Include additional API REST library

[juansebastiani2cat]

Hello,

I've been struggling with the inclusion of an additional library for handling Get requests from the MEC simulation. I need the MEC orchestrator to communicate with an API RESTful server and so I have found the CPR C++ library to do it in C++. I have successfully included the library into the MecOrchestrator.cc as follows:

#include <cpr/cpr.h>

And the project compiles and runs successfully. However, when I actually include a line using the library,

cpr::Response r = cpr::Get(cpr::Url{"http://www.httpbin.org/get"});

the following error arises:

<!> Error: Cannot load library '../../../../src//libsimu5g.so': ../../../../src//libsimu5g.so: undefined symbol: _ZN3cpr7SessionC1Ev

It seems as if it couldn't find the Simu5G library. I already included the additional library into the Makemake Options in the part of Link (additional libraries to link with -l option)

Could you give me please some insights about how to include additional libraries or how to include an API Rest handler please ? Thanks a lot for your help

[giovanninardini]

Hello,

sorry for the delay.

You need to tell OMNeT where to find both the header and the library files. Try with the following procedure:

1. Open "Project Properties"

• go to "C/C++ General -> Paths and Symbols -> Includes [tab]"
• press add and check "Add to all configurations" and "Add to all languages"
• press file system and add the folder wherein the .h files of the cpr library are

• go to "C/C++ General -> Paths and Symbols -> Library Paths [tab]"
• press add and check "Add to all configurations" and "Add to all languages"
• press file system and add the folder wherein the libcpr files are (e.g., /usr/local/lib)

• go to "OMNeT++ -> Makemake -> Options.. -> Link [tab]"
• press "more"
• press the plus symbol and add "cpr

Then re-build everything and try to re-run your simulation.

Best regards.
Giovanni

[giovanninardini]

Hello,

sorry for the delay.

You need to tell OMNeT where to find both the header and the library files. Try with this procedure:

1. Open "Project" -> "Project Properties"

• go to "C/C++ General -> Paths and Symbols -> Includes [tab]"
• press add and check "Add to all configurations" and "Add to all languages"
• press file system and add the folder wherein the cpr .h files are

• go to "C/C++ General -> Paths and Symbols -> Library Paths [tab]"
• press add and check "Add to all configurations" and "Add to all languages"
• press file system and add the folder wherein the libcpr libraries are

• go to "OMNeT++ -> Makemake -> Options.. -> Link [tab]"
• press "more"
• press the plus symbol and add "cpr"

Then try to re-build everything and run your simulation.

Best regards.
Giovanni

[juansebastiani2cat]

Hello,

Thanks for your answer. But as soon as I modify the options in the "Project Properties ->Makemake" and change it from "Custom Makefile" to Makemake (So I can include the cpr as you suggested) the following error appears:

/Simu5G/Makefile seems to be a hand-written makefile, refusing to overwrite it. Please delete it or move it away.