Set UID and GID for github generated docker images

Explicitly set the user and group ids for images that will
be pushed ghcr by the docker workflow. This makes it easier
to manage permissions of the xfer directory when using images
from the registry.

Signed-off-by: Mic Bowman <[email protected]>

.github/workflows/docker.yml

@@ -47,14 +47,21 @@ jobs:
           echo "EVENT NAME: ${{ github.event.name }}"
           echo "MERGED: ${{ github.event.pull_request.merged }}"
 
+      # create the docker images with the user and group IDs
+      # set to 55172 (randomly chosen number unlikely to conflict
+      # with existing users). this helps to set permissions local
+      # file management with pulled images. Specifically, the
+      # following will make the xfer directory writeable by the
+      # images:
+      #   sudo chown -R 55172:55172 $PDO_SOURCE_ROOT/docker/xfer
       - name: Build Docker Images
         env:
           PDO_INTERPRETER: wawaka
           PDO_LOG_LEVEL: warning
         run: |
           git checkout -b ci-test-branch
           . build/common-config.sh
-          make -C docker
+          make -C docker PDO_USER_UID=55172 PDO_GROUP_UID=55172
 
       - name: Login to the ghcr.io Container Registry
         uses: docker/login-action@v2