Simple Varnish Config

 1/*
 2*
 3* First, set up a backend to answer the request if there's not a cache hit.
 4*
 5*/
 6backend default {
 7
 8    # Set a host.
 9    .host = "192.168.1.100";
10
11    # Set a port. 80 is normal Web traffic.
12    .port = "8000";
13}
14/*
15*
16* Next, configure the "receive" subroutine.
17*
18*/
19sub vcl_recv {
20    
21    # Use the backend we set up above to answer the request if it's not cached.
22    set req.backend = default;
23    
24    # Pass the request along to lookup to see if it's in the cache.    
25    return(lookup);
26}
27/*
28*
29* Next, let's set up the subroutine to deal with cache misses.
30*
31*/
32sub vcl_miss {
33    
34    # We're not doing anything fancy. Just pass the request along to the
35    # subroutine which will fetch something from the backend.
36    return(fetch);
37}
38/*
39*
40* Now, let's set up a subroutine to deal with cache hits.
41*
42*/
43sub vcl_hit {
44    
45    # Again, nothing fancy. Just pass the request along to the subroutine
46    # which will deliver a result from the cache.
47    return(deliver);
48}
49/*
50*
51* This is the subroutine which will fetch a response from the backend.
52* It's pretty fancy because this is where the basic logic for caching is set.
53*
54*/
55sub vcl_fetch {
56
57    # Get the response. Set the cache lifetime of the response to 1 hour.
58    set beresp.ttl = 1h;
59
60    # Indicate that this response is cacheable. This is important.
61    set beresp.http.X-Cacheable = "YES";
62    
63    # Some backends *cough* Django *cough* will assign a Vary header for
64    # each User-Agent which visits the site. Varnish will store a separate
65    # copy of the page in the cache for each instance of the Vary header --
66    # one for each User-Agent which visits the site. This is bad. So we're
67    # going to strip away the Vary header.
68    unset beresp.http.Vary;
69    
70    # Now pass this backend response along to the cache to be stored and served.
71    return(deliver);
72}
73/*
74*
75* Finally, let's set up a subroutine which will deliver a response to the client.
76*
77*/
78sub vcl_deliver {
79    
80    # Nothing fancy. Just deliver the goods.
81    # Note: Both cache hits and cache misses will use this subroutine.
82    return(deliver);
83}