When your Graylog instance/cluster is up and running, the next thing you usually want to do is check out our web interface, which offers you great capabilities for searching and analyzing your indexed data and configuring your Graylog environment. Per default you can access it using your browser on http://<graylog-server>:9000/.

Overview

The Graylog web interface was rewritten in JavaScript for 2.0 to be a client-side single-page browser application. This means its code is running solely in your browser, fetching all data via HTTP(S) from the REST API of your Graylog server.

Configuration Options

If our default settings do not work for you, there is a number of options in the Graylog server configuration file which you can change to influence its behavior:

How Does the Web Interface Connect to the Graylog Server?

The web interface is fetching all information it is showing from the REST API of the Graylog server. Therefore it needs to connect to it using HTTP(S). There are several ways how you can define which way the web interface connects to the Graylog server. The URI used by the web interface is determined in this exact order:

• If the HTTP(S) client going to the web interface port sends a X-Graylog-Server-URL header, which contains a valid URL, then this is overriding everything else.

• If http_external_uri is defined in the Graylog configuration file, this is used if the aforementioned header is not set.

• If http_publish_uri is defined in the Graylog configuration file, this is used if the aforementioned http_external_uri is not set.

• If none of the above are defined, http://$http_bind_address is used.

The web interface assets (e.g. the index.html, CSS and JavaScript files) are accessible at the URI root (/ by default) and the REST API endpoints are accessible at the /api path.

Example:

Setting http_bind_address to 10.0.0.1:9000 configures the Graylog server with the following URLs.

• Web interface: http://10.0.0.1:9000/

• REST API: http://10.0.0.1:9000/api/

Browser Compatibility

Graylog strives to provide the best possible experience to everyone, which often means using modern web technology only available in recent browsers while keeping a reasonable compatibility with older and less-capable browsers. For supported browsers, we support the latest version of the browser as well as its previous two releases.

Here are the supported browsers for Graylog along with the operating systems on which each browser is supported:

Making the Web Interface Work with Load Balancers/Proxies

If you want to run a load balancer/reverse proxy in front of Graylog, you need to make sure that:

• The HTTP port of the load balancer/reverse proxy is accessible for clients

• The HTTP address for the Graylog server is properly set so it is resolvable and accessible for the load balancer/reverse proxy.

• If you use SSL, your certificates must be valid and trusted by your clients.

For the configuration use cases below we assume the following:

• Your Graylog server configuration contains http_bind_address = 127.0.0.1:9000

• The hostname for the setup is graylog.example.org

• The IP address for that hostname is 192.168.0.10

Using a Layer 3 Load Balancer (Forwarding TCP Ports)

1. Configure your load balancer to forward connections going to 192.168.0.10:80 to 127.0.0.1:9000.

2. Start the Graylog server as usual.

3. Access the web interface on http://graylog.example.org.

4. Read up on using HTTPS.

NGINX

Proxy web interface and API traffic using HTTP:

server
{
    listen 80 default_server;
    listen [::]:80 default_server ipv6only=on;
    server_name graylog.example.org;

    location / {
      proxy_set_header Host $http_host;
      proxy_set_header X-Forwarded-Host $host;
      proxy_set_header X-Forwarded-Server $host;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header X-Graylog-Server-URL http://$server_name/;
      proxy_pass       http://127.0.0.1:9000;
    }
}

NGINX can be used for SSL Termination, you would only need to modify the server listen directive and add all Information about your certificate.

If you are deploying multiple Graylog Servers you can use HTTPS/SSL to connect to the Graylog Servers (read Using HTTPS) and use HTTPS/SSL on NGINX. The configuration for TLS certificates, keys and ciphers is omitted from the sample config for brevity’s sake.

Proxy Web Interface and API Traffic Using HTTPS (TLS)

server
{
    listen      443 ssl http2;
    server_name graylog.example.org;
    # <- your SSL Settings here!

    location /
    {
      proxy_set_header Host $http_host;
      proxy_set_header X-Forwarded-Host $host;
      proxy_set_header X-Forwarded-Server $host;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header X-Graylog-Server-URL https://$server_name/;
      proxy_pass       http://127.0.0.1:9000;
    }
}

If you want to serve several different applications under one domain name, you can also serve the Graylog web interface using a path prefix.

Proxy Web Interface and API Traffic under a Path Prefix Using HTTP

server
{
    listen 80 default_server;
    listen [::]:80 default_server ipv6only=on;
    server_name applications.example.org;

    location /graylog/
    {
      proxy_set_header Host $http_host;
      proxy_set_header X-Forwarded-Host $host;
      proxy_set_header X-Forwarded-Server $host;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header X-Graylog-Server-URL http://$server_name/graylog/;
      rewrite          ^/graylog/(.*)$  /$1  break;
      proxy_pass       http://127.0.0.1:9000;
    }
}

This makes your Graylog setup available under the following URLs:

• Web interface: http://applications.example.org/graylog/

• REST API: http://applications.example.org/graylog/api/

Apache HTTPD 2.X

Proxy Web Interface and API Traffic Using HTTP

<VirtualHost *:80>
    ServerName graylog.example.org
    ProxyRequests Off
    <Proxy *>
        Order deny,allow
        Allow from all
    </Proxy>

    <Location />
        RequestHeader set X-Graylog-Server-URL "http://graylog.example.org/"
        ProxyPass http://127.0.0.1:9000/
        ProxyPassReverse http://127.0.0.1:9000/
    </Location>

</VirtualHost>

Proxy Web Interface and API Traffic Using HTTPS (TLS)

<VirtualHost *:443>
    ServerName graylog.example.org
    ProxyRequests Off
    SSLEngine on
    # <- your SSL Settings here!

    <Proxy *>
        Order deny,allow
        Allow from all
    </Proxy>

    <Location />
        RequestHeader set X-Graylog-Server-URL "https://graylog.example.org/"
        ProxyPass http://127.0.0.1:9000/
        ProxyPassReverse http://127.0.0.1:9000/
    </Location>

</VirtualHost>

HAProxy 1.6

Proxy Web Interface and API Traffic Using HTTP

frontend http
    bind 0.0.0.0:80

    option forwardfor
    http-request add-header X-Forwarded-Host %[req.hdr(host)]
    http-request add-header X-Forwarded-Server %[req.hdr(host)]
    http-request add-header X-Forwarded-Port %[dst_port]
    acl is_graylog hdr_dom(host) -i -m str graylog.example.org
    use_backend     graylog if is_graylog

backend graylog
    description     The Graylog Web backend.
    http-request set-header X-Graylog-Server-URL http://graylog.example.org/
    use-server graylog_1
    server graylog_1 127.0.0.1:9000 maxconn 20 check

Multiple Backends (Roundrobin) with Health-Check (using HTTP)

frontend graylog_http
    bind *:80
    option forwardfor
    http-request add-header X-Forwarded-Host %[req.hdr(host)]
    http-request add-header X-Forwarded-Server %[req.hdr(host)]
    http-request add-header X-Forwarded-Port %[dst_port]
    acl is_graylog hdr_dom(host) -i -m str graylog.example.org
    use_backend     graylog

backend graylog
    description     The Graylog Web backend.
    balance roundrobin
    option httpchk HEAD /api/system/lbstatus
    http-request set-header X-Graylog-Server-URL http://graylog.example.org/
    server graylog1 192.168.0.10:9000 maxconn 20 check
    server graylog2 192.168.0.11:9000 maxconn 20 check
    server graylog3 192.168.0.12:9000 maxconn 20 check