Fully parameterize build script in prep for multi-arch builds

.gitlab-ci.yml

@@ -7,17 +7,22 @@ default:
 'Build haswell':
   stage: 'build'
   tags: ['nest']
+  variables:
+    ARCH: 'x86_64'
+    CPU: 'haswell'
+    GENTOO_STAGE3_TAG: 'amd64'
   script:
     - 'mkdir debug'
     - 'buildah bud --pull --squash
                    --security-opt seccomp=unconfined
-                   --build-arg GENTOO_STAGE3_TAG=amd64
-                   --build-arg EMERGE_DEFAULT_OPTS="$CI_HOST_EMERGE_DEFAULT_OPTS --usepkg"
+                   --build-arg GENTOO_STAGE3_TAG="$GENTOO_STAGE3_TAG"
+                   --build-arg EMERGE_DEFAULT_OPTS="${CI_HOST_EMERGE_DEFAULT_OPTS} --usepkg"
                    --build-arg MAKEOPTS="$CI_HOST_MAKEOPTS"
-                   --build-arg PROFILE="haswell/server"
+                   --build-arg PROFILE="${CPU}/server"
+                   -v "/usr/bin/qemu-${ARCH}:/usr/bin/qemu-${ARCH}:ro"
                    -v "${PWD}/debug:/usr/lib/debug"
                    -v /nest:/nest
-                   -t "${CI_REGISTRY_IMAGE}:haswell" .'
-    - 'buildah bud -t "${CI_REGISTRY_IMAGE}/debug:haswell" -f Containerfile.debug .'
-    - 'buildah push "${CI_REGISTRY_IMAGE}:haswell"'
-    - 'buildah push "${CI_REGISTRY_IMAGE}/debug:haswell"'
+                   -t "${CI_REGISTRY_IMAGE}:${CPU}" .'
+    - 'buildah bud -t "${CI_REGISTRY_IMAGE}/debug:${CPU}" -f Containerfile.debug .'
+    - 'buildah push "${CI_REGISTRY_IMAGE}:${CPU}"'
+    - 'buildah push "${CI_REGISTRY_IMAGE}/debug:${CPU}"'