diff --git a/.github/workflows/docker.yml b/.github/workflows/docker.yml
index 39edc64fc0..425f4e05e8 100644
--- a/.github/workflows/docker.yml
+++ b/.github/workflows/docker.yml
@@ -23,7 +23,11 @@ jobs:
           password: ${{ secrets.DOCKER_PASSWORD }}
           tag_semver: true
           cache: ${{ github.event_name != 'schedule' }}
-      - name: Test
+      - name: Test1
+        run: which docker || true
+      - name: Test2
         run: |
+          ls -lrt .
+          which docker || true
           docker run -d -p 8080:80 -e SUPERVISORD_LOG_LEVEL=debug -e SECRET_KEY_BASE=secret ${{ steps.build_and_push.outputs.digest }}
-          curl --fail -k --retry 10 --retry-connrefused -vvv http://localhost:8080/api/v3
+          curl --fail -k --retry 10 http://localhost:8080/api/v3
diff --git a/.github/workflows/pullpreview.yml b/.github/workflows/pullpreview.yml
index 2a8c0bded4..d1243b24e2 100644
--- a/.github/workflows/pullpreview.yml
+++ b/.github/workflows/pullpreview.yml
@@ -1,10 +1,8 @@
 name: PullPreview
 on:
   push:
-    branches:
-      - dev
   pull_request:
-    types: [labeled, unlabeled, closed, reopened, synchronized]
+    types: [labeled, unlabeled, closed]
 
 jobs:
   deploy:
diff --git a/Dockerfile b/Dockerfile
index 8bd0a7f15e..938f94003b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1 +1,72 @@
-FROM nginx
+FROM ruby:2.6-stretch AS pgloader
+RUN apt-get update -qq && apt-get install -y libsqlite3-dev make curl gawk freetds-dev libzip-dev
+COPY docker/mysql-to-postgres/bin/build /tmp/build-pgloader
+RUN /tmp/build-pgloader && rm /tmp/build-pgloader
+
+FROM ruby:2.6-stretch
+MAINTAINER operations@openproject.com
+
+# Allow platform-specific additions. Valid values are: on-prem,saas,bahn
+ARG PLATFORM=on-prem
+# Use OAuth token in case private gems need to be fetched
+ARG GITHUB_OAUTH_TOKEN
+ARG DEBIAN_FRONTEND=noninteractive
+
+ENV NODE_VERSION="12.18.3"
+ENV BUNDLER_VERSION="2.0.2"
+ENV BUNDLE_PATH__SYSTEM=false
+ENV APP_USER=app
+ENV APP_PATH=/app
+ENV APP_DATA_PATH=/var/openproject/assets
+ENV APP_DATA_PATH_LEGACY=/var/db/openproject
+ENV PGBIN="/usr/lib/postgresql/9.6/bin"
+ENV PGDATA=/var/openproject/pgdata
+ENV PGDATA_LEGACY=/var/lib/postgresql/9.6/main
+
+ENV DATABASE_URL=postgres://openproject:openproject@127.0.0.1/openproject
+ENV HEROKU=true
+ENV RAILS_ENV=production
+ENV RAILS_CACHE_STORE=memcache
+ENV RAILS_GROUPS="production docker opf_plugins"
+ENV OPENPROJECT_INSTALLATION__TYPE=docker
+# Valid values are: standard,bim
+ENV OPENPROJECT_EDITION=standard
+ENV NEW_RELIC_AGENT_ENABLED=false
+ENV ATTACHMENTS_STORAGE_PATH=$APP_DATA_PATH/files
+# Set a default key base, ensure to provide a secure value in production environments!
+ENV SECRET_KEY_BASE=OVERWRITE_ME
+
+COPY --from=pgloader /usr/local/bin/pgloader-ccl /usr/local/bin/
+
+WORKDIR $APP_PATH
+
+COPY docker/setup ./docker/setup
+RUN ./docker/setup/preinstall.sh
+
+COPY Gemfile ./Gemfile
+COPY Gemfile.* ./
+COPY modules ./modules
+COPY vendor ./vendor
+# some gemspec files of plugins require files in there, notably OpenProject::Version
+COPY lib ./lib
+
+RUN bundle install --quiet --deployment --path vendor/bundle --no-cache \
+  --with="$RAILS_GROUPS" --without="test development" --jobs=8 --retry=3 && \
+  rm -rf vendor/bundle/ruby/*/cache && rm -rf vendor/bundle/ruby/*/gems/*/spec && rm -rf vendor/bundle/ruby/*/gems/*/test
+
+# Finally, copy over the whole thing
+COPY . .
+
+RUN ./docker/setup/postinstall.sh
+
+# Expose ports for apache and postgres
+EXPOSE 80 5432
+
+# Expose the postgres data directory and OpenProject data directory as volumes
+VOLUME ["$PGDATA", "$APP_DATA_PATH"]
+
+# Set a custom entrypoint to allow for privilege dropping and one-off commands
+ENTRYPOINT ["./docker/entrypoint.sh"]
+
+# Set default command to launch the all-in-one configuration supervised by supervisord
+CMD ["./docker/supervisord"]