diff --git a/NEWS.md b/NEWS.md
index 8f235148..26ae1167 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -2,6 +2,7 @@
 -------------------
 
 * Update cartodb-redis dependency to "~0.2.0"
+* Add 'user_from_host' directive to generalize username extraction (#100)
 
 1.5.2 -- 2013-12-05
 -------------------
diff --git a/config/environments/development.js.example b/config/environments/development.js.example
index 03b352e5..97941dd7 100644
--- a/config/environments/development.js.example
+++ b/config/environments/development.js.example
@@ -2,6 +2,9 @@ var config = {
      environment: 'development'
     ,port: 8181
     ,host: '127.0.0.1'
+    // Regular expression pattern to extract username
+    // from hostname. Must have a single grabbing block.
+    ,user_from_host: '^(.*)\\.localhost'
     // Maximum number of connections for one process
     // 128 is a good value with a limit of 1024 open file descriptors
     ,maxConnections:128
diff --git a/config/environments/production.js.example b/config/environments/production.js.example
index db418ca7..e64ad4ea 100644
--- a/config/environments/production.js.example
+++ b/config/environments/production.js.example
@@ -2,6 +2,9 @@ var config = {
     environment: 'production'
     ,port: 8181
     ,host: '127.0.0.1'
+    // Regular expression pattern to extract username
+    // from hostname. Must have a single grabbing block.
+    ,user_from_host: '^(.*)\\.cartodb\\.com$'
     // Maximum number of connections for one process
     // 128 is a good value with a limit of 1024 open file descriptors
     ,maxConnections:128
diff --git a/config/environments/staging.js.example b/config/environments/staging.js.example
index a2918b74..8695ccfc 100644
--- a/config/environments/staging.js.example
+++ b/config/environments/staging.js.example
@@ -2,6 +2,9 @@ var config = {
     environment: 'production'
     ,port: 8181
     ,host: '127.0.0.1'
+    // Regular expression pattern to extract username
+    // from hostname. Must have a single grabbing block.
+    ,user_from_host: '^(.*)\\.cartodb\\.com$'
     // Maximum number of connections for one process
     // 128 is a good value with a limit of 1024 open file descriptors
     ,maxConnections:128
diff --git a/config/environments/test.js.example b/config/environments/test.js.example
index d22fba80..f9bd3929 100644
--- a/config/environments/test.js.example
+++ b/config/environments/test.js.example
@@ -2,6 +2,9 @@ var config = {
      environment: 'test'
     ,port: 8888
     ,host: '127.0.0.1'
+    // Regular expression pattern to extract username
+    // from hostname. Must have a single grabbing block.
+    ,user_from_host: '(.*)'
     // Maximum number of connections for one process
     // 128 is a good value with a limit of 1024 open file descriptors
     ,maxConnections:128
diff --git a/lib/cartodb/server_options.js b/lib/cartodb/server_options.js
index afa8043d..a3366e8f 100644
--- a/lib/cartodb/server_options.js
+++ b/lib/cartodb/server_options.js
@@ -305,8 +305,26 @@ module.exports = function(){
 
 /* X-Cache-Channel generation } */
 
+    me.re_userFromHost = new RegExp(
+      global.environment.user_from_host ||
+      '^([^\\.]+)\\.' // would extract "strk" from "strk.cartodb.com"
+    );
+
     me.userByReq = function(req) {
-        return cartoData.userFromHostname(req.headers.host);
+      var host = req.headers.host;
+      var mat = host.match(this.re_userFromHost);
+      if ( ! mat ) {
+        console.error("ERROR: user pattern '" + this.re_userFromHost
+          + "' does not match hostname '" + host + "'");
+        return;
+      }
+      // console.log("Matches: "); console.dir(mat);
+      if ( ! mat.length === 2 ) {
+        console.error("ERROR: pattern '" + this.re_userFromHost
+          + "' gave unexpected matches against '" + host + "': " + mat);
+        return;
+      }
+      return mat[1];
     }
 
     // Set db authentication parameters to those of the given username