Site to Site and Reverse Proxy Examples

1. Client1 initiates Site-to-Site protocol, the request is routed to one of upstream NiFi nodes. The NiFi node computes Site-to-Site port for RAW. By the routing rule 'example1' in nifi.properties shown below, port 10443 is returned.

2. Client1 asks peers to 'nifi.example.com:10443', the request is routed to 'nifi0:8081'. The NiFi node computes available peers, by 'example1' routing rule, 'nifi0:8081' is converted to 'nifi0.example.com:10443', so are nifi1 and nifi2. As a result, 'nifi0.example.com:10443', 'nifi1.example.com:10443' and 'nifi2.example.com:10443' are returned.

3. Client1 decides to use 'nifi2.example.com:10443' for further communication.

4. On the other hand, Client2 has two URIs for Site-to-Site bootstrap URIs, and initiates the protocol using one of them. The 'example1' routing does not match this for this request, and port 8081 is returned.

5. Client2 asks peers from 'nifi1:8081'. The 'example1' does not match, so the original 'nifi0:8081', 'nifi1:8081' and 'nifi2:8081' are returned as they are.

6. Client2 decides to use 'nifi2:8081' for further communication.

Routing rule 'example1' is defined in nifi.properties (all node has the same routing configuration):

# S2S Routing for RAW, using server name to node
nifi.remote.route.raw.example1.when=\
${X-ProxyHost:equals('nifi.example.com'):or(\
${s2s.source.hostname:equals('nifi.example.com'):or(\
${s2s.source.hostname:equals('192.168.99.100')})})}
nifi.remote.route.raw.example1.hostname=${s2s.target.hostname}.example.com
nifi.remote.route.raw.example1.port=10443
nifi.remote.route.raw.example1.secure=true

nginx.conf

http {

    upstream nifi {
        server nifi0:8443;
        server nifi1:8443;
        server nifi2:8443;
    }

    # Use dnsmasq so that hostnames such as 'nifi0' can be resolved by /etc/hosts
    resolver 127.0.0.1;

    server {
        listen 443 ssl;
        server_name nifi.example.com;
        ssl_certificate /etc/nginx/nginx.crt;
        ssl_certificate_key /etc/nginx/nginx.key;

        proxy_ssl_certificate /etc/nginx/nginx.crt;
        proxy_ssl_certificate_key /etc/nginx/nginx.key;
        proxy_ssl_trusted_certificate /etc/nginx/nifi-cert.pem;

        location / {
            proxy_pass https://nifi;
            proxy_set_header X-ProxyScheme https;
            proxy_set_header X-ProxyHost nginx.example.com;
            proxy_set_header X-ProxyPort 17590;
            proxy_set_header X-ProxyContextPath /;
            proxy_set_header X-ProxiedEntitiesChain $ssl_client_s_dn;
        }
    }
}

stream {

    map $ssl_preread_server_name $nifi {
        nifi0.example.com nifi0;
        nifi1.example.com nifi1;
        nifi2.example.com nifi2;
        default nifi0;
    }

    resolver 127.0.0.1;

    server {
        listen 10443;
        proxy_pass $nifi:8081;
    }
}

The 'example2' routing maps original host names (nifi0, 1 and 2) to different proxy ports (10443, 10444 and 10445) using 'equals and 'ifElse' expressions.

nifi.properties (all node has the same routing configuration)

# S2S Routing for RAW, using port number to node
nifi.remote.route.raw.example2.when=\
${X-ProxyHost:equals('nifi.example.com'):or(\
${s2s.source.hostname:equals('nifi.example.com'):or(\
${s2s.source.hostname:equals('192.168.99.100')})})}
nifi.remote.route.raw.example2.hostname=nifi.example.com
nifi.remote.route.raw.example2.port=\
${s2s.target.hostname:equals('nifi0'):ifElse('10443',\
${s2s.target.hostname:equals('nifi1'):ifElse('10444',\
${s2s.target.hostname:equals('nifi2'):ifElse('10445',\
'undefined')})})}
nifi.remote.route.raw.example2.secure=true

nginx.conf

http {
    # Same as example 1.
}

stream {

    map $ssl_preread_server_name $nifi {
        nifi0.example.com nifi0;
        nifi1.example.com nifi1;
        nifi2.example.com nifi2;
        default nifi0;
    }

    resolver 127.0.0.1;

    server {
        listen 10443;
        proxy_pass nifi0:8081;
    }
    server {
        listen 10444;
        proxy_pass nifi1:8081;
    }
    server {
        listen 10445;
        proxy_pass nifi2:8081;
    }
}

nifi.properties (all node has the same routing configuration)

# S2S Routing for HTTP
nifi.remote.route.http.example3.when=${X-ProxyHost:contains('.example.com')}
nifi.remote.route.http.example3.hostname=${s2s.target.hostname}.example.com
nifi.remote.route.http.example3.port=443
nifi.remote.route.http.example3.secure=true

nginx.conf

http {
    upstream nifi_cluster {
        server nifi0:8443;
        server nifi1:8443;
        server nifi2:8443;
    }

    # If target node is not specified, use one from cluster.
    map $http_host $nifi {
        nifi0.example.com:443 "nifi0:8443";
        nifi1.example.com:443 "nifi1:8443";
        nifi2.example.com:443 "nifi2:8443";
        default "nifi_cluster";
    }

    resolver 127.0.0.1;

    server {
        listen 443 ssl;
        server_name ~^(.+\.example\.com)$;
        ssl_certificate /etc/nginx/nginx.crt;
        ssl_certificate_key /etc/nginx/nginx.key;

        proxy_ssl_certificate /etc/nginx/nginx.crt;
        proxy_ssl_certificate_key /etc/nginx/nginx.key;
        proxy_ssl_trusted_certificate /etc/nginx/nifi-cert.pem;

        location / {
            proxy_pass https://$nifi;
            proxy_set_header X-ProxyScheme https;
            proxy_set_header X-ProxyHost $1;
            proxy_set_header X-ProxyPort 443;
            proxy_set_header X-ProxyContextPath /;
            proxy_set_header X-ProxiedEntitiesChain $ssl_client_s_dn;
        }
    }
}