Simplify Docker host resolution logic: use default endpoint if not explicitly set

.forgejo/workflows/publish-container.yml

@@ -16,8 +16,8 @@ jobs:
   publish:
     runs-on: docker
     env:
-      # Allow explicit override from Forgejo variables.
+      # Use explicit override when provided, otherwise use the known-good host
-      DOCKER_HOST: ${{ vars.DOCKER_HOST }}
+      DOCKER_HOST: ${{ vars.DOCKER_HOST != '' && vars.DOCKER_HOST || 'tcp://172.17.0.1:2375' }}
 
     steps:
       - name: Checkout
@@ -65,35 +65,8 @@ jobs:
           echo "${HOME}/.local/bin" >> "${GITHUB_PATH}"
           "${HOME}/.local/bin/docker" --version
 
-      - name: Resolve Docker daemon endpoint
+      # Simplified: we trust DOCKER_HOST (default to tcp://172.17.0.1:2375). If you
-        run: |
+      # need a different endpoint, set the Forgejo variable `DOCKER_HOST`.
-          set -eu
-
-          if [ -n "${DOCKER_HOST:-}" ]; then
-            echo "Using configured DOCKER_HOST=${DOCKER_HOST}"
-            echo "DOCKER_HOST=${DOCKER_HOST}" >> "${GITHUB_ENV}"
-            exit 0
-          fi
-
-          if [ -S /var/run/docker.sock ]; then
-            echo "DOCKER_HOST=unix:///var/run/docker.sock" >> "${GITHUB_ENV}"
-            echo "Resolved DOCKER_HOST from local docker socket"
-            exit 0
-          fi
-
-          # Try a set of common candidate endpoints reachable from inside job containers.
-          CANDIDATES="forgejo-docker-in-docker host.docker.internal 172.17.0.1 172.18.0.1 10.0.2.2"
-          for c in $CANDIDATES; do
-            echo "Testing http://${c}:2375/_ping ..."
-            if curl --silent --max-time 2 "http://${c}:2375/_ping" >/dev/null 2>&1 || curl --silent --max-time 2 "http://${c}:2375/version" >/dev/null 2>&1; then
-              echo "DOCKER_HOST=tcp://${c}:2375" >> "${GITHUB_ENV}"
-              echo "Resolved DOCKER_HOST to tcp://${c}:2375"
-              exit 0
-            fi
-          done
-
-          echo "Could not determine a reachable Docker daemon endpoint from candidates. Set vars.DOCKER_HOST explicitly."
-          exit 1
 
       - name: Check Docker daemon connectivity
         run: |