diff --git a/cookbooks/base/attributes.rb b/cookbooks/base/attributes.rb
index 18a755b..d50ecfb 100644
--- a/cookbooks/base/attributes.rb
+++ b/cookbooks/base/attributes.rb
@@ -9,7 +9,7 @@ end
 
 node.reverse_merge!({
   'base' => {
-    'LXC' => lxc
+    'lxc' => lxc
   }
 })
 
diff --git a/cookbooks/base/default.rb b/cookbooks/base/default.rb
index f81b098..f6e1980 100644
--- a/cookbooks/base/default.rb
+++ b/cookbooks/base/default.rb
@@ -1,3 +1,5 @@
+include_recipe './attributes.rb'
+
 [
   # only install amd64 package
   # http://d.hatena.ne.jp/ritchey/20121229
@@ -33,6 +35,17 @@ remote_file '/etc/update-motd.d/99-motd-update' do
   mode '755'
 end
 
+# If it is inside an LXC, change the apt repository settings:
+if node['base']['lxc']
+  %w( /etc/apt/sources.list /etc/apt/sources.list.d/ubuntu.sources ).each do |conf|
+    remote_file conf do
+      mode   "0644"
+      owner  "root"
+      group  "root"
+    end
+  end
+end
+
 # Install the necessary packages:
 include_recipe './packages.rb'
 include_recipe './eget.rb'
@@ -49,85 +62,52 @@ include_recipe './ufw.rb'
 # `sshd` configurations:
 include_recipe './ssh.rb'
 
-# `fortune` configurations:
-include_recipe './fortune.rb'
-
 # timezone configurations:
 include_recipe './timezone.rb'
+include_recipe './ntp.rb'
 
-# kernel configurations:
-include_recipe './kernel.rb'
+# If it is a VM, do the followings.
+# If it is inside an LXC container, do NOTHING.
+unless node['base']['lxc']
+  # `fortune` configurations:
+  include_recipe './fortune.rb'
 
-# Install mc command:
-include_recipe './mc.rb'
+  # kernel configurations:
+  include_recipe './kernel.rb'
 
-# Install lsyncd command:
-include_recipe './lsyncd.rb'
+  # Install mc command:
+  include_recipe './mc.rb'
 
-# Install starship command:
-include_recipe './starship.rb'
+  # Install lsyncd command:
+  include_recipe './lsyncd.rb'
 
-# Install cloudflared command:
-include_recipe './cloudflared.rb'
+  # Install starship command:
+  include_recipe './starship.rb'
 
-# Disable Ubuntu Pro
-include_recipe './ubuntupro.rb'
+  # Install cloudflared command:
+  include_recipe './cloudflared.rb'
 
-# recipes for Ubuntu 20.04 and later
-case node['platform_version']
-when "20.04", "22.04", "24.04"
-  remote_file '/etc/multipath.conf' do
-    owner 'root'
-    group 'root'
-    mode  '0644'
-
-    notifies :restart, 'service[multipath-tools]'
-  end
-
-  service 'multipath-tools' do
-    action :nothing
-  end
-
-  package 'systemd-timesyncd'
-
-  service 'systemd-timesyncd' do
-    action :enable
-  end
+  # Disable Ubuntu Pro
+  include_recipe './ubuntupro.rb'
 
+  # recipes for Ubuntu 20.04 and later
   case node['platform_version']
-  when "20.04"
-    remote_file '/etc/systemd/timesyncd.conf' do
+  when "20.04", "22.04", "24.04"
+    remote_file '/etc/multipath.conf' do
       owner 'root'
       group 'root'
-      mode '0644'
+      mode  '0644'
 
-      notifies :restart, 'service[systemd-timesyncd]'
+      notifies :restart, 'service[multipath-tools]'
     end
-  when "22.04"
-    remote_file '/etc/systemd/timesyncd.conf' do
-      owner 'root'
-      group 'root'
-      mode '0644'
 
