github.com>

* Remove macos-14 from matrix list after test

Signed-off-by: Douglas Camata <159076+douglascamata@users.noreply.github.com>

* Add changelog entry

Signed-off-by: Douglas Camata <159076+douglascamata@users.noreply.github.com>

---------

Signed-off-by: Douglas Camata <159076+douglascamata@users.noreply.github.com>
---
 .github/workflows/test.yml |  6 +++++-
 CHANGELOG.md               |  5 +++++
 README.md                  | 19 +++++++++++++++++++
 action.yml                 | 13 ++++++++++++-
 4 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 5a9602d..c9f87fd 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -6,7 +6,11 @@ on:
 
 jobs:
   setup-docker:
-    runs-on: macos-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [macos-12, macos-13]
     name: A job to perform a self-test on this Github Action
     steps:
       # To use this repository's private action,
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4c4972e..fef04f7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning].
 
 ## [Unreleased]
 
+### Added
+
+- Fail fast when running on arm64 macOS runners (`macos-14` public runners) ([#28](https://github.com/douglascamata/setup-docker-macos-action/pull/28)).
+  - None of the arm64 processors on Apple computers support nested virtualization as of today (Feb 1st 2024).
+
 ## [v1-alpha.11] - 2024-01-05
 
 ### Added
diff --git a/README.md b/README.md
index 9766b5e..febf82f 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,25 @@ I intend this action to be kept as simple as possible:
 - No other OS will be supported.
 - Binaries will be downloaded directly from the source when possible.
 
+# Currently supported public runner images
+
+- `macos-12`
+- `macos-13`
+
+# ARM64 processors (M1, M2, M3 series) used on `macos-14` images are unsupported!
+
+Yes, exactly what you just read. These processors do not support nested
+virtualization. This means Colima can't start the VM to run Docker.
+
+For the M1 processor there is no hope. It lacks the hardware support for this.
+
+The M2 and M3 processors have such hardware support, but no software support
+from Apple's Hypervisor framework (so no hopes for QEMU) or Virtualization
+framework (alternative to QEMU).
+
+I'm sorry, but there's nothing I can do about it. All we can do is wait. If I
+miss the announcement of nested virtualization support, please open an issue.
+
 ## Features
 
 - Safety check to ensure the action is running in macOS.
diff --git a/action.yml b/action.yml
index 58f98e3..2169d83 100644
--- a/action.yml
+++ b/action.yml
@@ -30,12 +30,23 @@ outputs:
 runs:
   using: "composite"
   steps:
-    - name: Safety check
+    - name: OS safety check
       if: runner.os != 'macOS'
       run: |
         echo "Not a macOS runner, exiting."
         exit 1
       shell: bash
+    - name: ARM64 safety check
+      run: |
+        arch_name=$(uname -m)
+        if [ "$arch_name" = "arm64" ]
+        then
+            echo "Detected M-series processor runner without nested virtualization support, exiting."
+            exit 1
+        else
+            echo "Running on supported architecture: ${arch_name}"
+        fi
+      shell: bash
     - name: Update Homebrew
       run: |
         echo "::group::Updating Homebrew"