On RHEL/CentOS 7, the Environment Modules utility is provided by the environment-modules package. The package also provides 2 useful tools at /usr/share/Modules/bin that facilitate the conversion of an init shell script into a modulefile:

createmodule.sh
createmodule.py

I usually create symbolic links to those tools at /usr/local/bin:

# cd /usr/local/bin
# ln -s /usr/share/Modules/bin/createmodule.sh
# ln -s /usr/share/Modules/bin/createmodule.py

Converting Software Collection scriptlets into Environment Modules

We can use the tools to convert a Software Collection's enable scriptlet into a modulefile. For example, to convert devtoolset-7's enable scriptlet into a modulefile:

$ createmodule.sh /opt/rh/devtoolset-7/enable 
#%Module 1.0
prepend-path	INFOPATH	/opt/rh/devtoolset-7/root/usr/share/info
prepend-path	LD_LIBRARY_PATH	/opt/rh/devtoolset-7/root/usr/lib64:/opt/rh/devtoolset-7/root/usr/lib:/opt/rh/devtoolset-7/root/usr/lib64/dyninst:/opt/rh/devtoolset-7/root/usr/lib/dyninst:/opt/rh/devtoolset-7/root/usr/lib64:/opt/rh/devtoolset-7/root/usr/lib
prepend-path	MANPATH	/opt/rh/devtoolset-7/root/usr/share/man
prepend-path	PATH	/opt/rh/devtoolset-7/root/usr/bin
prepend-path	PERL5LIB	/opt/rh/devtoolset-7/root//usr/lib64/perl5/vendor_perl:/opt/rh/devtoolset-7/root/usr/lib/perl5:/opt/rh/devtoolset-7/root//usr/share/perl5/vendor_perl
prepend-path	PYTHONPATH	/opt/rh/devtoolset-7/root/usr/lib64/python2.7/site-packages:/opt/rh/devtoolset-7/root/usr/lib/python2.7/site-packages
setenv		PCP_DIR	/opt/rh/devtoolset-7/root

I would then further edit the produced modulefile, by adding help and versioning, and turn it into something like gcc/7.3.1.