Update docker file

Dockerfile

@@ -1,21 +1,27 @@
 # Use an official Python runtime as a parent image
 FROM python:2.7-slim
 
+ARG PORT
+ENV PORT ${PORT:-8080}
+
+# Define environment variable
+ARG NAME
+ENV NAME ${NAME:-World}
+
 # Set the working directory to /app
 WORKDIR /app
 
-# Copy the current directory contents into the container at /app
-ADD . /app
+ADD install-reqs.sh requirements.txt /app/
 
 # Install any needed packages specified in requirements.txt
-RUN pip install --trusted-host pypi.python.org -r requirements.txt
+# RUN pip install --trusted-host pypi.python.org -r requirements.txt
+RUN bash -c "/app/install-reqs.sh"
 
-# Make port 80 available to the world outside this container
-EXPOSE 80
-
-# Define environment variable
-ENV NAME World
+# Make port available to the world outside this container
+EXPOSE ${PORT}
 
 # Run app.py when the container launches
 CMD ["python", "app.py"]
 
+# Copy the current directory contents into the container at /app
+ADD . /app

app.py

@@ -8,6 +8,12 @@
 
 app = Flask(__name__)
 
+def parse_int(s, val=None):
+ if s.isdigit():
+  return int(s, 10)
+ else:
+  return val
+
 @app.route("/")
 def hello():
     try:
@@ -21,5 +27,5 @@ def hello():
     return html.format(name=os.getenv("NAME", "world"), hostname=socket.gethostname(), visits=visits)
 
 if __name__ == "__main__":
-    app.run(host='0.0.0.0', port=8080)
+    app.run(host='0.0.0.0', port=parse_int(os.getenv("PORT", 8080)))
 

install-reqs.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+set -eo pipefail;
+
+pip install --trusted-host pypi.python.org -r requirements.txt