Problem linking against inet while dockerizing

[phdavis1027]

I am trying to build a Docker image from the tag omnetpp/inet:o6.0-4.4.1. Once I move model into the container, I run the executable generated by opp_makemake's makefile with the flag -l $INET_ROOT/src/INET, but I get an error message saying that no libINET.so can be found. Any insight would be appreciated, I'm still very confused by the omnetpp CLI.

Best,
Phillip

[rhornig]

If you have an executable that uses the libINET.so as a shared library you must either:

• Add the <inet_root>/src directory to the LD_LIBRARY_PATH environment variable (i.e. the location of the library).
• Or during the linking phase of your executable, you must provide a -Wl,-rpath,<omnetpp_root>/src option to add the location of the lib to the runtime path.

[phdavis1027]

Even when I build in the container I get an error saying that it can't resolve a particular kind of link extended from Etherlink. It's successfully loading NEDs from $INET_ROOT/src/inet and I'm running ./models -l $INET_ROOT/src/INET, so it should be linking properly.

EDIT: I found the source of the issue. Now I'm fairly sure I'm just trying to port the code to the newer version of Omnet/Inet that ships with the container image.

[phdavis1027]

Incidentally, wouldn't it make more sense to install the inet .so in a system directory, or at least in a local directory called lib? I would not normally look for library files in a directory called src

[rhornig]

Yeah, for a normal program, installing it in the system lib folder would be the right choice but OMNeT++ and INET is not a fixed tool, but something the end user constantly tweak, recompile modify (at least in most cases) so we keep everything in the source tree and avoid system wide changes (installing into lib). Because of this we have to manually fiddle with the library path (both link and runtime). This is bad, but we are mostly hiding it from the user and much better than requiring the user to do sudo make install on each model change.

I have to admit the location of src for the final executable is ugly but it has some historical reasons (in INET). Someday we might change that.

[rhornig]

Oh, one shortcut to get it working: have you tried using opp_env? That tool allows you to setup any working combination of omnet/inet. There is also a docker image that contains a pre-installed opp_env tool so you can build on top of that to create your own

[phdavis1027]

Thanks for the suggestion, we might look into that for future use (for example if our project lives long enough that we wind up having to support multiple versions) but I wound up just reading through the code and giving specific indices into the gate arrays.