Thursday, June 4, 2015

Moodle with SSL behind Varnish

Ok, after a whole morning working on my moodle server, I finally made it work with SSL while standing behind a Varnish cache server. Things are just as simple as the following steps:


A. Moodle Server Configuration:

1. Moodle's config.php: tell moodle to acknowledge the ssl proxy (the varnish) and provide users access via SSL link
...
$CFG->wwwroot   = 'https://mymoodle.com';
$CFG->sslproxy  = true;
...

2. Nginx's configuration: one important thing here is that we still have to config the nginx to serve moodle at port 80 (without ssl) despite the moodle's configuration

server {
        listen 80;
        root /var/www/moodle;
        index index.php index.html index.htm;
        server_name mymoodle.com;

        access_log   /var/log/nginx/moodle-access.log;
        error_log    /var/log/nginx/moodle-error.log;

        location / {
                try_files $uri $uri/ =404;
        }
        location ~ [^/]\.php(/|$) {
                 # NOTE: You should have "cgi.fix_pathinfo = 0;" in php.ini
                fastcgi_split_path_info  ^(.+\.php)(/.+)$;
                fastcgi_index            index.php;
                fastcgi_pass unix:/var/run/php5-fpm.sock;
                include                  fastcgi_params;

                if (!-e $request_filename) {
                        rewrite ^(.*\.php)(/)(.*)$ $1?file=/$3 last;
                }

                fastcgi_param   PATH_INFO       $fastcgi_path_info;
                fastcgi_param   SCRIPT_FILENAME $document_root$fastcgi_script_name;
        }

}


B. Varnish Server Configuration

1. Varnish's configuration (/etc/varnish/default.vcl):

 backend mymoodle {
        .host = "<moodle server's ip address>";
        .port = "80";
        .connect_timeout = 30s;
        .between_bytes_timeout = 15s;
        .first_byte_timeout = 300s;
 }
sub vcl_recv {

if (req.http.X-Forwarded-Proto == "https" ) {
        set req.http.X-Forwarded-Port = "443";
} else {
        set req.http.X-Forwarded-Port = "80";
        set req.http.X-Forwarded-Proto = "http";
}

if (req.http.host ~ "^(www.)?mymoodle.com$") {
       set req.http.host = "mymoodle.com";
       set req.backend = mymoodle;

...

}

2. nginx's configuration: because Varnish doesn't work with SSL (normally) we have to tell nginx to translate any https request to http (or SSL termination)

server {
    ssl on;
    ssl_certificate /etc/nginx/mycert.crt;
    ssl_certificate_key /etc/nginx/mycert.key;
    listen 443 default ssl;

    access_log /var/log/nginx/secure_server_access.log;
    error_log /var/log/nginx/secure_server_error.log;

    # Proxy any requests to the local varnish instance
    location / {
        proxy_set_header "X-Forwarded-For" $proxy_add_x_forwarded_for;

        proxy_set_header        Host    $host;
        proxy_redirect http:// https://;
        proxy_set_header        X-Real-IP 127.0.0.1;
        proxy_set_header        X-Forwarded-Proto https;

        proxy_pass http://127.0.0.1:80;

        proxy_connect_timeout   5s;
        proxy_read_timeout      300s;
    }

}


This way, only the connections between the users and varnish server are encrypted, everything else (like between Varnish and Moodle server) is normal.

After everything is setup, I can access my moodle server at: https://mymoodle.com or http://mymoodle.com (then when I click the login screen, I will be redirected to https://newmoodle.ssis.edu.vn/login/index.php).

Pretty neat huh?! \m/\m/\m/