Move to gevent from Flask

gevent is a more suitable framework for high performance
throughput and benchmarking. This performs around 2x faster than
Flask with debug=False when tested on loopback with hey on Kube

Signed-off-by: Alex Ellis (VMware) <[email protected]>

Author: alexellis

template/python3-flask/Dockerfile

@@ -7,6 +7,8 @@ RUN apk --no-cache add curl \
     && chmod +x /usr/bin/fwatchdog \
     && apk del curl --no-cache
 
+RUN apk --no-cache add musl-dev gcc make
+
 WORKDIR /root/
 
 COPY requirements.txt   .
@@ -23,6 +25,7 @@ WORKDIR /root/
 COPY function           function
 
 ENV fprocess="python index.py"
+
 ENV cgi_headers="true"
 ENV mode="http"
 ENV upstream_url="http://127.0.0.1:5000"

template/python3-flask/index.py

@@ -3,6 +3,8 @@
 
 from flask import Flask, request
 from function import handler
+#from gevent.wsgi import WSGIServer
+from gevent.pywsgi import WSGIServer
 
 app = Flask(__name__)
 
@@ -12,4 +14,7 @@ def main_route():
     return ret
 
 if __name__ == '__main__':
-    app.run(host='0.0.0.0', port=5000, debug=False)
+    #app.run(host='0.0.0.0', port=5000, debug=False)
+
+    http_server = WSGIServer(('', 5000), app)
+    http_server.serve_forever()

template/python3-flask/requirements.txt

@@ -1,2 +1,3 @@
 flask
+gevent