[wip][ci] try to build docker image

.gitlab-ci.yml

@@ -40,3 +40,9 @@ run:
   artifacts:
     paths:
       - dist/*.whl
+
+build:
+  image: docker:19.03.12-dind
+  script:
+    - apt-get install python3
+    - docker build -t halfapi .

Dockerfile

@@ -0,0 +1,7 @@
+# syntax=docker/dockerfile:1
+FROM docker.io/python:3.8.12-slim-bullseye
+COPY . /halfapi
+WORKDIR /halfapi
+RUN pip install .
+CMD gunicorn halfapi.app
+