diff --git a/Gemfile b/Gemfile
index f4760c3..8b3af2e 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,7 +4,8 @@ source 'https://rubygems.org'
 gemspec
 
 group :development do
+  gem 'rake'
+  gem 'rspec', '~> 2.11'
   gem 'vagrant',     github: 'mitchellh/vagrant'
   gem 'vagrant-lxc', github: 'fgrehm/vagrant-lxc'
-  gem 'rake'
 end
diff --git a/Gemfile.lock b/Gemfile.lock
index 630680f..789071d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -27,6 +27,7 @@ GEM
   specs:
     childprocess (0.3.9)
       ffi (~> 1.0, >= 1.0.11)
+    diff-lcs (1.2.4)
     erubis (2.7.0)
     ffi (1.8.1)
     i18n (0.6.4)
@@ -36,12 +37,21 @@ GEM
       net-ssh (>= 2.6.5)
     net-ssh (2.6.7)
     rake (10.0.4)
+    rspec (2.13.0)
+      rspec-core (~> 2.13.0)
+      rspec-expectations (~> 2.13.0)
+      rspec-mocks (~> 2.13.0)
+    rspec-core (2.13.1)
+    rspec-expectations (2.13.0)
+      diff-lcs (>= 1.1.3, < 2.0)
+    rspec-mocks (2.13.1)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
   rake
+  rspec (~> 2.11)
   vagrant!
   vagrant-cachier!
   vagrant-lxc!
diff --git a/Rakefile b/Rakefile
index 09df0ec..3004b1d 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,5 +1,11 @@
-Dir['./tasks/**/*.rake'].each { |f| load f }
-
 require 'bundler/gem_tasks'
+require 'rspec/core/rake_task'
 
-task :ci => ['spec:unit']
+task :default => [:spec]
+
+namespace :spec do
+  RSpec::Core::RakeTask.new('unit') do |t|
+    t.pattern = 'spec/unit/**/*_spec.rb'
+  end
+end
+task :spec => ['spec:unit']
diff --git a/lib/vagrant-cachier/action/configure_apt_proxy.rb b/lib/vagrant-cachier/action/configure_apt_proxy.rb
new file mode 100644
index 0000000..4461566
--- /dev/null
+++ b/lib/vagrant-cachier/action/configure_apt_proxy.rb
@@ -0,0 +1,53 @@
+require 'tempfile'
+
+module VagrantPlugins
+  module Cachier
+    class Action
+      class ConfigureAptProxy
+        attr_reader :logger
+
+        def initialize(app, env)
+          @app    = app
+          @logger = Log4r::Logger.new("vagrant::cachier::action::configure_apt_proxy")
+        end
+
+        def call(env)
+          @app.call env
+
+          proxy_config = env[:machine].config.apt_proxy
+          if !proxy_config.enabled?
+            logger.debug "apt_proxy not enabled or configured"
+          elsif !proxy_conf_capability?(env[:machine])
+            env[:ui].info "Skipping Apt proxy config as the machine does not support it"
+          else
+            env[:ui].info "Configuring proxy for Apt..."
+            write_apt_proxy_conf(env[:machine], proxy_config)
+          end
+        end
+
+        def write_apt_proxy_conf(machine, config)
+          logger.debug "Configuration:\n#{config}"
+
+          temp = Tempfile.new("vagrant")
+          temp.binmode
+          temp.write(config)
+          temp.close
+
+          machine.communicate.tap do |comm|
+            comm.upload(temp.path, "/tmp/vagrant-apt-proxy-conf")
+            comm.sudo("cat /tmp/vagrant-apt-proxy-conf > #{proxy_conf_path(machine)}")
+            comm.sudo("rm /tmp/vagrant-apt-proxy-conf")
+          end
+        end
+
+        def proxy_conf_capability?(machine)
