Dependencies

August 21, 2022 at 1:39 PM

The Tour of Champions application is not a big project but even such a small project has some dependencies to make life as a developer easier.

  • Linked List
  • Message
  • ILEastic
  • noxDB

The Easy Way

The easiest way to install those dependencies is by using a package management system. Windows has Chocolatey, Android has Google Play Store, Linux has even several package management systems like yum, rpm, apt, dpkg, aptitude, zypper to name just a few (where some are more high-level and some more low-level).

So what has IBM i for managing software in the QSYS file system? Nothing?

There are several ways to install software on IBM i but nothing comes close to what you have on other platforms.

The closest thing we currently have is the iPKG project. It provides a save file containing a command and processing program in the download section and the README on the main page covers the installation. The project wiki has some information on how to use this package manager.

iPKG needs to keep track of some things and creates some objects in its library. By default the library is IPKG but we can also use any other library by using the parameter IPKGLIB on the IPKG command.

Next we need to specify where iPKG should get the packages from. We register the repository from rpgnextgen.com and use the CHAMPIONS library as a base library for iPKG, see parameter ipkglib.

ipkg addrepo 'RPGNextGen https://repo.rpgnextgen.com/repository' ipkglib(champions)

Note: We can also download the repository from the website and put it on the IFS if we don’t have access to the internet.

Each repository has some meta information about the packages it contains. Before we can install anything we need to fetch those meta information from the repository. This can be done very easily with the following command:

ipkg update ipkglib(champions)

Then we can install the packages with some simple commands in the same way you would do with any other package manager.

ipkg install linkedlist ipkglib(champions)
ipkg install message ipkglib(champions)
ipkg install noxdb2 ipkglib(champions)
ipkg install ileastic ipkglib(champions)

This has installed all objects in the library CHAMPIONS on which our web service depends on. Now we can use the CHAMPIONS library for the BIND_LIB parameter on the make build command when building out Tour of Champions project. On top of that it also created a binding directory in CHAMPIONS with the name IPKG where it registered all service programs.

We have installed the service programs but the copybooks are still missing. Luckily we can install them in the same way. Packages which are used for developing software end with -devel. The copybooks are packaged as stream files. So we need some place on the IFS where we want to place the copybooks. We will use champions_include as the include folder for dependencies for this project, like /home/mihael/champions_include. We can pass this as the location on the ipkg command.

Note: You will need to create this directory in the IFS yourself (mkdir champions_include).

ipkg install 'linkedlist-devel' ipkglib(champions) loc('/home/mihael/champions_include')
ipkg install 'message-devel' ipkglib(champions) loc('/home/mihael/champions_include')
ipkg install 'noxdb2-devel' ipkglib(champions) loc('/home/mihael/champions_include')
ipkg install 'ileastic-devel' ipkglib(champions) loc('/home/mihael/champions_include')

Note to be able to install/unpack stream files from our iPKG packages the command iPKG needs the unzip command either at /bin/unzip or at /QOpenSys/pkgs/bin/unzip (yum unzip package)!

As /home/mihael/champions_include contains all the 3rd party dependency copybooks we can use that folder as the include folder on the make build command, INCDIR parameter, for our Tour of Champions project.

To check what has already been installed in our library we can execute the following command:

ipkg list installed ipkglib(champions)

So far the make build command looks like this:

make INCDIR=/home/mihael/include BIND_LIB=CHAMPIONS all > /dev/null

Though we can simplify things a little bit because CHAMPIONS is the default value for BIND_LIB. This shortens our command a bit as we can remove that parameter from the command call.

make INCDIR=/home/mihael/include all > /dev/null

The Hard Way

The other way is to get the source for each dependency and compile it yourself. Have some fun ;-) !

Copybooks

Sometimes we need to adjust the CCSID of the copybooks, f. e. when using git because git changes the CCSID of the files to 1208 (UTF-8).

CHGATR OBJ('/home/mihael/champions_include') ATR(*CCSID) VALUE(850) SUBTREE(*ALL)