router-nginx.conf.erb

user  root root;
worker_processes  1;

error_log <%= node[:nginx][:log_home] %>/nginx_router_error.log debug;
pid        /var/run/nginx_router.pid;

events {
    worker_connections  <%= node[:nginx][:worker_connections] %>;
    use epoll;
    # multi_accept on;
}

http {
  include       mime.types;
  default_type  text/html;
  server_tokens off;

  log_format main  '$host - [$time_local] '
                   '"$request" $status $bytes_sent '
                   '"$http_referer" "$http_user_agent" '
                   '$remote_addr response_time:$upstream_response_time app_id:$app_id';

  access_log   <%= node[:nginx][:log_home] %>/nginx_router_main_access.log main;

  sendfile             on;
  tcp_nopush           on;
  tcp_nodelay          on;

  keepalive_timeout  75 20;

  gzip                 on;
  gzip_min_length      1250;
  gzip_buffers         16 8k;
  gzip_comp_level      2;
  gzip_proxied         any;
  gzip_types           text/plain text/css application/javascript application/x-javascript text/xml application/xml application/xml+rss text/javascript;
  gzip_vary            on;
  gzip_disable         "MSIE [1-6]\.(?!.*SV1)";

  client_max_body_size 256M;

  lua_package_path "<%= node[:lua][:module_path] %>/?.lua;;";
  lua_package_cpath "<%= node[:lua][:module_path] %>/?.so;;";

  upstream router_status {
    server <%= node[:nginx][:uls_ip] %>:<%= node[:nginx][:uls_port] %>;
  }

  server {
    listen       80;
    server_name  _;
    server_name_in_redirect off;

    #TODO: how to make this internal location totally transparent to outside
    location = /vcapuls {
      internal;
      # We should use rewrite_by_lua to scrub subrequest headers
      # as uls doesn't care those headers at all.
      # Given there are some exceptions to clear some headers,
      # we just leave them as is.

      proxy_pass http://unix:/tmp/router.sock:/;
    }

    location / {
      access_log   <%= node[:nginx][:log_home] %>/nginx_router_access.log main;
      proxy_buffering             off;
      proxy_set_header            Host $host;
      proxy_set_header            X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_redirect              off;
      proxy_connect_timeout       10;
      proxy_send_timeout          120;
      proxy_read_timeout          120;

      set $health_monitor '';
      set $app_id 0;
      if ($http_user_agent = "HTTP-Monitor/1.1") {
        set $health_monitor T;
      }
      if ($http_host = "") {
        set $health_monitor "${health_monitor}T";
      }
      if ($health_monitor = TT) {
        # Trigger a subrequest to sync the latest few stats of the worker to uls,
        # if we have multiple workers, there will be still few stats not synced for
        # the workers which don't get this monitor request.
        access_by_lua '
          local uls = require ("uls")

          ngx.log(ngx.DEBUG, "monitor trigger stats syncup")

          local req = uls.generate_stats_request()

          -- generate one subrequest to uls to update stats
          ngx.location.capture(
            "/vcapuls", { body = req }
          )
        ';

        more_set_input_headers "Authorization: Basic <%= Base64.encode64("#{node[:nginx][:status_user]}:#{node[:nginx][:status_passwd]}").strip %>";
        rewrite ^.*$ /healthz break;
        proxy_pass                 http://router_status;
      }

      # We intend to have one "if" block to avoid the above monitor location
      # to twist with below upstream locator server handling.
      # ("if" block effectively creates a nested location and will inherit
      # all the rewrite/access phase handlers of outer location)
      if ($health_monitor != TT) {
        # The following variables are used by lua module code.
        # DO NOT remove or rename any of them!
        set $backend_addr ''; # Backend server address returned from uls for this request
        set $uls_req_tags ''; # Request tags returned from uls for this request to catalog statistics
        set $router_ip '';
        set $timestamp 0;
        set $trace '';
        set $sticky '';

        access_by_lua '
          local uls = require ("uls")

          uls.pre_process_subrequest(ngx, "<%= node[:router][:trace_key] %>")

          local req = uls.generate_uls_request(ngx)

          -- generate one subrequest to uls for querying
          local res = ngx.location.capture(
            "/vcapuls", { body = req }
          )

          uls.post_process_subrequest(ngx, res)
        ';

        proxy_pass http://$backend_addr;

        # Handling response from backend servers
        header_filter_by_lua '
          local uls = require ("uls")

          uls.post_process_response(ngx)
        ';
      }
    }
  }
}