How to install ruby gem packages without Internet?

git_stats is a good tool to analyze the statistics of a git repo, there is an issue tomgi/git_stats#45 How to Install Offline in that project, I think this is a good question, sometimes the speed or quality of Internet is not so fast and stable, or we want to install a gem package on a server that can only access internal network only, so I tried to figure it out, that’s the solution:

Milly/gem-fetch-dependencies is a ruby script posted on gist, it can help us fetch gem packages with the dependency, we can’t just fetch the package we want to use via gem fetch , because it doesn’t handle the dependency issue, that’s why we need this script, download the script(raw) first:

https://gist.github.com/Milly/909564/raw/c3c921e78b6736197558ee44efb84a495f4c1505/gem-fetch-dependencies
[ruby]#!/usr/bin/ruby

require ‘rubygems’
require ‘rubygems/commands/fetch_command’

class Gem::Commands::FetchCommand
def add_version_option_with_fetch_depends
add_version_option_without_fetch_depends
add_option(‘-y’, ‘–[no-]dependencies’,
"Fetch dependent gems") do |value, options|
options[:dependencies] = value
end
end

def get_all_gem_names_with_fetch_depends
@dependent_gem_names || get_all_gem_names_without_fetch_depends
end

def execute_with_fetch_depends
execute_without_fetch_depends
if options[:dependencies] then
@dependent_gem_names = get_dependent_gem_names
options[:version] = nil
execute_without_fetch_depends
end
end

[:add_version_option, :get_all_gem_names, :execute].each do |target|
feature = "fetch_depends"
alias_method "#{target}_without_#{feature}", target
alias_method target, "#{target}_with_#{feature}"
end

private
def get_dependent_gem_names
version = options[:version] || Gem::Requirement.default
request_gem_names = get_all_gem_names_without_fetch_depends.uniq
to_do = fetch_specs_by_names_and_version(request_gem_names, version)
seen = {}

until to_do.empty? do
spec = to_do.shift
next if spec.nil? or seen[spec.name]
seen[spec.name] = true
deps = spec.runtime_dependencies
deps.each do |dep|
requirements = dep.requirement.requirements.map { |req,| req }
all = !dep.prerelease? and
(requirements.length > 1 or
(requirements.first != ">=" and requirements.first != ">"))
result = fetch_spec(dep, all)
to_do.push(result)
end
end

gem_names = seen.map { |name,| name }
gem_names.reject { |name| request_gem_names.include? name }
end

def fetch_specs_by_names_and_version(gem_names, version)
all = Gem::Requirement.default != version
specs = gem_names.map do |gem_name|
dep = Gem::Dependency.new(gem_name, version)
dep.prerelease = options[:prerelease]
fetch_spec(dep, all)
end
specs.compact
end

def fetch_spec(dep, all)
specs_and_sources, errors =
Gem::SpecFetcher.fetcher.fetch_with_errors(dep, all, true,
dep.prerelease?)
if platform = Gem.platforms.last then
filtered = specs_and_sources.select { |s,| s.platform == platform }
specs_and_sources = filtered unless filtered.empty?
end
spec, source_uri = specs_and_sources.sort_by { |s,| s.version }.last
spec
end
end

load `which gem`.rstrip
[/ruby]

and we can easily fetch the gem packages with dependencies with this script like this:
$ ruby gem-fetch-dependencies fetch --dependencies

Once we fetched all the packages, you copy them to everywhere you want, and install them locally:
$ gem install -f --local *.gem