+          machine.guest.capability?(:apt_proxy_conf)
+        end
+
+        def proxy_conf_path(machine)
+          machine.guest.capability(:apt_proxy_conf)
+        end
+      end
+    end
+  end
+end
diff --git a/lib/vagrant-cachier/apt_proxy_config.rb b/lib/vagrant-cachier/apt_proxy_config.rb
new file mode 100644
index 0000000..bdb77a0
--- /dev/null
+++ b/lib/vagrant-cachier/apt_proxy_config.rb
@@ -0,0 +1,88 @@
+require 'vagrant'
+
+module VagrantPlugins
+  module Cachier
+    class AptProxyConfig < Vagrant.plugin("2", :config)
+      # HTTP proxy for Apt
+      attr_accessor :http
+
+      # HTTPS proxy for Apt
+      attr_accessor :https
+
+      def initialize
+        @http  = UNSET_VALUE
+        @https = UNSET_VALUE
+      end
+
+      def finalize!
+        @http = override_from_env_var('http', @http)
+        @http = nil if @http == UNSET_VALUE
+
+        @https = override_from_env_var('https', @https)
+        @https = nil if @https == UNSET_VALUE
+      end
+
+      def enabled?
+        !http.nil? || !https.nil?
+      end
+
+      # @return [String] the full configuration stanza
+      def to_s
+        "#{config_for('http')}#{config_for('https')}"
+      end
+
+      private
+
+      def override_from_env_var(proto, default)
+        ENV.fetch("APT_PROXY_#{proto.upcase}", default)
+      end
+
+      def config_for(proto)
+        ConfigValue.new(proto, send(proto.to_sym))
+      end
+
+      class ConfigValue
+
+        attr_reader :proto, :value
+
+        # @param proto [String] the protocol ("http", "https")
+        # @param value [Object] the configuration value
+        def initialize(proto, value)
+          @proto = proto
+          @value = value
+        end
+
+        # @return [String] the full Apt configuration line
+        def to_s
+          set? ? %Q{Acquire::#{proto}::Proxy "#{proxy_uri}";\n} : ""
+        end
+
+        private
+
+        def set?
+          value && !value.empty?
+        end
+
+        def direct?
+          value.upcase == "DIRECT"
+        end
+
+        def proxy_uri
+          direct? ? "DIRECT" : "#{prefix}#{value}#{suffix}"
+        end
+
+        def prefix
+          "#{proto}://" if value !~ %r{^.*://}
+        end
+
+        def suffix
+          ":#{default_port}" if value !~ %r{:\d+$}
+        end
+
+        def default_port
+          3142
+        end
+      end
+    end
+  end
+end
diff --git a/lib/vagrant-cachier/cap/debian/apt_proxy_conf.rb b/lib/vagrant-cachier/cap/debian/apt_proxy_conf.rb
new file mode 100644
index 0000000..0329a59
--- /dev/null
+++ b/lib/vagrant-cachier/cap/debian/apt_proxy_conf.rb
@@ -0,0 +1,13 @@
+module VagrantPlugins
+  module Cachier
+    module Cap
+      module Debian
+        module AptProxyConf
+          def self.apt_proxy_conf(machine)
+            '/etc/apt/apt.conf.d/01proxy'
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/vagrant-cachier/plugin.rb b/lib/vagrant-cachier/plugin.rb
index 31a2870..e5d94c4 100644
--- a/lib/vagrant-cachier/plugin.rb
+++ b/lib/vagrant-cachier/plugin.rb
@@ -8,6 +8,11 @@ module VagrantPlugins
         Config
       end
 
