Networked Proxy (nproxy)

nsdci/dcicommon/nproxy.c

Introduction

The Networked Proxy API (nproxy) is used to send scripts or commands to remote servers for execution. The result is sent back to the client.

Additional Reading: rpc

TCL API

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nproxy.send

Used to send scripts or commands to a named nproxy. See the "Configuration" section for more information.

nproxy.send server script ?timeout?

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nproxy.debug

Used to retrieve the current debug value, or to set a new debug value.

nt.proxy ?boolean?

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Configuration

Server:

    ns_section "ns/server/$server/modules"
        ns_param nssock nssock.so
        ns_param dci dci.so

    ns_section "ns/server/$server/module/nssock"
        ns_param hostname $hostName
        ns_param address $address
        ns_param port $httpPort

    ns_section "ns/server/$server/module/dci/rpc/server/nproxy"
        ns_param http 1

    ns_section "ns/server/$server/module/dci/rpc/server/nproxy/acl"
        ns_param allow 127.0.0.1

    ns_section "ns/server/$server/module/dci/nproxy"
        ns_param debug 1

    ns_section "ns/server/$server/module/dci/nproxy/servers"
        ns_param $nproxyServerName $nproxyServerName

    ns_section "ns/server/$server/module/dci/nproxy/server/$nproxyServerName"
        ns_param handshakeName $nproxyServerName

    ns_section "ns/server/$server/module/dci/nproxy/server/$nproxyServerName/clients"
        # This section has no params but is required.
        # Legacy client list before HTTP RPC.
        # See the rpc/server acl section above. 

Client:

    ns_section "ns/server/$server/module/dci/rpc/client/nproxy:${$nproxyServerName}"
        ns_param address $nproxyServerAddress
        ns_param port $nproxyServerPort
        ns_param httpkeepalive true
        ns_param httpnumconnections 1

    ns_section "ns/server/$server/module/dci/nproxy"
        ns_param debug 1

    ns_section "ns/server/$server/module/dci/nproxy/clients"
        ns_param $nproxyServerName $nproxyServerName

    ns_section "ns/server/$server/module/dci/nproxy/client/$nproxyServerName"
        ns_param timeout 1

Usage

Use the frontend Control Port to send a command to the tool server (See Topology for more information):

    % telnet 127.0.0.1 9900
    Trying 127.0.0.1...
    Connected to localhost.
    Escape character is '^]'.
    login: 
    Password: 

    Welcome to frontend running at /usr/local/aolserver/bin/nsd (pid 7893)
    AOLserver/4.5.0 (aolserver4_5) for osx built on Jan  4 2007 at 17:11:28
    CVS Tag: $Name:  $
    frontend:nscp 1> nproxy.send tool "expr 2 + 2"
    4
    frontend:nscp 2> 

If you tail the tool server log you will see the following notice:

    [08/Jan/2007:15:28:54][7884.25210880][-conn:0-] Notice: eval: 0 expr 2 + 2 ...

The tool server accepted the request and evaluated the script. The result was sent back to the frontend server and was seen in the frontend AOLserver Control Port. Send a log notice to the tool server (See Topology for more information):

    frontend:nscp 2> nproxy.send tool {ns_log notice "Sent this from the frontend server."}

    frontend:nscp 3> exit

    Goodbye!
    Connection closed by foreign host.

There is no returned result for a log notice. But if you look in the tool server log you will see the evaluation notice as well as the result of the script:

    [08/Jan/2007:15:30:08][7884.25210880][-conn:0-] Notice: eval: 0 ns_log notice "Sent this from the fronte ...
    [08/Jan/2007:15:30:08][7884.25210880][-conn:0-] Notice: Sent this from the frontend server.