Force SSL on App Engine Flexible Environment Custom Runtime

问题

We're running an instance of Metabase on a App Engine Flexible Custom Runtime with a Dockerfile based on openjdk:8. Currently it allows access on http://[metabase-project].appspot.com/ and https://[metabase-project].appspot.com/. I'd like to force SSL by having all http traffic redirected to https.

The Dockerfile looks something like this:

FROM openjdk:8
ADD https://dl.google.com/cloudsql/cloud_sql_proxy.linux.amd64 ./cloud_sql_proxy
ADD http://downloads.metabase.com/v0.21.1/metabase.jar ./metabase.jar
CMD ./cloud_sql_proxy -instances=$INSTANCE=tcp:$MB_DB_PORT -dir=/cloudsql & java -jar ./metabase.jar

Our app.yaml looks like:

service: metabase
runtime: custom
env: flex

In a normal App Engine app.yaml file, I'd want to add:

handlers:
- url: [something]
  secure: always

But in the custom runtime we don't have access to handlers like this. Is there a way to configure the Flexible runtime to perform the redirect for all traffic?

回答1:

App Engine Flex doesn't support handlers, at all: https://cloud.google.com/appengine/docs/flexible/java/upgrading#appyaml_changes

If you need https:// redirects, you need to do it from within your application. Sorry!

回答2:

Since your app (env: flex in app.yaml) is running behind an nginx reverse proxy which terminates the SSL connection, you need to check the X-FORWARDED-PROTO header which will be either http or https. If it’s http then you can do the redirect.

回答3:

This is what worked for me. In my case using Loopback based NodeJS application running in Cloud Sites App Engine flexible environment.

Create a middleware, for example server/middleware/https-redirect.js with the following code:

/**
* Create a middleware to redirect http requests to https
* @param {Object} options Options
* @returns {Function} The express middleware handler
*/
module.exports = function(options) {
  options = options || {};
  var httpsPort = options.httpsPort || 443;
  return function(req, res, next) {
    if (req.protocol != 'https' && process.env.NODE_ENV !== 'development') {
      var parts = req.get('host').split(':');
      var host = parts[0] || '127.0.0.1';
      return res.redirect('https://' + host + ':' + httpsPort + req.url);
    }
    next();
  };
};

(based on the step 8 in the post http://www.jonxie.com/blog/2014/11/12/setting-up-loopback-to-use-https-and-ssl-certificates/ but modified to use req.protocol instead of req.secure, also will only redirect if not running in development mode)

Modify the file server/server.js to request:

var httpsRedirect = require('./middleware/https-redirect');

An then, after the boot line:

var httpsPort = app.get('https-port');
app.use(httpsRedirect({httpsPort: httpsPort}));
app.set('trust proxy', true)

Setting app.set('trust proxy', true) will let the req.protocol read the X-Forwarded-Proto header.

References:

http://expressjs.com/es/api.html#req.protocol
http://expressjs.com/en/guide/behind-proxies.html
http://www.jonxie.com/blog/2014/11/12/setting-up-loopback-to-use-https-and-ssl-certificates/

回答4:

Late to answer, but I had to struggle a lot in order to do this.

I followed various links which mentioned the following code,

app.use(function(req, res, next) {
  if(!req.secure) {
    return res.redirect(['https://', req.get('Host'), req.url].join(''));
  }
  next();
});

This might work in other cloud vendors.

But in GCP as rightly mentioned by @zengabor, our app will be running behind an nginx reverse proxy which terminates the SSL connection, we need to check the X-FORWARDED-PROTO which can be done by the following code,

app.use(function(req, res, next) {
  if(req.headers['x-forwarded-proto'] && req.headers['x-forwarded-proto'] === "http") {
    return res.redirect(['https://', req.get('Host'), req.url].join(''));
  }
  next();
});

Just adding my answer as after reading @zengabor's code I had to search again on how to achieve it. So above is the readymade code which will work.

来源：https://stackoverflow.com/questions/41944776/force-ssl-on-app-engine-flexible-environment-custom-runtime

标签

google-app-engine

ssl

app-engine-flexible

metabase