try set docker GID

Author: chrmarti

.github/workflows/ci_common.yml

@@ -767,6 +767,10 @@ jobs:
       - name: UID INFO
         run: echo 'UID INFO'; id; ls -l /var/run/docker.sock
 
+      - name: Set DOCKER_GID
+        run: |
+          echo "DOCKER_GID=$(getent group docker | cut -d: -f3)" >> $GITHUB_ENV
+
       - name: Run test
         uses: ./
         with:
@@ -778,6 +782,8 @@ jobs:
           eventFilterForPush: |
             push
             pull_request
+        env:
+          DOCKER_GID: ${{ env.DOCKER_GID }}
 
   test-gh-docker-from-docker-root:
     name: Run GitHub docker-from-docker-root test

github-tests/Dockerfile/docker-from-docker-non-root/.devcontainer/Dockerfile

@@ -52,7 +52,13 @@ COPY scripts/docker-client.sh /tmp/
 RUN /tmp/docker-client.sh
 
 #Add user to docker group
-RUN sudo groupadd docker && sudo usermod -aG docker $USERNAME && newgrp docker
+ARG DOCKER_GID=
+RUN if [ -n "$DOCKER_GID" ]; then \
+    sudo groupadd -g $DOCKER_GID docker; \
+    else \
+    sudo groupadd docker; \
+    fi \
+    && sudo usermod -aG docker $USERNAME
 
 # __DEVCONTAINER_SNIPPET_INSERT__ (control where snippets get inserted using the devcontainer CLI)
 

github-tests/Dockerfile/docker-from-docker-non-root/.devcontainer/devcontainer.json

@@ -4,6 +4,9 @@
 	"name": "dc-test",
 	"dockerFile": "Dockerfile",
 	"build": {
+		"args": {
+			"DOCKER_GID": "${localEnv:DOCKER_GID}"
+		},
 		"cacheFrom": "ghcr.io/devcontainers/ci/tests/docker-from-docker-non-root:latest"
 	},