Gateway connection is a way to communicate between nodes which don't have possibility to create direct connection. Gateway connection is created with help of gateway nodes, each of those has two connections and redirect all data between them. For example it is possible to create gateway connection from OpenAPI client to Network agent through KSC Server as a gateway node; in such case OpenAPI client may make OpenAPI calls to Network agent. With help of gateway connections OpenAPI client may connect to Slave servers, Network agents and components on them. Multi-node gateway connections are also supported, so gateway connections such as OpenAPIClient->MasterServer->SlaveServer->NetworkAgent are possible.

Gateway connections may be created using GatewayConnection interface. The general scheme to create a gateway connection is following:

Obtain gateway node locations and build locations list. Gateway node location as an opaque KLPAR::Params container retrieved using helper interfaces, such as CgwHelper.
Call GatewayConnection.PrepareGatewayConnection method to create gateway connection, and receive one-time authentication key.
Create new OpenAPI connection or session to same KSC server using KSCGW authentication scheme with provided one-time authentication key.

If 'login' method was used for authentication, then after successful authentication current connection may be used to make OpenAPI calls to target.
If Session.StartSession was called for authentication, then all calls within created session will be routed to target host.

To connect to Network Agent obtain its location using CgwHelper.GetNagentLocation method, and build location list as an array of one element containing received location.
To connect to Slave server obtain its location using CgwHelper.GetSlaveServerLocation method, and build location list as an array of one element containing received location.
To connect to Slave server or Network agent lower in server hierarchy, build locations list as an ordered array of slave servers and Network agent.

Example1: if you want to connect to Network agent NA1, which is managed by MasterServer1:

Get NetworkAgent1 location using CgwHelper.GetNagentLocation call to MasterServer1
Build locations list as an array of one element, containing NetworkAgent1 location
Create gateway connection by calling GatewayConnection.PrepareGatewayConnection on MasterServer1 and get authentication key.
Create new session using Session.CreateSession method using KSCGW authentication scheme with provided one-time authentication key.
All calls within created session on any OpenAPI connection to MasterServer1 will be routed to NA1.

After successful authentication this connection may be used to communicate with NetworkAgent1, for example, by calling methods of NagHstCtl, NagRdu, NagGuiCalls, NagRemoteScreen(or NagCgwHelper to recursively create a deeper gateway connection)

Example2: if you want to connect to NetworkAgent2, which is managed by SlaveServer1, and you connected to MasterServer1, where MasterServer1 is a direct master server for SlaveServer1:

Get SlaveServer1 location using CgwHelper.GetSlaveServerLocation call to MasterServer1
Get NetworkAgent2 location using CgwHelper.GetNagentLocation call to SlaveServer1
Build locations list as an array of two elements: first is SlaveServer1 location, second is NetworkAgent2 location.
Create gateway connection by calling GatewayConnection.PrepareGatewayConnection on MasterServer1 and get authentication key.
Create new connection to MasterServer1 using KSCGW authentication scheme with provided one-time authentication key.

After successful authentication this connection may be used to communicate with NetworkAgent2, for example, by calling methods of NagHstCtl, NagRdu, NagGuiCalls, NagRemoteScreen (or NagCgwHelper to recursively create a deeper gateway connection).

With KlAkOAPI Python package slave server can be connected as follows:

        # connect to main server with basic authentication to get gateway token
        server_main = KlAkOAPI.AdmServer.KlAkAdmServer.Create('https://ksc-main.example.com', 'username', 'password', verify = False)        
        # step 1: get slave server location
        cgwHelper = KlAkOAPI.CgwHelper.KlAkCgwHelper(server_main)
        slaveServerLocation = cgwHelper.GetSlaveServerLocation(nChildServerId).RetVal()   
        # step 2: build locations list
        arrLocation = [KlAkOAPI.Params.paramParams(slaveServerLocation)]
        # step 3: prepare gateway connection to main server with locations array built on previous step
        gatewayConnection = KlAkOAPI.GatewayConnection.KlAkGatewayConnection(server_main)
        token_on_slave = gatewayConnection.PrepareGatewayConnection(arrLocation).OutPar('wstrAuthKey')
        server_main.Disconnect()        
        # connect slave server
        server = KlAkOAPI.AdmServer.KlAkAdmServer.CreateGateway('https://ksc-main.example.com', token_on_slave, verify = False)

Nagent can be connected as follows:

        # connect to main server with basic authentication to get gateway token
        server_main = KlAkOAPI.AdmServer.KlAkAdmServer.Create('https://ksc-main.example.com', 'username', 'password', verify = False)        
        # step 1: get nagent location
        cgwHelper = KlAkOAPI.CgwHelper.KlAkCgwHelper(server_main)
        nagentLocation = cgwHelper.GetNagentLocation(wsHostName).RetVal()    
        # step 2: build locations list
        arrLocation = [KlAkOAPI.Params.paramParams(nagentLocation)]
        # step 3: prepare gateway connection to main server with locations array built on previous step
        gatewayConnection = KlAkOAPI.GatewayConnection.KlAkGatewayConnection(server_main)
        token_on_nagent = gatewayConnection.PrepareGatewayConnection(arrLocation).OutPar('wstrAuthKey')
        server_main.Disconnect()      
        # connect nagent        
        server = KlAkOAPI.AdmServer.KlAkAdmServer.CreateGateway('https://ksc-main.example.com', token_on_slave, verify = False)

See also: