Merge pull request #9 from NREL/long-hostnames

Fix handling of long hostnames

lib/config_reloader/worker.js

@@ -263,6 +263,8 @@ _.extend(Worker.prototype, {
       hosts['*'].hostname = '_';
     }
 
+    var longestHostname = 0;
+
     // Now that we know each of the hosts and each of the URL prefixes those
     // hosts are responsible for, we can assemble the regex for matching the
     // prefixes on each host which we'll then pass to nginx.
@@ -271,10 +273,33 @@ _.extend(Worker.prototype, {
         hostConfig.api_url_prefixes_matcher = '^(' + hostConfig.api_url_prefixes.join('|') + ')';
         delete hostConfig.api_url_prefixes;
       }
+
+      if(hostConfig.hostname.length > longestHostname) {
+        longestHostname = hostConfig.hostname.length;
+      }
     });
 
+    // Choose the nginx host bucket size based on the longest hostname that's
+    // in the system. Try to pick among the nginx default values, since I think
+    // there may be benefits with sticking with these sizes (to align with CPU
+    // cache sizes): http://nginx.org/en/docs/hash.html Max out at 128. We can
+    // revisit this max if needs be.
+    //
+    // For reasons I don't currently understand, a setting of 128 only supports
+    // a hostname 110 characters long. So add in a buffer so that we increase
+    // this setting's length even for shorter hostnames.
+    var hostnameBucketSize = 32;
+    var hostnameBucketBuffer = 18;
+    if(longestHostname >= 32 - hostnameBucketBuffer && longestHostname < 64 - hostnameBucketBuffer) {
+      hostnameBucketSize = 64;
+    } else if(longestHostname >= 64 - hostnameBucketBuffer) {
+      hostnameBucketSize = 128;
+    }
+
     var templateConfig = _.extend({}, config.getAll(), {
       hosts: _.values(hosts),
+
+      _server_names_hash_bucket_size: hostnameBucketSize,
     });
 
     var newContent = this.nginxFrontendTemplate(templateConfig);

templates/etc/nginx/frontend_hosts.conf.hbs

@@ -1,3 +1,5 @@
+server_names_hash_bucket_size {{_server_names_hash_bucket_size}};
+
 {{#each hosts}}
 server {
   listen {{../http_port}}{{#if default}} default_server{{/if}};

test/config/test.yml

@@ -281,6 +281,15 @@ apis:
     url_matches:
       - frontend_prefix: /wildcard-dot-info/
         backend_prefix: /info/
+  - _id: long-frontend-host
+    frontend_host: abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghij
+    backend_host: abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghij
+    servers:
+      - host: 127.0.0.1
+        port: 9444
+    url_matches:
+      - frontend_prefix: /long-host-info/
+        backend_prefix: /info/
   - _id: wildcard-frontend-host
     frontend_host: "*"
     backend_host: localhost

test/integration/proxying.js

@@ -228,6 +228,25 @@ describe('proxying', function() {
         done();
       });
     });
+
+    // I'm not exactly sure why, but when we set server_names_hash_bucket_size
+    // to 128, it actually only allows hostnames 110 characters long. Perhaps
+    // something to investigate or better understand, but in the meantime
+    // documenting current behavior.
+    it('supports hostname lengths up to 110 characters', function(done) {
+      var options = _.merge({}, this.options, {
+        headers: {
+          'Host': 'abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghij',
+        },
+      });
+
+      request.get('http://localhost:9080/long-host-info/', options, function(error, response, body) {
+        response.statusCode.should.eql(200);
+        var data = JSON.parse(body);
+        data.headers.host.length.should.eql(110);
+        done();
+      });
+    });
   });
 
   // Ensure basic HTTP requests of all HTTP methods work with the entire stack