Running PDFtk on Amazon Linux is possible. I wrote a blog post about running PDFtk on AWS Lambda, which runs on Amazon Linux: https://lob.com/blog/aws-lambda-pdftk/.
It should be entirely possible to use the binary I compiled, along with libgcj.so to run PDFtk on an Amazon Linux EC2. The binary and shared library in this repository should work for you: https://github.com/lob/lambda-pdftk-example
The basics steps to get PDFtk running on Amazon Linux are to compile it from source on CentOS 6, then copy the
pdftk binary and
libgcj.so.10 (usually located in
/usr/lib64/ to your Amazon Linux machine.
Place the binary in a directory in your
libgcj.so.10 in a directory in your
LD_LIBRARY_PATH so the system knows where to find them.
Alternatively you can run the binary directly:
LD_LIBRARY_PATH=/path/to/libgcj.so.10 /path/to/pdftk --version
You can skip the compile step by using the binary and shared library in the
bin/ directory of the Github project I linked to above.