Optimize Docker build

src/Dockerfile

@@ -4,10 +4,11 @@ FROM tiangolo/uwsgi-nginx:python3.7
 ENV LISTEN_PORT 8080
 EXPOSE 8080
 
-# Define environment
-COPY ./app /app
-RUN echo ${groupid} > /app/models/.env
 WORKDIR /app
+
+# The requirements file is copied first, so if there are no changes
+# docker will skip installing them again, and use a cached image instead
+COPY ./app/requirements.txt /app/
 ENV PYTHONPATH=/app
 
 # Install python dependencies
@@ -23,6 +24,10 @@ COPY entrypoint.sh /entrypoint.sh
 RUN chmod +x /entrypoint.sh
 ENTRYPOINT ["/entrypoint.sh"]
 
+# Copy the rest of the project files and define the environment
+COPY ./app /app
+RUN echo ${groupid} > /app/models/.env
+
 # Allow waiting script to be executed
 RUN chmod +x ./wait-for-it.sh