def get_build_template(name=None, manager='apt'):
    '''get a particular build template, by default we return templates
       that are based on package managers.

       Parameters
       ==========
       name: the full path of the template file to use.
       manager: the package manager to use in the template (yum or apt)

    '''
    base = get_installdir()
    if name is None:
        name = "%s/main/templates/build/singularity-builder-%s.sh" %(base,
                                                                     manager)

    if os.path.exists(name):
        bot.debug("Found template %s" %name)
        return ''.join(read_file(name)) 

    bot.warning("Template %s not found." %name)
get a particular build template, by default we return templates
       that are based on package managers.

       Parameters
       ==========
       name: the full path of the template file to use.
       manager: the package manager to use in the template (yum or apt)