Varnish VCL 4 - Com explicações

default.vcl

#Define como linguagem a versao 4.0
vcl 4.0;

# Importa as features standard
import std;

#Importa as features para Balanceamento
import directors;

# Probe serve para fazer um health check dos backends e em caso de falha não encaminha as requisições para o backend com falhas.
probe health {
        # Url de consulta, padrao eh "/"
        # .url = "/";
        # Especifica uma requisicao completa de  HTTP usando multiplas strings
        .request =
          "HEAD / HTTP/1.1"
          "Host: homolog.opac.scielo.org"
          "Connection: close"
          "User-Agent: Varnish Health Probe";
        # Codigo HTTP esperado. padrao eh 200.
        .expected_response = 200;
        # Tempo de TimeOut para o Probe
        .timeout = 3s;
        # Frequencia que o probe faz a checagem
        .interval = 30s;
        # Quantas pesquisas para testar a saude do backend
        .window =5;
        # Se 3 tiverem sucesso eu considero o backend saudevel
        .threshold = 3;
}

backend lb01opac {
    .host = "192.168.1.60";
    .port = "56889";
    .probe = health;
}

backend lb02opac {
    .host = "192.168.1.61";
    .port = "56889";
    .probe = health;
}

sub vcl_init {
    new round_robin_director = directors.round_robin();
    round_robin_director.add_backend(lb01opac);
    round_robin_director.add_backend(lb02opac);
}

sub vcl_recv {
    # Regra de X-Forwarded-For
    if (req.http.x-forwarded-for) {
        set req.http.X-Forwarded-For = req.http.X-Forwarded-For + ", " + client.ip;
    } else {
        set req.http.X-Forwarded-For = client.ip;
    }
    if (req.url ~ "^/admin") {
		return (pass);
    }
# Exemplo de redirect na requisição pelo browser
#    if (req.url ~ "^/set_locale/pt_BR") {
#	return (synth(301, "https://uol.com.br"));
#    }
#    if (req.url ~ "^/set_locale/es") {
#	return (synth(301, "https://cnnespanol.cnn.com/"));
#    }
#    if (req.url ~ "^/set_locale/en") {
#	return (synth(301, "http://edition.cnn.com/"));
#    }
    # Regra geral para fazer cache de requisicoes GET e HEAD
    if (req.method != "GET" &&
        req.method != "HEAD" &&
        req.method != "PUT" &&
        req.method != "POST" &&
        req.method != "TRACE" &&
        req.method != "OPTIONS" &&
        req.method != "DELETE") {
        /* Non-RFC2616 or CONNECT which is weird. */
        return (pipe);
    }
    if (req.method != "GET" && req.method != "HEAD") {
        /* We only deal with GET and HEAD by default */
        return (pass);
    }
return (hash);
}


# FUNCIONA CACHE MAS SEM MUDANÇA DE IDIOMA
sub vcl_backend_response {
## Regras de Bypass
    if (bereq.url ~ "^/admin") {
         return (deliver);
    }
    if (bereq.url ~ "^/set_locale/pt_BR") {
	return (deliver);
    }
    if (bereq.url ~ "^/set_locale/es") {
	return (deliver);
    }
    if (bereq.url ~ "^/set_locale/en") {
	return (deliver);
    }
    unset beresp.http.expires;
    set beresp.http.cache-control = "max-age=900";
    set beresp.ttl = 168h;
    unset beresp.http.Server;
    set beresp.http.Server = "nginx";
    return (deliver);
}

