We'd like to encourage developers to use language specific dependency managers (virtualenv, composer, maven, bundler, etc) that allow them to control the versions of libraries they use. However, sometimes some packages *must* be installed in the base container images, and those can be requested by creating sub tasks of this task.
Criteria for inclusion:
1. Must *not* be easily installable via the language appropriate package manager.
2. Must be available in Debian Jessie (or Jessie backports) repository
3. Must have a clear rationale for why this is needed, why alternatives are not appropriate and which tool is planning on using this.
Examples of packages that will have an easy time getting installed: `git`, `libmysqlclient-dev`, openssl, build time dependencies, compilers, etc
Examples of packages that'll have a hard time getting installed: `python-requests`, `python-dateutil`, other pure-python/pure-ruby, etc packages.