Remote API call config

I2Rest Server can perform call to a program located on another IBM i server (for shortness and clarity hereinafter in this page IBM i with i2Rest Server started on it will be referred as i2Rest Server IBM i, IBM i with a located on it program to be called remotly will be referred as target IBM i).

Step 1

Install i2Rest on the target IBM i.

Step 2

Create DDM file on i2Rest Server IBM i using CRTDDMF command.

CRTDDMF FILE(QGPL/RMTSYS) RMTFILE(QGPL/RMTSYS) RMTLOCNAME(<target IBM i IP> *IP)                     

Step 3

Create text file named I2RESTECHO.PCML anywhere on target IBM i IFS, for example "/tmp/PCML/i2restecho.pcml". Copy and paste following code. It represents a description for the sample program I2RESTECHO, that is included into i2Rest Server installation for demonstration purposes:

<pcml version="1.0">

   <program name="echo" path="/QSYS.LIB/%LIBL%.LIB/I2RESTECHO.PGM">
      <data name="echo" usage="inputoutput" type="char" length="10" trim="both"/>
   </program>

</pcml>

Step 4

Register two users on IBM i. The first will be used as a demonstrative OAuth2 resource owner, and the second one as an OAuth2 client.

Step 5

Contact your system administrator for your i2Rest Server IBM i server host name (or IP) and two available ports for "main" and "management" gates of your first i2Rest Server instance. Create file config.json (you can name it with any name and put it into any available IFS folder). Сopy and paste the snippet bellow. Replace with appropriate values highlighted with bold parts: host_name, ports, pcml_file, system name, user (resource owner) and client.

Basic configuration remote API call variant (differences are highlighted in gray):

{
   "gates":
   {
      "main"       : {"url":"http://<host_name>[:port] (for example api.i2rest.com:1234)"},
      "management" : {"url":"http://<host_name>[:port] (for example api.i2rest.com:4321)"},
      "system"     : {"url":"http://<host_name>[:port] (for example api.i2rest.com:4567)"}
   },
   "session_systems":
   [
      {  "name"   : "*ANONYMOUS", 
         "submit" : "SBMRMTCMD DDMFILE(QGPL/RMTSYS)
                              CMD('SBMJOB CMD(CALL I2REST
                                             PARM(''-session''
                                                   ''-url'' ''${surl}''
                                                   ''-uid'' ''${uid}''
                                                   ''-init' ''ADDLIBLE I2REST''))')"
      },
      {  "name"   : <system name> (for example REMOTE)",
         "submit" : "SBMRMTCMD DDMFILE(QGPL/RMTSYS)
                              CMD('SBMJOB CMD(CALL I2REST
                                             PARM(''-session''
                                                   ''-url'' ''${surl}''
                                                   ''-uid'' ''${uid}''
                                                   ''-init' ''ADDLIBLE I2REST''))')"
      }
   ],
   "pcmls":
   [
      {
         "pcml_mount"         : "echo",
         "pcml_file"          : "<complete name of i2restecho.pcml on IFS (for example /tmp/PCML/i2restecho.pcml)>"б
         "valid_in_anonymous" : true
   ],
   "OAuth2":
   {
      "scopes":
      {
         "run_program" : {"description":"Authorized API call"},
         "system_<system_name> (for example REMOTE)" : {"description":"<scope description>"},
      },
      "users":
      {
         "USRX":{"description":"John Johnes,"valid_clients":{"TSTCLNT":{"scopes":["run_program"]}}}
      },
      "clients":
      {
         "TSTCLNT":{"redirect_uri":"<main gate URL>/oauth2/redirect", 
                   "description":"Test client", 
                   "valid_scopes":["run_program"],
                   "valid_grant_types":["authorization_code"]}
      },
      "tokens": {"type":"token"},"codes":{"type":"code"}
   } 
}

Both "run program" and "system_<system_name>" scopes must be specified obtaining OAuth2 token to perform authorized remote API call.
Anonymous remote sessions, that allows API call without OAuth2 token obtained, are also possible. SBMRMTCMD command must be defined under *ANONYMOUS session system to provide this feature (as it shown above).
Now you are ready to start serving remote API call.