ci: Allow building with merge-commit on forks (#355)

Signed-off-by: Oliver Koenig <[email protected]>

.github/workflows/_build_container.yml

@@ -29,12 +29,6 @@ jobs:
   main:
     runs-on: self-hosted-azure-builder
     steps:
-      - name: Checkout repository
-        uses: actions/checkout@v4
-        with:
-          path: ${{ github.run_id }}
-          ref: ${{ inputs.ref }}
-
       - name: Clean runner cache
         run: | 
           docker system prune --filter "until=24h" --force
@@ -58,7 +52,7 @@ jobs:
           push: true
           build-args: |
             MAX_JOBS=32
-            ALIGNER_COMMIT=${{ github.event.pull_request.head.sha || github.sha }}
+            ALIGNER_COMMIT=${{ inputs.ref }}
           cache-from: |
             nemoci.azurecr.io/nemo_aligner_container:${{ github.event.pull_request.number || 'buildcache' }}
             nemoci.azurecr.io/nemo_aligner_container:buildcache

Dockerfile

@@ -30,8 +30,7 @@ if [[ ! -d NeMo-Aligner ]]; then
     git clone https://github.com/NVIDIA/NeMo-Aligner.git
 fi
 cd NeMo-Aligner
-git fetch -a
-# -f since git status may not be clean
+git fetch origin '+refs/pull/*/merge:refs/remotes/pull/*/merge'
 git checkout -f $ALIGNER_COMMIT
 # case 1: ALIGNER_COMMIT is a local branch so we have to apply remote changes to it
 # case 2: ALIGNER_COMMIT is a commit, so git-pull is expected to fail