How do I bundle a Custom C Shared Library with Java Application in Cloud Foundry?

Question

I have previously been deploying a java application successfully in Cloud Foundry. However, now the developers have added a shared library compiled from C. I have added the .so to the .zip file (I'm using universal packager and deploying to Cloud Foundry by zip file) and ensured the .so is executable. However, when I deploy I get an error:

2016-12-23T14:39:01.013+00:00 [STG/0] [OUT] -----> Java Buildpack Version: eba4df6 | git://github.com/cloudfoundry/java-buildpack.git#eba4df6
2016-12-23T14:39:01.017+00:00 [STG/0] [ERR] [Buildpack] ERROR Compile failed with exception #<RuntimeError: No container can run this application. Please ensure that you’ve pushed a valid JVM artifact or artifacts using the -p command line argument or path manifest entry. Information about valid JVM artifacts can be found at https://github.com/cloudfoundry/java-buildpack#additional-documentation.
2016-12-23T14:39:01.017+00:00 [STG/0] [ERR] No container can run this application. Please ensure that you’ve pushed a valid JVM artifact or artifacts using the -p command line argument or path manifest entry. Information about valid JVM artifacts can be found at https://github.com/cloudfoundry/java-buildpack#additional-documentation.
2016-12-23T14:39:01.022+00:00 [STG/0] [ERR] Failed to compile droplet
2016-12-23T14:39:01.024+00:00 [STG/0] [OUT] Exit status 223

So my understanding is that I need to created a Custom Buildpack from the Java Buildpack. However, I am getting stuck with the code at this point: https://github.com/ONSdigital/java-buildpack/blob/master/bin/compile#L28

# Adding crf tagger library
status "Adding crf tagger support"
cp $bp_dir/parsers/src/main/resources/libbackend.so $build_dir/vendor/

# update the PATH
status "Building runtime environment"
mkdir -p $build_dir/.profile.d
echo "export PATH=\"$HOME/bin:\$HOME/vendor/:\$PATH\";" > $build_dir/.profile.d/crftagger.sh
echo "export LD_LIBRARY_PATH=\"\$HOME/vendor/\";" >> $build_dir/.profile.d/crftagger.sh

From what I can gather I only need to modify the compile stage. What do I need to do to copy over the .so and have the Buildpack run successfully.

Answer 1

Please take a look to this https://docs.cloudfoundry.org/devguide/deploy-apps/deploy-app.html#profile

Pre-Runtime Hooks that's you need. I can't give you more details because you haven't provided enough information (project structure, do you have .profile in you root and etc.).

If you need to add shared libs try to use attr_reader :additional_libraries https://github.com/cloudfoundry/java-buildpack/blob/master/docs/extending-droplet.md