[ruby/rails] Use nginx for Pitchfork (#10203)

Pitchfork relies on a buffering reverse proxy to efficiently deal with
slow clients.

+---------------+-------------------------+-------+
|           name|              branch_name|fortune|
+---------------+-------------------------+-------+
|rails-pitchfork|                   master|   7359|
|rails-pitchfork|    rails/nginx-pitchfork|  12162|
+---------------+-------------------------+-------+

Author: p8

frameworks/Ruby/rails/config/nginx.conf

@@ -0,0 +1,158 @@
+# This is example contains the bare mininum to get nginx going with
+# Unicorn or Rainbows! servers.  Generally these configuration settings
+# are applicable to other HTTP application servers (and not just Ruby
+# ones), so if you have one working well for proxying another app
+# server, feel free to continue using it.
+#
+# The only setting we feel strongly about is the fail_timeout=0
+# directive in the "upstream" block.  max_fails=0 also has the same
+# effect as fail_timeout=0 for current versions of nginx and may be
+# used in its place.
+#
+# Users are strongly encouraged to refer to nginx documentation for more
+# details and search for other example configs.
+
+# you generally only need one nginx worker unless you're serving
+# large amounts of static files which require blocking disk reads
+worker_processes 8;
+
+# # drop privileges, root is needed on most systems for binding to port 80
+# # (or anything < 1024).  Capability-based security may be available for
+# # your system and worth checking out so you won't need to be root to
+# # start nginx to bind on 80
+# user nobody nogroup; # for systems with a "nogroup"
+#user nobody nobody; # for systems with "nobody" as a group instead
+
+# Feel free to change all paths to suite your needs here, of course
+pid /tmp/nginx.pid;
+#error_log /tmp/nginx.error.log;
+error_log stderr error;
+
+events {
+  worker_connections 4096; # increase if you have lots of clients
+  accept_mutex off; # "on" if nginx worker_processes > 1
+  use epoll; # enable for Linux 2.6+
+  # use kqueue; # enable for FreeBSD, OSX
+}
+
+http {
+  # nginx will find this file in the config directory set at nginx build time
+  include /etc/nginx/mime.types;
+
+  # fallback in case we can't determine a type
+  default_type application/octet-stream;
+
+  # click tracking!
+  #access_log /tmp/nginx.access.log combined;
+  access_log off;
+
+  # you generally want to serve static files with nginx since neither
+  # Unicorn nor Rainbows! is optimized for it at the moment
+  sendfile on;
+
+  tcp_nopush on; # off may be better for *some* Comet/long-poll stuff
+  tcp_nodelay off; # on may be better for some Comet/long-poll stuff
+
+  # we haven't checked to see if Rack::Deflate on the app server is
+  # faster or not than doing compression via nginx.  It's easier
+  # to configure it all in one place here for static files and also
+  # to disable gzip for clients who don't get gzip/deflate right.
+  # There are other gzip settings that may be needed used to deal with
+  # bad clients out there, see http://wiki.nginx.org/NginxHttpGzipModule
+  #gzip on;
+  #gzip_http_version 1.0;
+  #gzip_proxied any;
+  #gzip_min_length 500;
+  #gzip_disable "MSIE [1-6]\.";
+  #gzip_types text/plain text/html text/xml text/css
+  #           text/comma-separated-values
+  #           text/javascript application/x-javascript
+  #           application/atom+xml;
+
+  # this can be any application server, not just Unicorn/Rainbows!
+  upstream app_server {
+    # fail_timeout=0 means we always retry an upstream even if it failed
+    # to return a good HTTP response (in case the Unicorn master nukes a
+    # single worker for timing out).
+
+    # for UNIX domain socket setups:
+    server unix:/tmp/.sock fail_timeout=0;
+
+    # for TCP setups, point these to your backend servers
