Configure multiple sites with Varnish

Question

We have a server which needs to serve multiple domains though varnish e.g. example1.com, example2.com and example3.com

Our current .vcl file looks like this:

sub vcl_recv {   set req.http.Host = "example1.com";       lookup; } 

How do I set the correct req.http.Host for the correct incoming request?

Answer 1

You can support multiple frontend domains this way:

 backend example1 {      .host = "backend.example1.com";      .port = "8080";  }  backend example2 {       .host = "backend.example2.com";       .port = "8080";  }  sub vcl_recv {     if (req.http.host == "example1.com") {         #You will need the following line only if your backend has multiple virtual host names         set req.http.host = "backend.example1.com";         set req.backend = example1;         return (lookup);     }     if (req.http.host == "example2.com") {         #You will need the following line only if your backend has multiple virtual host names         set req.http.host = "backend.example2.com";         set req.backend = example2;         return (lookup);     }  } 

Answer 2

I'm using setup similar to Cristian's, but in if clauses I match req.http.host against regular expression:

#for www.example.com or example.com if (req.http.host ~ "^(www\.)?example\.com$") {         set req.backend = example_com;         return (lookup); }  #with any subdomain support if (req.http.host ~ "^(.*\.)?example2\.com$") {         set req.backend = example2_com;         return (lookup); } 

Don't forget to set backends appropriately!