-      source 'files/etc/systemd/timesyncd.2204.conf'
-
-      notifies :restart, 'service[systemd-timesyncd]'
-    end
-  when "24.04"
-    remote_file '/etc/systemd/timesyncd.conf' do
-      owner 'root'
-      group 'root'
-      mode '0644'
-
-      source 'files/etc/systemd/timesyncd.2404.conf'
-
-      notifies :restart, 'service[systemd-timesyncd]'
+    service 'multipath-tools' do
+      action :nothing
     end
   end
-end
 
-
-# AWS EC2 Swap Setting:
-if node['is_ec2']
-  include_recipe './aws_ec2.rb'
+  # AWS EC2 Swap Setting:
+  if node['is_ec2']
+    include_recipe './aws_ec2.rb'
+  end
 end
diff --git a/cookbooks/base/files/etc/apt/sources.list b/cookbooks/base/files/etc/apt/sources.list
new file mode 100644
index 0000000..a2dee82
--- /dev/null
+++ b/cookbooks/base/files/etc/apt/sources.list
@@ -0,0 +1,6 @@
+# deb http://archive.ubuntu.com/ubuntu noble main restricted universe multiverse
+
+# deb http://archive.ubuntu.com/ubuntu noble-updates main restricted universe multiverse
+
+# deb http://archive.ubuntu.com/ubuntu noble-security main restricted universe multiverse
+
diff --git a/cookbooks/base/files/etc/apt/sources.list.d/ubuntu.sources b/cookbooks/base/files/etc/apt/sources.list.d/ubuntu.sources
new file mode 100644
index 0000000..8757a2f
--- /dev/null
+++ b/cookbooks/base/files/etc/apt/sources.list.d/ubuntu.sources
@@ -0,0 +1,11 @@
+Types: deb
+URIs: http://192.168.10.200:8080/ubuntu/apt-mirror/mirror/jp.archive.ubuntu.com/ubuntu/
+Suites: noble noble-updates noble-backports
+Components: main restricted universe multiverse
+Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
+
+Types: deb
+URIs: http://security.ubuntu.com/ubuntu/
+Suites: noble-security
+Components: main restricted universe multiverse
+Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
diff --git a/cookbooks/base/ntp.rb b/cookbooks/base/ntp.rb
new file mode 100644
index 0000000..eeebd2b
--- /dev/null
+++ b/cookbooks/base/ntp.rb
@@ -0,0 +1,39 @@
+package 'systemd-timesyncd'
+
+service 'systemd-timesyncd' do
+  action :enable
+end
+
+case node['platform_version']
+when "20.04", "22.04", "24.04"
+  case node['platform_version']
+  when "20.04"
+    remote_file '/etc/systemd/timesyncd.conf' do
+      owner 'root'
+      group 'root'
+      mode '0644'
+
+      notifies :restart, 'service[systemd-timesyncd]'
+    end
+  when "22.04"
+    remote_file '/etc/systemd/timesyncd.conf' do
+      owner 'root'
+      group 'root'
+      mode '0644'
+
+      source 'files/etc/systemd/timesyncd.2204.conf'
+
+      notifies :restart, 'service[systemd-timesyncd]'
+    end
+  when "24.04"
+    remote_file '/etc/systemd/timesyncd.conf' do
+      owner 'root'
+      group 'root'
+      mode '0644'
+
+      source 'files/etc/systemd/timesyncd.2404.conf'
+
+      notifies :restart, 'service[systemd-timesyncd]'
+    end
+  end
+end
diff --git a/cookbooks/base/packages.rb b/cookbooks/base/packages.rb
index 11b917e..70979a5 100644
--- a/cookbooks/base/packages.rb
+++ b/cookbooks/base/packages.rb
@@ -2,7 +2,7 @@
 execute 'apt update'
 
 # Install the necessary packages:
-%w[build-essential zsh vim-nox debian-keyring curl direnv jq avahi-daemon wget gpg coreutils].each do |pkg|
+%w[build-essential zsh vim-nox debian-keyring curl direnv jq avahi-daemon wget gpg coreutils software-properties-common].each do |pkg|
   package pkg
 end