tarballs or git submodules for: openssl, httpd and apr in mod_proxy_cluster repo

Task at hand

• we are gradually getting rid of the old build system, moving towards CMake
• we don't want any auxiliary "util" or "helper" scripts hanging around, we want a pure CMake driven project
• mod_proxy_cluster depends on:
  • httpd
    • apr
    • apr-util
    • openssl
    • pcre
    • iconv
• we need to build these from sources

Solutions

Parent CMakeLists downloads tarballs

• we keep openssl and httpd CMakeLists files in the directory structure
• parent CMakeLists downlaods tarballs before children resolution

We use git submodules

• we add the dependencies as git submodules
• parent CMakeLists does not downlaod anything, it merely checkouts into the desired versions of our dependencies
• we need to keep our:

  mod_proxy_cluster/openssl/CMakeLists

  ,

  mod_proxy_cluster/openssl/crypto/CMakeLists

  etc. and submodules; perhaps needs something like openssl_build (our CMakeLists files) and openssl (git submodule) directories and mod_proxy_cluster/CMakeLists taking care of copying prior to children resolution

Gonna prototype and see what works the best.