Rails with Puma, getting routes and connections right

tescher

At the browser now I am getting "502 Bad Gateway" from nginx. I have a feeling puma is not configured with nginx correctly. I don't see where my nginx.conf is even accessible.

sean

Our rails installer is a bit broken at the moment, I’ll be working on it later this evening. Sorry about that!

tescher

@sean OK thanks. It seems to a be a routing thing. It is failing not even locating /favicon on the first request.

digitalmoksha

I was at the same point. Puma is not really meant to be serving static assets. You still need a nginx server in front of it. So just like we do for passenger, we need to run our own nginx (proxied from the main nginx server) that then talks to puma.

I haven't setup the extra nginx server yet. I was actually wondering if we could use the system one at /usr/sbin/nginx with our own configuration file. That would be a nice setup because then any security patches the system one gets, you would get as well.

@sean also posted a tutorial on getting nginx/passenger setup like we have at WebFaction (https://community.opalstack.com/d/151-howto-install-rails-running-on-nginxpassenger-on-opalstack). I'm hoping to test that out tonight.

tescher

digitalmoksha Would you recommend going back to Passenger/Nginx, or try to get Puma/Nginx working for a fairly complex Rails app?

sean

digitalmoksha Puma is not really meant to be serving static assets. You still need a nginx server in front of it.

Our recommendation for any backend server is to use a static app (or the equivalent symlink type) for your static assets. That way they'll be served from our frontend, so its not hitting any of your RAM allowance and your backend server has less work to do and should be able to serve your app requests more efficiently.

The downside is that you lose control over the nginx config, eg cache options etc, but we plan to bring some of those options into the dashboard UI at some point.

digitalmoksha

tescher I think it depends on how much time you have. I would like to move to puma, but you have to be sure you're app is thread safe, or don't use threads in puma, only workers. Since I haven't tested at all with puma, I'm really hesitant right now.

I have several sites/accounts I need to get migrated, so I think it's going to be quicker for me to stick with Passenger for the migration (reduce the number of variables) and then play with trying to get puma to work after all the other work is done 😬

digitalmoksha

And so far I'm liking the ability to install apps under different users. For example, I can keep my Rails app under a specific user (so that the GEM_HOME, etc, can be targeted to that app), and then install other static sites or whatever under my normal account. I sometimes run a couple Rails app for a customer, so it's nice to be able to separate them out.

klynton

That's great to hear! We hoped people would like it as much as we did.

tescher

@sean I've bailed on Puma and went with your Passenger tutorial and got that to work. So you can ignore my outstanding support request on the Puma issues

sean

tescher OK, thanks for letting me know! Really sorry that the puma install is causing problems. I'm trying to iron all of that out this morning but if it continues to be a problem we may switch our default install over to nginx+passenger.

digitalmoksha

sean Our recommendation for any backend server is to use a static app (or the equivalent symlink type) for your static assets.

I haven't tried that yet, but that might work. But for at least 3 sites I have, I need to be able to set various nginx values. For example:

        location / {
          client_max_body_size    500m;
          client_body_buffer_size 128K;
          client_body_temp_path   /home/myuser/tmp/client_body_temp;

          proxy_read_timeout      600;
          proxy_connect_timeout   600;
          proxy_send_timeout      600;
          send_timeout            600;
        }

        #--- set the cache headers properly for rails assets
        location ~ ^/assets/ {
          expires 1y;
          add_header Cache-Control public;

          add_header ETag "";
          break;
        }

        #--- for serving the protected_assets
        #    http://airbladesoftware.com/notes/rails-nginx-x-accel-mapping
        #    http://stackoverflow.com/questions/6237016/message-x-accel-mapping-header-missing-in-nginx-error-log
        passenger_env_var HTTP_X_ACCEL_MAPPING "/home/myuser/apps/appname/myproject/releases/\d{14}/protected_assets/=/protected_assets/";
        passenger_pass_header X-Accel-Redirect;
        location /protected_assets/ {
          internal;
          alias /home/myuser/apps/appname/myproject/current/protected_assets/;
        }

But I like the idea of using the beefy frontend nginx server when possible.

sean

We've just rolled out an update to the Rails installer and docs, details available here: https://community.opalstack.com/d/141-problem-launching-rails-application/5