iService

iService is a set of procedures that help you to exchange data in JSON format with IBM i systems.

Introduction

Advantages Over XMLService

• Light-weighted with essential features
• C/C++ implementation against RPG for more modern language developers
• Simplified parameters of XMLService similar interfaces
• API style declarations of data types against RPG style

Best practice

• Use HTTP REST APIs with HTTPS configuration for IBM i HTTP Apache Server to protect your privacy in public network. See more
• Set appropriate authorities to objects built up with default Makefile or customize with your own rules. See more
• IPC mode should be only considered for high-frequency calls if jobs are with time-consuming intialization as IPC startup also takes additional time cost
• Configure user profiles for IPC mode per your own security and audit policies. See more

Support

This project is still under development. Plan your tests well before deploying on productions.

How to Use

DB2 Stored Procedure

Stored Procedures Registered

call iService.iPlug1M(<control>, <input>, <output>)

HTTP Request

http(s)://<hostname>/iservice/httpcgi.pgm?db2=<db_name>&uid=<user>&pwd=<password>&ctl=<control>&in=<input>&out=<max_output_size>

Configure IBM i HTTP(s) server

--------------------------------
/www/apachedft/conf/httpd.conf:
--------------------------------
 ScriptAlias /iservice/ /QSYS.LIB/ISERVICE.LIB/
 <Directory /QSYS.LIB/ISERVICE.LIB/>
   AllowOverride None
   order allow,deny
   allow from all
   SetHandler cgi-script
   Options +ExecCGI
 </Directory>

ILE External Interfaces

Interface Description

extern "C"  int runService(control, in, in_size, out, out_size_p);
extern "C"  int runService2(control, ccsid, in, in_size, out, out_size_p);
extern "C"  int runServer(ipc_key, ccsid);

PASE Executable

Parameter Description

/usr/bin/iService  'control_flags'  'control_ccsid' 'input'  'max_output_size'
-------------------------------------------------
  ctl         - CHAR(*) - Control flags.           
  ctl_ccsid   - CHAR(*) - CCSID of control flags.
  in          - CHAR(*) - Input buffer.                     
  out_size    - CHAR(*) - Size of output buffer.   

ILE Executable

Parameter Description

iService/Main:
-------------------------------------------------
  ctl         - CHAR(*) - Control flags           
  ctl_ccsid   - INT(4)  - CCSID of control flags  
  in          - CHAR(*) - Input buffer            
  in_size     - INT(4)  - Size of input buffer    
  out         - CHAR(*) - Output buffer           
  out_size    - INT(4)  - Size of output buffer   

Parameter Control

Note: Parameter Control ends with null-termitator and contains up to 1024 bytes with ending null-terminator included.

General Control Flags

Control Flag	Description
*java	Start JAVA debug mode with PASE.
*before(ccsid)	CCSID of input data.
*after(ccsid)	CCSID of output data.
*performance	Inject performance data.

IPC Control Flags

Control Flag	Description
*ipc(/ifs_path/key)	Run as IPC client. If IPC server not exist then submit server job. One IPC server job serves multiple client jobs with users in the same group.
*endipc	End IPC server. IPC server only.
*waitserver(seconds)	IPC client waits IPC server to start up. Value must greater than 0. Default is 5 seconds. IPC client only.
*waitclient(seconds)	IPC server timeout value of listening for clients. 0 means forever. Default is 300 seconds. IPC server only.
*waitdata(seconds)	IPC server timeout value of exchanging data with clients. 0 means forever. Default is 5 seconds IPC server only.
*ipclog	IPC server/clients log messages and dump to spooled files.
*sbmjob[(job:jobd:user)]	Describe for IPC server job to submit. *sbmjob(ISERVICE:QSYS/QSRVJOB:*CURRENT) is used as default.
*ipcsvr(lib/pgm)	IPC server startup program.

Note:

• User profiles of IPC client/server jobs should have access pre-configured to the IPC key path. One way is to assign a group profile with accesses to IPC user profiles.
• Parent path of IPC key directory should be existed before launching IPC mode. IPC key directory is automatically created by IPC server job. All accesses are granted to group profile of current user profile running IPC server job if set.
• One IPC server job does the real work with system functions under the user profile running the IPC server job on behalf of multiple IPC client jobs.

Parameter Input

JSON

JOBINFO

---

Attribute	Value	Description
name	string	Job name.
user	string	Job user.
number	string	Job number.

Retrieve information of job that executes request.

• In IPC mode, it is the server job.
• In non-IPC mode, it is the current job.

