fix: dockerfile deps and cmd

- The intl package needs some OS deps
- The CMD now correctly starts the server on $PORT

Author: satazor

Dockerfile

@@ -7,11 +7,20 @@ ARG GA_TRACKING_ID
 # Define environment variables
 ENV PORT 3000
 ENV HOST 0.0.0.0
-ENV GA_TRACKING_ID ${GA_TRACKING_ID}
+ENV GA_TRACKING_ID $GA_TRACKING_ID
 
 # Define project dir
 WORKDIR /usr/src/app
 
+# Install OS deps necessary by some packages (e.g.: node-canvas)
+RUN apk add --update --no-cache \
+    make \
+    g++ \
+    jpeg-dev \
+    cairo-dev \
+    giflib-dev \
+    pango-dev
+
 # Install dependencies
 COPY package*.json ./
 RUN npm install
@@ -24,4 +33,4 @@ RUN npm run build
 
 # Expose port and start command
 EXPOSE $PORT
-CMD [ "npm", "start" ]
+CMD npm start -- -p $PORT