diff --git a/ch4-role-huynm/inventory/hosts b/ch4-role-huynm/inventory/hosts
new file mode 100644
index 0000000..00c98f1
--- /dev/null
+++ b/ch4-role-huynm/inventory/hosts
@@ -0,0 +1,10 @@
+[centos]
+192.168.139.129
+192.168.139.130
+
+[ubuntu]
+192.168.139.131
+
+[linux:children]
+centos
+ubuntu
diff --git a/ch4-role-huynm/roles/apache2/.travis.yml b/ch4-role-huynm/roles/apache2/.travis.yml
new file mode 100644
index 0000000..36bbf62
--- /dev/null
+++ b/ch4-role-huynm/roles/apache2/.travis.yml
@@ -0,0 +1,29 @@
+---
+language: python
+python: "2.7"
+
+# Use the new container infrastructure
+sudo: false
+
+# Install ansible
+addons:
+  apt:
+    packages:
+    - python-pip
+
+install:
+  # Install ansible
+  - pip install ansible
+
+  # Check ansible version
+  - ansible --version
+
+  # Create ansible.cfg with correct roles_path
+  - printf '[defaults]\nroles_path=../' >ansible.cfg
+
+script:
+  # Basic role syntax check
+  - ansible-playbook tests/test.yml -i tests/inventory --syntax-check
+
+notifications:
+  webhooks: https://galaxy.ansible.com/api/v1/notifications/
\ No newline at end of file
diff --git a/ch4-role-huynm/roles/apache2/README.md b/ch4-role-huynm/roles/apache2/README.md
new file mode 100644
index 0000000..225dd44
--- /dev/null
+++ b/ch4-role-huynm/roles/apache2/README.md
@@ -0,0 +1,38 @@
+Role Name
+=========
+
+A brief description of the role goes here.
+
+Requirements
+------------
+
+Any pre-requisites that may not be covered by Ansible itself or the role should be mentioned here. For instance, if the role uses the EC2 module, it may be a good idea to mention in this section that the boto package is required.
+
+Role Variables
+--------------
+
+A description of the settable variables for this role should go here, including any variables that are in defaults/main.yml, vars/main.yml, and any variables that can/should be set via parameters to the role. Any variables that are read from other roles and/or the global scope (ie. hostvars, group vars, etc.) should be mentioned here as well.
+
+Dependencies
+------------
+
+A list of other roles hosted on Galaxy should go here, plus any details in regards to parameters that may need to be set for other roles, or variables that are used from other roles.
+
+Example Playbook
+----------------
+
+Including an example of how to use your role (for instance, with variables passed in as parameters) is always nice for users too:
+
+    - hosts: servers
+      roles:
+         - { role: username.rolename, x: 42 }
+
+License
+-------
+
+BSD
+
+Author Information
+------------------
+
+An optional section for the role authors to include contact information, or a website (HTML is not allowed).
diff --git a/ch4-role-huynm/roles/apache2/defaults/main.yml b/ch4-role-huynm/roles/apache2/defaults/main.yml
new file mode 100644
index 0000000..a01651e
--- /dev/null
+++ b/ch4-role-huynm/roles/apache2/defaults/main.yml
@@ -0,0 +1,3 @@
+---
+# defaults file for apache2
+student: huynm
diff --git a/ch4-role-huynm/roles/apache2/handlers/main.yml b/ch4-role-huynm/roles/apache2/handlers/main.yml
new file mode 100644
index 0000000..055e94e
--- /dev/null
+++ b/ch4-role-huynm/roles/apache2/handlers/main.yml
@@ -0,0 +1,14 @@
+---
+# handlers file for apache2
+  - name: restart web
+    service:
+      name: httpd
+      state: restarted
+      enabled: yes
+    when: ansible_os_family == 'RedHat'
+  - name: restart web
+    service:
+      name: apache2
+      state: restarted
+      enabled: yes
+    when: ansible_os_family == 'Debian'
diff --git a/ch4-role-huynm/roles/apache2/meta/main.yml b/ch4-role-huynm/roles/apache2/meta/main.yml
new file mode 100644
index 0000000..1dc4e2a
--- /dev/null
+++ b/ch4-role-huynm/roles/apache2/meta/main.yml
@@ -0,0 +1,59 @@
+galaxy_info:
+  author: Huy Nguyen
+  description: Ch4-Role Install Apache2
+  company: your company (optional)
+
+  # If the issue tracker for your role is not on github, uncomment the
+  # next line and provide a value
+  # issue_tracker_url: http://example.com/issue/tracker
+
+  # Choose a valid license ID from https://spdx.org - some suggested licenses:
+  # - BSD-3-Clause (default)
+  # - MIT
+  # - GPL-2.0-or-later
+  # - GPL-3.0-only
+  # - Apache-2.0
+  # - CC-BY-4.0
+  license: license (GPL-2.0-or-later, MIT, etc)
+
+  min_ansible_version: 2.9
+
+  # If this a Container Enabled role, provide the minimum Ansible Container version.
