docker: use uwsgi to run application by default

* (addresses reanahub/reana-server#48).

Dockerfile

@@ -20,7 +20,6 @@
 
 FROM python:3.6
 
-ENV TERM=xterm
 RUN apt-get update && \
     apt-get install -y vim-tiny && \
     pip install --upgrade pip
@@ -38,5 +37,17 @@ RUN if [ "${DEBUG}" = "true" ]; then pip install -r requirements-dev.txt; pip in
 RUN adduser --uid 1000 --disabled-password --gecos '' reanauser && \
     chown -R reanauser:reanauser /code
 USER reanauser
+
+ARG UWSGI_PROCESSES=2
+ENV UWSGI_PROCESSES ${UWSGI_PROCESSES:-2}
+ARG UWSGI_THREADS=2
+ENV UWSGI_THREADS ${UWSGI_THREADS:-2}
+ENV TERM=xterm
+
 EXPOSE 5000
-CMD ["python", "reana_job_controller/app.py"]
+
+CMD uwsgi --module reana_job_controller.app:app \
+    --http-socket 0.0.0.0:5000 --master \
+    --processes ${UWSGI_PROCESSES} \
+    --threads ${UWSGI_THREADS} \
+    --stats /tmp/stats.socket

reana_job_controller/app.py

@@ -369,22 +369,21 @@ def get_openapi_spec():
     return jsonify(app.config['OPENAPI_SPEC'])
 
 
-if __name__ == '__main__':
-    logging.basicConfig(
-        level=logging.DEBUG,
-        format='%(asctime)s - %(threadName)s - %(levelname)s: %(message)s'
-    )
+app.config.from_object('reana_job_controller.config')
 
-    app.config.from_object('config')
+with app.app_context():
+    app.config['OPENAPI_SPEC'] = build_openapi_spec()
+    app.config['KUBERNETES_CLIENT'] = create_api_client()
 
-    with app.app_context():
-        app.config['OPENAPI_SPEC'] = build_openapi_spec()
-        app.config['KUBERNETES_CLIENT'] = create_api_client()
+job_event_reader_thread = threading.Thread(target=watch_jobs,
+                                            args=(JOB_DB,))
 
-    job_event_reader_thread = threading.Thread(target=watch_jobs,
-                                               args=(JOB_DB,))
+job_event_reader_thread.start()
 
-    job_event_reader_thread.start()
+logging.basicConfig(
+    level=logging.DEBUG,
+    format='%(asctime)s - %(threadName)s - %(levelname)s: %(message)s'
+)
 
-    app.run(debug=True, port=5000,
-            host='0.0.0.0')
+if __name__ == '__main__':
+    app.run(host='0.0.0.0')

setup.py

@@ -70,6 +70,9 @@
     'kubernetes>=6.0.0',
     'marshmallow>=2.13',
     'reana-commons>=0.1.0',
+    'uwsgi-tools>=1.1.1',
+    'uWSGI>=2.0.17',
+    'uwsgitop>=0.10',
 ]
 
 packages = find_packages()