Fastly Service VCL Custom Template - February 2022

main.vcl

sub vcl_recv {
#FASTLY recv

  # Normally, you should consider requests other than GET and HEAD to be uncacheable
  # (to this we add the special FASTLYPURGE method)
  if (req.method != "HEAD" && req.method != "GET" && req.method != "FASTLYPURGE") {
    return(pass);
  }

  return(lookup);
}

sub vcl_fetch {
#FASTLY fetch

  # In the event of a server-failure response from origin, retry once more
  if ((beresp.status == 500 || beresp.status == 503) && req.restarts < 1 && (req.method == "GET" || req.method == "HEAD")) {
    restart;
  }

  # Log the number of restarts for debugging purposes
  if(req.restarts > 0 ) {
    set beresp.http.Fastly-Restarts = req.restarts;
  }

  # If the response is setting a cookie, make sure it is not cached
  if (beresp.http.Set-Cookie) {
    return(pass);
  }

  # By default we set a TTL based on the `Cache-Control` header
  # but we don't parse additional directives like `private` and
  # `no-store`.  Private in particular should be respected at the edge:
  if (beresp.http.Cache-Control ~ "(private|no-store)") {
    return(pass);
  }

  # If the backend response is 500 or 503, then override
  # Surrogate-Control, Cache-Control, and default TTL settings.
  if (beresp.status == 500 || beresp.status == 503) {
    set beresp.ttl = 1s;
    set beresp.stale_if_error = 5s;
    return(deliver);
  }

  # If no TTL has been provided in the response headers, set a default
  if (!beresp.http.Expires && !beresp.http.Surrogate-Control ~ "max-age" && !beresp.http.Cache-Control ~ "(s-maxage|max-age)") {
    set beresp.ttl = 3600s;
  }

  return(deliver);
}

sub vcl_hit {
#FASTLY hit

  return(deliver);
}

sub vcl_miss {
#FASTLY miss
  return(fetch);
}

sub vcl_deliver {
#FASTLY deliver
  return(deliver);
}

sub vcl_error {
#FASTLY error
  return(deliver);
}

sub vcl_pass {
#FASTLY pass
  return(pass);
}

sub vcl_log {
#FASTLY log
}

sub vcl_hash {
  set req.hash += req.url;
  set req.hash += req.http.host;
#FASTLY hash
  return(hash);
}