SHELL/QSHELL Example

CMD

---

Attribute	Value	Description
exec	cmd	CL call. Default.
	system	Called with system().
	rexx	Called with REXX.
value	Command	String.
error	off	Only escape message reported. Default.
	on	Messages during the execution.
	ignore	Escape message is reported but not stop for 'exec' and 'system'.

CMD Example

SHELL/QSHELL

---

Attribute	Value	Description
value	Command	Command string.
error	off	Only escape message reported. Default.
	on	Messages during the execution.

SHELL/QSHELL Example

PGM/SRVPGM

---

Attribute	Value	Description
name	Name	Program or service program.
lib	Library	Library.
func	Exported symbol	Service program only.
error	off	Only escape message reported. Default.
	on	Messages during the execution.
parm	[{P1}...{Pn}]	Array of parameters P1...Pn
return	{R}	Return value
pase	off	Don't call via PASE. Default value. Users don't need specify this and
let iService decide automatically.
	on	Force to call via PASE.

• Pramater Pn

Attribute	Value	Description
io	in	Input type.
	out	Output type.
	both	Input and output type.
hex	on	Input/output for char(n) in hexadecimal format for non-DS types.
	off	Default
by	value	Parameter value is passed by value. Service program only for non-DS types.
	ref	Parameter value is passed by reference/pointer. Service program only. Default.
type	int(n)	n bytes signed integer. n = 2, 4 or 8
	uint(n)	n bytes unsigned integer. n = 2, 4 or 8
	char(n)	n bytes characters
	float(n)	Fractional precision n
	double(n)	Fractional precision n
	packed(n, m)	Digits n and fractional m
	zoned(n, m)	Digits n and fractional m
	ds	Data structure
value	string/number	For not 'ds' type, string or number value
	[{M1}...{Mn}]	For 'ds' type, arrary of data strucure members

• Data Structure Member Mn

Attribute	Value	Description
type	int(n)	n bytes signed integer. n = 2, 4 or 8
	uint(n)	n bytes unsigned integer. n = 2, 4 or 8
	char(n)	n bytes characters
	float(n)	Fractional precision n
	double(n)	Fractional precision n
	packed(n, m)	Digits n and fractional m
	zoned(n, m)	Digits n and fractional m
	ds	Embedded data structure
value	string/number	String or number value
hex	on	Input/output for char(n) in hexadecimal format for non-DS entries.
	off	Default
by	value	Parameter value is passed by value as default.
	ref	Parameter value is passed by reference/pointer. Only for non-DS entries.

Top level 'ds' used as parameters are always passed by reference. Embedded 'ds' and non-DS type entries in parameter are passed by value as default.

• Return Value R

Attribute	Value	Description
type	int(n)	n bytes signed integer. n = 2, 4 or 8
	uint(n)	n bytes unsigned integer. n = 2, 4 or 8
	char(n)	n bytes characters
	float(n)	Fractional precision n
	double(n)	Fractional precision n
	packed(n, m)	Digits n and fractional m
	zoned(n, m)	Digits n and fractional m
value	string/number	Value returned

Executing program via system interfaces of ILE or PASE is determined internally. By default program is run via system interfaces of ILE. If number of program prameters is great than 32, program is run via system interfaces of PASE.

PGM Executed with ILE Example

PGM Executed with PASE Example

Executing service program via system interfaces of ILE or PASE is determined internally. By default service program is run via system interfaces of ILE. Service program is run via system interfaces of PASE if

• all the paramters are passed in by reference
• number of prameters is great than 32
• return value is required

SRVPGM Executed with ILE Example

SRVPGM Executed with PASE Example

SQL

---

Attribute	Value	Description
servermode	on	Turn on server mode for SQL env if allowed. Default.
	off	Turn off server mode for SQL env if allowed.
error	off	Only escape message reported. Default.
	on	Messages during the execution.
connect	[{CONN1}...{CONNn}]	Connection specification.
operation	[{OP1}...{OPn}]	Run SQL statements.
free	"all"	Free all the connections with the SQL env. Default.
	"none"	Keep all open connections.
	["conn_label", ...]	Array of connection lables in string format. This will turn off freeing all connections.

• Connect Value CONNn

Attribute	Value	Description
conn	connection id	String.
db	db name	String.
uid	user id	String. Not used in SQL server mode.
pwd	password	Authentication charaters. Not used in SQL server mode.
autocommit	on	Automatically commit for connection. Default.
	off	No auto-commit.
commit	no_commit	Reference to SQL_TXN_NO_COMMIT.
	read_uncommitted	Reference to SQL_TXN_READ_UNCOMMITTED.
	read_committed	Reference to SQL_TXN_READ_COMMITTED.
	repeatable_read	Reference to SQL_TXN_REPEATABLE_READ.
	serializeble	Reference to SQL_TXN_SERIALIZABLE.

