Varnish cache static

default.vcl

vcl 4.0;
import directors;
import dynamic;

# Probe for sharding node
probe health_check_probe {
  .url = "/health";
  .interval = 5s;
  .timeout = 1s;
  .window = 5;
  .threshold = 3;
  .initial = 3;
}

# Probe for backend api server
probe api_probe {
  .expected_response = 400;
  .interval = 5s;
  .timeout = 1s;
  .window = 5;
  .threshold = 3;
  .initial = 3;
}

# You can add multiple sharding node
backend node01 {
  .host = "node01.domain.lan";
  .port = "6081";
  .probe = health_check_probe;
}
backend node02 {
  .host = "node02.domain.lan";
  .port = "6081";
  .probe = health_check_probe;
}

acl ipv4_only { "0.0.0.0"/0; }

sub vcl_init {
  new cluster = directors.hash();
  cluster.add_backend(node01, 1);
  cluster.add_backend(node02, 1);
  new api_1 = dynamic.director(
    port = "80",
    probe = api_probe,
    ttl = 2m,
    whitelist = ipv4_only
  );
  new api_2 = dynamic.director(
    port = "80",
    probe = api_probe,
    ttl = 2m,
    whitelist = ipv4_only
  );
}

sub vcl_recv {
  # Happens before we check if we have this in cache already.
  # Typically you clean up the request here, removing cookies you
  # don't need, rewriting the request, etc.
  if (req.url ~ "^/health") {
    return(synth(750));
  }
  # SHARDING
  set req.backend_hint = cluster.backend(req.url);
  set req.http.X-shard = req.backend_hint;
  if (
    req.http.X-shard == server.identity
  ) {
    if ( req.url ~ "^/path_1" && req.method == "GET" ) {
      # Strip the cookies
      unset req.http.cookie;
      set req.backend_hint = api_1.backend("api1.domain.com");
      return(hash);
    } elif ( req.url ~ "^/path_2" && req.method == "GET" ) {
      # Strip the cookies
      unset req.http.cookie;
      set req.backend_hint = api_2.backend("api2.domain.com");
      return(hash);
    } else {
      # Return a 404 if varnish don't fetch it
      return(synth(404));
    }
  } else {
    set req.http.X-Varnish-Cache = "pass";
    return(pass);
  } 
}


#################
# Backend Fetch #
#################
sub vcl_backend_fetch {
  # Add Host header
  if ( bereq.url ~ "^/path_1" && bereq.method == "GET" ) {
    set bereq.http.host = "api1.domain.com";
  } elif ( bereq.url ~ "^/path_2" && bereq.method == "GET" ) {
    set bereq.http.host = "api2.domain.com";
  }
  return (fetch);
 }
 
 sub vcl_backend_response {
  # Happens after we have read the response headers from the backend.
  # Here you clean the response headers, removing silly Set-Cookie
  # headers and other mistakes your backend does.
  if (
    bereq.url ~ "^/path_1" ||
    bereq.url ~ "^/path_2"
  ){
    # time-to-live 30 days
    set beresp.ttl = 30d;
    unset beresp.http.set-cookie;
    unset beresp.http.Pragma;
    unset beresp.http.Expires;
  }
  # don’t cache redirects and errors
  if (beresp.status >= 300) {
    set beresp.uncacheable = true;
    set beresp.ttl = 30s;
    return (deliver);
  }
  return (deliver);
}

#################
#   Delivery    #
#################
sub vcl_deliver {
  # Happens when we have all the pieces we need, and are about to send the
  # response to the client.
  # You can do accounting or modifying the final object here.
  unset resp.http.Server;
  unset resp.http.Via;
  unset resp.http.X-Varnish;
  unset resp.http.X-Served-By;
  unset resp.http.ETag;
  unset resp.http.Age;
  unset resp.http.X-NLP-IRT;
  return(deliver);
}

sub vcl_synth {
  if (resp.status == 750) {
    # Set a status the client will understand
    set resp.status = 200;
    # Create our synthetic response
    synthetic("OK");
    return(deliver);
  }
}