Configure pull_request workflow runs using labels on Dom's self-hosted runner

.github/workflows/macos-dom.yaml

@@ -1,12 +1,18 @@
 name: macos-dom-build
 on:
-  #pull_request:
+  # uncomment if we decide to run tests when merging to develop branch
   #push:
+  #  # merges to develop branch
+  #  branches: [develop]
+  pull_request:
+    # pull request to develop with a label
+    types: [labeled]
+    branches: [develop]
   workflow_dispatch:
     inputs:
       template:
         description: 'Base spack.yaml template. Default is an empty environment.'
-        required: false
+        required: true
         default: 'jedi-ufs-all'
       specs:
         description: 'Which specs to add to the template. Default is none (empty string).'
@@ -20,6 +26,7 @@ defaults:
 
 jobs:
   macos-dom-build:
+    if: ${{ github.event.label.name == 'run-macos-dom' }}
     runs-on: [self-hosted, macOS, X64, macos-dom]
 
     steps:
@@ -31,9 +38,9 @@ jobs:
       - name: create-env
         run: |
           source ./setup.sh
-          spack stack create env --site macos.default --template ${{ inputs.template }} --name ${{ inputs.template }}.macos-dom
-          spack env activate -d envs/${{ inputs.template }}.macos-dom
-          spack add ${{ inputs.specs }}
+          spack stack create env --site macos.default --template ${{ inputs.template || 'jedi-ufs-all' }} --name ${{ inputs.template || 'jedi-ufs-all' }}.macos-dom
+          spack env activate -d envs/${{ inputs.template || 'jedi-ufs-all' }}.macos-dom
+          spack add ${{ inputs.specs || '' }}
 
           spack external find
           spack external find perl
@@ -46,8 +53,9 @@ jobs:
           spack concretize
           spack install --fail-fast
 
-      - name: upload-mirror
-        uses: actions/upload-artifact@v2
-        with:
-          name: spack_mirror
-          path: cache/source_cache
+      # Skip this - takes forever and isn't necessary
+      #- name: upload-mirror
+      #  uses: actions/upload-artifact@v2
+      #  with:
+      #    name: spack_mirror
+      #    path: cache/source_cache