aarch64-linux remote builder configuration

Signed-off-by: Mika Tammi <[email protected]>

.github/workflows/build.yml

@@ -1,6 +1,10 @@
-# SPDX-FileCopyrightText: 2023 Technology Innovation Institute (TII)
+# SPDX-FileCopyrightText: 2023 Technology Innovation Institute (TII) and ghaf contributors
 #
 # SPDX-License-Identifier: Apache-2.0
+#
+# Based on tiiuae/ghaf-repository's workflow configuration, modified for this
+# project's purpose.
+#
 name: build
 
 on:
@@ -83,9 +87,8 @@ jobs:
         include:
           - arch: x86_64-linux
             target: caml-crush
-          # TODO
-          # - arch: aarch64-linux
-          #   target: caml-crush
+          - arch: aarch64-linux
+            target: caml-crush
     if: |
       always() &&
       needs.authorize.result == 'success' &&
@@ -131,6 +134,13 @@ jobs:
             trusted-public-keys = ghaf-dev.cachix.org-1:S3M8x3no8LFQPBfHw1jl6nmP8A7cVWKntoMKN3IsEQY= cache.vedenemo.dev:RGHheQnb6rXGK5v9gexJZ8iWTPX6OcSeS56YeXYzOcg= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
             substituters = https://ghaf-dev.cachix.org?priority=20 https://cache.vedenemo.dev https://cache.nixos.org
             system-features = nixos-test benchmark big-parallel kvm
+            builders-use-substitutes = true
+            builders = @/etc/nix/machines
+      - name: Configure remote builder
+        run: |
+          sudo sh -c "umask 377; echo '${{ secrets.BUILDER_SSH_KEY }}' >/etc/nix/id_builder_key"
+          sudo sh -c "echo '${{ secrets.BUILDER_SSH_KNOWN_HOST }}' >>/etc/ssh/ssh_known_hosts"
+          sudo sh -c "echo '${{ secrets.BUILDER_MACHINE_CONFIG }}' >/etc/nix/machines"
       - name: Check nix flake show runs successfully
         run: nix flake show
       - name: Check .nix formatting