# CACHE DUVIDOSO, MAS FUNCIONA A TROCA DE IDIOMA
# Regras explicadas pelo Juan
#sub vcl_backend_response {
# Regras de Bypass
#    if (bereq.url ~ "^/admin") {
#         return (deliver);
#    }
#    if (beresp.ttl <= 0s ||
#      beresp.http.Set-Cookie ||
#      beresp.http.Surrogate-control ~ "no-store" ||
#      (!beresp.http.Surrogate-Control &&
#        beresp.http.Cache-Control ~ "no-cache|no-store|private") ||
#      beresp.http.Vary == "*") {
#        /*
#        * Mark as "Hit-For-Pass" for the next 2 minutes
#        */
#        set beresp.ttl = 120s;
#        set beresp.uncacheable = true;
#
#    } else {
#        set beresp.grace = 1h;
#/* Remove Expires from backend, it's not long enough */
#        unset beresp.http.expires;
#/* Defina o TTL do client para este objeto */
#        # set beresp.http.cache-control = "max-age=900";
#/* Tempo de retencao de um cache */
#        set beresp.ttl = 168h;
#/* Unset  Apache sends a Server header such as Server: nginx and set other header */
#        unset beresp.http.Server;
#        set beresp.http.Server = "nginx";
#    }
#    return (deliver);
#}


# ESTUDO PARA CONCILIAR CACHE E MUDANCA DE IDIOMA
#sub vcl_backend_response {
# Regras de Bypass
#    if (bereq.url ~ "^/admin") {
#         return (deliver);
#    }
#    if (beresp.ttl <= 0s ||
#      beresp.http.Set-Cookie ||
#      beresp.http.Surrogate-control ~ "no-store" ||
#      (!beresp.http.Surrogate-Control &&
#        beresp.http.Cache-Control ~ "no-cache|no-store|private") ||
#      beresp.http.Vary == "*") {
#        /*
#        * Mark as "Hit-For-Pass" for the next 2 minutes
#        */
#        set beresp.ttl = 120s;
#        set beresp.uncacheable = true;
#    } else
#     if (bereq.url ~ "^/set_locale" && beresp.http.set-cookie){
#          set beresp.ttl = 120s;
#          set beresp.uncacheable = true;
#   	  set beresp.http.X-Burg = "CAI";
#        }
#    set beresp.grace = 1h;
#    unset beresp.http.expires;
#    set beresp.http.cache-control = "max-age=900";
#    set beresp.ttl = 168h;
#    unset beresp.http.Server;
#    set beresp.http.Server = "nginx";
#    #}
#    return (deliver);
#}




# The data on which the hashing will take place
sub vcl_hash {
    hash_data(req.url);
    if (req.http.host) {
        hash_data(req.http.host);
    } else {
        hash_data(server.ip);
    }
    return (lookup);
}

sub vcl_deliver {
    if (obj.hits > 0) {
        set resp.http.X-Cache = "HIT";
      } else {
        set resp.http.X-Cache = "MISS";
      }
# Configuracao de Redirect quando vem resposta do Servidor
    if (resp.status == 302 && req.url ~ "^/set_locale/pt_BR") {
        set resp.http.location = resp.reason;
        set resp.reason = "Moved";
        set resp.http.X-Deliver = "HIT";
#	return (synth(301, "https://uol.com.br"));
#	return (synth(301, "https://homolog.opac.scielo.org/set_locale/pt_BR"));
        return(deliver);
    }
    if (resp.status == 302 && req.url ~ "^/set_locale/es") {
        set resp.http.location = resp.reason;
        set resp.reason = "Moved";
        set resp.http.X-Deliver = "HIT";
#	return (synth(301, "https://cnnespanol.cnn.com/"));
#	return (synth(301, "https://homolog.opac.scielo.org/set_locale/es"));
        return(deliver);
    }
    if (resp.status == 302 && req.url ~ "^/set_locale/en") {
        set resp.http.location = resp.reason;
        set resp.reason = "Moved";
        set resp.http.X-Deliver = "HIT";
#	return (synth(301, "http://edition.cnn.com/"));
#	return (synth(301, "https://homolog.opac.scielo.org/set_locale/en"));
        return(deliver);
    }
#    unset resp.http.X-Powered-By;
    return (deliver);
}
sub vcl_synth {
    if (resp.status == 301) {
        set resp.http.location = resp.reason;
        set resp.reason = "Moved";
        return (deliver);
    }
}