Set the UMASK in the entry script, added some brief step documentation, also Gitea action workflow attempt.

.gitea/workflows/build-docker-image-and-push.yaml

@@ -0,0 +1,32 @@
+name: Build foundry vtt docker image and push to registry
+run-name: ${{ gitea.actor }} is building image and pushing to registry
+
+on:
+  push:
+    branches:
+      - 'main'
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+#      -
+#        name: Checkout
+#        uses: actions/checkout@v4
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      -
+        name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          registry: dockerregistry:5000
+          username: ${{ secrets.REGISTRY_USERNAME }}
+          password: ${{ secrets.REGISTRY_PASS }}
+      -
+        name: Build and push
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          tags: foundryvtt-docker:latest

Dockerfile

@@ -3,25 +3,26 @@ LABEL maintainer="crovaxon"
 
 WORKDIR /app
 
+# user and group id are typical defaults for UNRAID
 ENV PUID=99
 ENV PGID=100
 ENV UMASK=022
 ENV PATH="/app:${PATH}"
 
-#RUN addgroup -g ${GUID} foundry
-#RUN adduser -H -u ${PUID} -s /bin/bash foundry foundry
-#USER foundry
-
+# update and install requirements
 RUN apk update & apk add --no-cache ca-certificates libstdc++ su-exec bash-completion tar nodejs npm
 
+# copy entrypoint script to work directory
 COPY entrypoint.sh ./
 
-# directory of the Foundry application
+# mount volume directory of the Foundry application
 VOLUME /foundry
-#directory of the Foundry user data
+
+# mount volume directory of the Foundry user data
 VOLUME /foundrydata
 
-# default TCP port
+# expose default TCP port
 EXPOSE 30000
 
+#run entrypoint
 ENTRYPOINT ["/app/entrypoint.sh"]

entrypoint.sh

@@ -1,4 +1,10 @@
 #!/bin/sh
 
+# set umask
+umask ${UMASK}
+
+# set permissions on application folder 
 chown -R ${PUID}:${PGID} /foundry
+
+# run Foundry with the environmentally set user and group id
 exec su-exec ${PUID}:${PGID} node /foundry/resources/app/main.js --dataPath=/foundrydata