+    # server 192.168.0.7:8080 fail_timeout=0;
+    # server 192.168.0.8:8080 fail_timeout=0;
+    # server 192.168.0.9:8080 fail_timeout=0;
+  }
+
+  server {
+    # enable one of the following if you're on Linux or FreeBSD
+    listen 8080 default deferred; # for Linux
+    # listen 80 default accept_filter=httpready; # for FreeBSD
+
+    # If you have IPv6, you'll likely want to have two separate listeners.
+    # One on IPv4 only (the default), and another on IPv6 only instead
+    # of a single dual-stack listener.  A dual-stack listener will make
+    # for ugly IPv4 addresses in $remote_addr (e.g ":ffff:10.0.0.1"
+    # instead of just "10.0.0.1") and potentially trigger bugs in
+    # some software.
+    # listen [::]:80 ipv6only=on; # deferred or accept_filter recommended
+
+    client_max_body_size 4G;
+    server_name _;
+
+    # ~2 seconds is often enough for most folks to parse HTML/CSS and
+    # retrieve needed images/icons/frames, connections are cheap in
+    # nginx so increasing this is generally safe...
+    keepalive_timeout 10;
+
+    # path for static files
+    root /path/to/app/current/public;
+
+    # Prefer to serve static files directly from nginx to avoid unnecessary
+    # data copies from the application server.
+    #
+    # try_files directive appeared in in nginx 0.7.27 and has stabilized
+    # over time.  Older versions of nginx (e.g. 0.6.x) requires
+    # "if (!-f $request_filename)" which was less efficient:
+    # http://bogomips.org/unicorn.git/tree/examples/nginx.conf?id=v3.3.1#n127
+    try_files $uri/index.html $uri.html $uri @app;
+
+    location @app {
+      # an HTTP header important enough to have its own Wikipedia entry:
+      #   http://en.wikipedia.org/wiki/X-Forwarded-For
+      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+
+      # enable this if you forward HTTPS traffic to unicorn,
+      # this helps Rack set the proper URL scheme for doing redirects:
+      # proxy_set_header X-Forwarded-Proto $scheme;
+
+      # pass the Host: header from the client right along so redirects
+      # can be set properly within the Rack application
+      proxy_set_header Host $http_host;
+
+      # we don't want nginx trying to do something clever with
+      # redirects, we set the Host: header above already.
+      proxy_redirect off;
+
+      # set "proxy_buffering off" *only* for Rainbows! when doing
+      # Comet/long-poll/streaming.  It's also safe to set if you're using
+      # only serving fast clients with Unicorn + nginx, but not slow
+      # clients.  You normally want nginx to buffer responses to slow
+      # clients, even with Rails 3.1 streaming because otherwise a slow
+      # client can become a bottleneck of Unicorn.
+      #
+      # The Rack application may also set "X-Accel-Buffering (yes|no)"
+      # in the response headers do disable/enable buffering on a
+      # per-response basis.
+      # proxy_buffering off;
+
+      proxy_pass http://app_server;
+    }
+
+    # Rails error pages
+    error_page 500 502 503 504 /500.html;
+    location = /500.html {
+      root /path/to/app/current/public;
+    }
+  }
+}

frameworks/Ruby/rails/config/pitchfork.rb

@@ -5,3 +5,5 @@
 num_workers, = auto_tune
 
 worker_processes num_workers
+
+listen "/tmp/.sock", :backlog => 4096

frameworks/Ruby/rails/rails-pitchfork.dockerfile

@@ -12,6 +12,8 @@ RUN apt-get update && \
     apt-get install -y --no-install-recommends libjemalloc2
 ENV LD_PRELOAD=libjemalloc.so.2
 
+RUN apt-get install -yqq nginx
+
 COPY ./Gemfile* /rails/
 
 ENV BUNDLE_FORCE_RUBY_PLATFORM=true
@@ -24,4 +26,5 @@ ENV RAILS_ENV=production_postgresql
 ENV PORT=8080
 ENV REDIS_URL=redis://localhost:6379/0
 CMD service redis-server start && \
+    nginx -c /rails/config/nginx.conf && \
     RACK_ENV=production bundle exec pitchfork -c config/pitchfork.rb