• Operation Value OPn

Attribute	Value	Description
execDirect	{EXD}	Execute a statement.
exec	{EX}	Execute a statement with parameters.
commit	{CMT}	Commit transaction.

• Commit value CMT

Attribute	Value	Description
conn	connection id	Reference to connections defined in 'connect'.
action	commit	Reference to SQL_COMMIT.
	rollback	Reference to SQL_ROLLBACK.
	commit_hold	Referenc to SQL_COMMIT_HOLD.
	rollback_hold	Referenc to SQL_ROLLBACK_HOLD.

• ExecDirect Value EXD

Attribute	Value	Description
conn	connection id	Reference to connections defined in 'connect'. If not specified, database *LOCAL is used with current job user profile.
rowcount	number	Row count affected by the statement.
value	statement	Statement string.
fetch	{F}	Fetch for SELECT statement only.

• Exec Value EX

Attribute	Value	Description
conn	connection id	Reference to connections defined in 'connect'.
rowcount	number	Row count affected by the statement.
value	statement	Statement string.
parm	[{P1}...{Pn}]	Parameters for SQL statement.
fetch	{F}	Fetch for SELECT statement only.

• Fetch Value F

Attribute	Value	Description
block	all	Fetch all the rows.
	number	Fetch a certain number of rows.
rec	number	Starting position(>=1) of rows to fetch.

• Parameter Value Pn

Attribute	Value	Description
io	in	Input type.
	out	Output type.
	both	Input and output type.
value	number	Specify number for type INTEGER, SMALLINT, BIGINT, FLOAT, DECFLOAT, NUMERIC, DECIMAL, REAL, DOUBLE.
	chars	Specify characters for type CHAR, VARCHAR, TIMESTAMP, DATE, TIME.
	hex chars	Specify in hexadecimal format chars for type GRAPHIC, VARGRAPHIC, BIN, VARBINARY.

SQL Example

Parameter Output

JSON

Overall Status

Attribute	Value	Description
STATUS	0	Successful.
	> 0	Failed. See definitions

Individual Status

Attribute	Value	Description
STATUS	{S1, ..., Sn}	Contains STATUS attributes

• STATUS Attribute Sn

Attribute	Value	Description
CODE	0	Successful.
	> 0	Failed. See definitions
MESSAGE	[]	Array of result messages.
DATA	{}, []	Contains result data.

Build

If you do not have IBM i open source package installed,

1. Start SSH server in your IBM i system by 'STRTCPSVR SERVER(*SSHD)'
2. In IBM i Access Client Solutions(ACS). From menu bar, select 'Tools' and then select item 'Open source package managment' to install on your IBM i system.
3. Use your SSH client to connect your IBM i system.
4. Now you are ready to start the build.

Requirements

Building requires GNU make and gcc. These can be installed with yum: yum install make-gnu gcc

Building

PATH=/QOpenSys/pkgs/bin:$PATH

git clone git@github.com:IBM/iService-ibmi.git

cd iService

make

OR

make LIBRARY=yourlib DBGVIEW=*ALL BINDIR=your_ifs_bin_directory

Security Consideration

• The Makefile used to build up project leaves security configurations to the system administrator. Consider granting *USE to designated users/*PUBLIC and assigning the ownership to privileged user profile based on your own security policy.

• For using HTTP (REST) requests to exchange data with system, consider configuring IBM i HTTP server with secured socket layer to protect your sensitive information.

• The control for accessing the IPC server job is controlled by the authorities to the IPC key in IFS. If user profiles or their group profile running the client jobs have the access to the IPC key, then they can interact with the related IPC server job. *sbmjob is used to indicate under which user profile the server job will run when submitting IPC server jobs. Plan proper policy based on your own requirement in security and audit controls:

  • If expecting an IPC server job can only be accessed by a specific user, consider using *sbmjob(job:jobd:THIS_USER) to submit the IPC server job. Then IPC server job will run under THIS_USER and only serve client job requests from THIS_USER. THIS_USER better have no group profile assigned to share access with others.

  • If expecting the client jobs from a group of users to be served by the same IPC server job, consider using *sbmjob(job:jobd:THAT_USER). The group of users should be assigned with the same group profile. THAT_USER could be the group profile or one of the user profiles, under which you expect the submitted IPC server job is running.

Tests

• CL

> CALL ISERVICE/MAINTEST [/path/file.json|/path/*.json] [ctl_flags]

• nodejs

> node ./iService/test/nodejs/XXX.js

• python

> python3 ./test/python/XXX.py

• http requests

 ./iService/test/html/XXX.html

License

lgpl-2.1