Install gem in local folder

You could just use RVM: Ruby Version Manager. It is a complete version manager, along the lines of node version manager (nvm) and others, in that it allows you to have different versions of ruby and different collections of gems for each project. It does the job of keeping gems isolated from each other as well as from the system ruby, but at the expense of learning a complete version manager.

When run without root, it installs locally in ~/.rvm and doesn't affect other users.

Add the --local flag to your install:

gem install --local request-log-analyzer

If that causes any problems, try downloading the gem manually and pointing gem directly to it using:

gem install --local path/to/gem/filename.gem

If you want to install it to your user home, as per rubygems:

When you use the --user-install option, RubyGems will install the gems to a directory inside your home directory, something like ~/.gem/ruby/1.9.1. The commands provided by the gems you installed will end up in ~/.gem/ruby/1.9.1/bin. For the programs installed there to be available for you, you need to add ~/.gem/ruby/1.9.1/bin to your PATH environment variable.

The command for this would just be

gem install --user-install request-log-analyzer

You can try:

gem install --user-install gem_name