+      config 'apt_proxy' do
+        require_relative 'apt_proxy_config'
+        AptProxyConfig
+      end
+
       guest_capability 'linux', 'gemdir' do
         require_relative 'cap/linux/gemdir'
         Cap::Linux::Gemdir
@@ -18,6 +23,11 @@ module VagrantPlugins
         Cap::Debian::AptCacheDir
       end
 
+      guest_capability 'debian', 'apt_proxy_conf' do
+        require_relative 'cap/debian/apt_proxy_conf'
+        Cap::Debian::AptProxyConf
+      end
+
       guest_capability 'redhat', 'yum_cache_dir' do
         require_relative 'cap/redhat/yum_cache_dir'
         Cap::RedHat::YumCacheDir
@@ -30,7 +40,9 @@ module VagrantPlugins
 
       install_action_hook = lambda do |hook|
         require_relative 'action'
+        require_relative 'action/configure_apt_proxy'
         hook.after Vagrant::Action::Builtin::Provision, VagrantPlugins::Cachier::Action::Install
+        hook.after Vagrant::Action::Builtin::Provision, VagrantPlugins::Cachier::Action::ConfigureAptProxy
       end
       action_hook 'set-shared-cache-on-machine-up',     :machine_action_up, &install_action_hook
       action_hook 'set-shared-cache-on-machine-reload', :machine_action_reload, &install_action_hook
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
new file mode 100644
index 0000000..9a15a42
--- /dev/null
+++ b/spec/spec_helper.rb
@@ -0,0 +1,10 @@
+RSpec.configure do |config|
+  config.expect_with :rspec do |c|
+    c.syntax = :expect
+  end
+  config.color = true
+  config.tty = true
+end
+
+require 'tempfile'
+require 'vagrant-cachier'
diff --git a/spec/unit/support/shared/apt_proxy_config.rb b/spec/unit/support/shared/apt_proxy_config.rb
new file mode 100644
index 0000000..b5958a6
--- /dev/null
+++ b/spec/unit/support/shared/apt_proxy_config.rb
@@ -0,0 +1,103 @@
+def config_with(options)
+  instance.tap do |c|
+    options.each_pair { |k, v| c.send("#{k}=".to_sym, v) }
+    c.finalize!
+  end
+end
+
+def conf_line(proto, name, port = 3142)
+  if name == :direct
+    %Q{Acquire::#{proto}::Proxy "DIRECT";\n}
+  else
+    %Q{Acquire::#{proto}::Proxy "#{proto}://#{name}:#{port}";\n}
+  end
+end
+
+def conf_line_pattern(proto, name, port = 3142)
+  "^#{Regexp.escape(conf_line(proto, name, port))}"
+end
+
+shared_examples "apt proxy config" do |proto|
+  context "#{proto} proxy" do
+
+    context "with ip" do
+      subject        { config_with(proto => "10.1.2.3") }
+      its(:enabled?) { should be_true }
+      its(:to_s)     { should eq conf_line(proto, "10.1.2.3") }
+    end
+
+    context "with name" do
+      subject        { config_with(proto => "proxy.example.com") }
+      its(:enabled?) { should be_true }
+      its(:to_s)     { should eq conf_line(proto, "proxy.example.com") }
+    end
+
+    context "with name and port" do
+      subject        { config_with(proto => "acng:8080") }
+      its(:enabled?) { should be_true }
+      its(:to_s)     { should eq conf_line(proto, "acng", 8080) }
+    end
+
+    context "with protocol and name" do
+      subject        { config_with(proto => "#{proto}://proxy.foo.tld") }
+      its(:enabled?) { should be_true }
+      its(:to_s)     { should eq conf_line(proto, "proxy.foo.tld") }
+    end
+
+    context "with protocol and name and port" do
+      subject        { config_with(proto => "#{proto}://prism.nsa.gov:666") }
+      its(:enabled?) { should be_true }
+      its(:to_s)     { should eq conf_line(proto, "prism.nsa.gov", 666) }
+    end
+
+    ["DIRECT", "direct"].each do |direct|
+      context "with #{direct.inspect}" do
+        subject        { config_with(proto => direct) }
+        its(:enabled?) { should be_true }
+        its(:to_s)     { should eq conf_line(proto, :direct) }
+      end
+    end
+
+    [false, ""].each do |unset|
+      context "with #{unset.inspect}" do
+        subject        { config_with(proto => unset) }
+        its(:enabled?) { should be_true }
+        its(:to_s)     { should eq "" }
+      end
+    end
+
+    context "with nil" do
+      subject        { config_with(proto => nil) }
+      its(:enabled?) { should be_false }
+      its(:to_s)     { should eq "" }
+    end
+
+  end
+end
+
+shared_examples "apt proxy env var" do |var, proto|
+  context var do
+    let(:conf) { config_with(http: "acng:8080", https: "ssl-proxy:8443") }
+
+    it "sets #{proto} proxy" do
+      ENV[var] = "myproxy"
+      expect(conf.to_s).to match conf_line_pattern(proto, "myproxy")
+    end
+
+    it "does not set other proxies" do
+      ENV[var] = "myproxy:2345"
+      conf = config_with({})
+      expect(conf.to_s).to eq conf_line(proto, "myproxy", 2345)
+    end
+
+    it "sets empty configuration" do
+      ENV[var] = ""
+      expect(conf.to_s).to_not match %r{#{proto}://}
+    end
+
+    it "sets direct configuration" do
+      ENV[var] = "direct"
+      expect(conf.to_s).to match conf_line_pattern(proto, :direct)
+    end
+  end
+end
diff --git a/spec/unit/vagrant-cachier/apt_proxy_config_spec.rb b/spec/unit/vagrant-cachier/apt_proxy_config_spec.rb
new file mode 100644
index 0000000..e740f17
--- /dev/null
+++ b/spec/unit/vagrant-cachier/apt_proxy_config_spec.rb
@@ -0,0 +1,34 @@
+require 'spec_helper'
+require 'unit/support/shared/apt_proxy_config'
+require 'vagrant-cachier/apt_proxy_config'
+
+describe VagrantPlugins::Cachier::AptProxyConfig do
+  let(:instance) { described_class.new }
+
+  before :each do
+    # Ensure tests are not affected by environment variables
+    %w[APT_PROXY_HTTP APT_PROXY_HTTPS].each { |k| ENV.delete(k) }
+  end
+
+  context "defaults" do
+    subject        { config_with({}) }
+    its(:enabled?) { should be_false }
+    its(:to_s)     { should eq "" }
+  end
+
+  include_examples "apt proxy config", "http"
+  include_examples "apt proxy config", "https"
+
+  context "with both http and https proxies" do
+    subject        { config_with(http: "10.2.3.4", https: "ssl-proxy:8443") }
+    its(:enabled?) { should be_true }
+    its(:to_s)     { should match conf_line_pattern("http", "10.2.3.4") }
+    its(:to_s)     { should match conf_line_pattern("https", "ssl-proxy", 8443) }
+  end
+
+  context "with env var" do
+    include_examples "apt proxy env var", "APT_PROXY_HTTP", "http"
+    include_examples "apt proxy env var", "APT_PROXY_HTTPS", "https"
+  end
+
+end