+  # min_ansible_container_version:
+
+  #
+  # Provide a list of supported platforms, and for each platform a list of versions.
+  # If you don't wish to enumerate all versions for a particular platform, use 'all'.
+  # To view available platforms and versions (or releases), visit:
+  # https://galaxy.ansible.com/api/v1/platforms/
+  #
+  # platforms:
+  # - name: Fedora
+  #   versions:
+  #   - all
+  #   - 25
+  # - name: SomePlatform
+  #   versions:
+  #   - all
+  #   - 1.0
+  #   - 7
+  #   - 99.99
+  platforms:
+  - name: "EL"
+    versions:
+    - "7"
+  - name: "Ubuntu"
+    versions:
+    - "bionic"
+
+  galaxy_tags: []
+    # List tags for your role here, one per line. A tag is a keyword that describes
+    # and categorizes the role. Users find roles by searching for tags. Be sure to
+    # remove the '[]' above, if you add tags to this list.
+    #
+    # NOTE: A tag is limited to a single word comprised of alphanumeric characters.
+    #       Maximum 20 tags per role.
+
+dependencies: []
+  # List your role dependencies here, one per line. Be sure to remove the '[]' above,
+  # if you add dependencies to this list.
diff --git a/ch4-role-huynm/roles/apache2/tasks/main.yml b/ch4-role-huynm/roles/apache2/tasks/main.yml
new file mode 100644
index 0000000..c260123
--- /dev/null
+++ b/ch4-role-huynm/roles/apache2/tasks/main.yml
@@ -0,0 +1,38 @@
+---
+# tasks file for apache2
+  - name: Install Apache for CentOS, RedHat, ...
+    yum:
+      name: httpd
+      state: latest
+    when: ansible_os_family == 'RedHat'
+
+  - name: Install Apache for Ubuntu, Debian, ...
+    apt:
+      name: apache2
+      state: latest
+    when: ansible_os_family == 'Debian'
+
+  - name: Start Apacheche for CentOS, RedHat, ...
+    service:
+      name: httpd
+      state: started
+      enabled: yes
+    when: ansible_os_family == 'RedHat'
+
+  - name: Start Apacheche for Ubuntu, Debian, ...
+    service:
+      name: apache2
+      state: started
+      enabled: yes
+    when: ansible_os_family == 'Debian'
+
+  - name: copy config file
+    template:
+      src: templates/index.html.j2
+      dest: /var/www/html/index.html
+      mode: 0755
+      owner: root
+    notify: restart web
+
+  - name: Flush handlers
+    meta: flush_handlers
diff --git a/ch4-role-huynm/roles/apache2/templates/index.html.j2 b/ch4-role-huynm/roles/apache2/templates/index.html.j2
new file mode 100644
index 0000000..18d4407
--- /dev/null
+++ b/ch4-role-huynm/roles/apache2/templates/index.html.j2
@@ -0,0 +1 @@
+Hello {{ student }}
diff --git a/ch4-role-huynm/roles/apache2/tests/inventory b/ch4-role-huynm/roles/apache2/tests/inventory
new file mode 100644
index 0000000..878877b
--- /dev/null
+++ b/ch4-role-huynm/roles/apache2/tests/inventory
@@ -0,0 +1,2 @@
+localhost
+
diff --git a/ch4-role-huynm/roles/apache2/tests/test.yml b/ch4-role-huynm/roles/apache2/tests/test.yml
new file mode 100644
index 0000000..7d2d6da
--- /dev/null
+++ b/ch4-role-huynm/roles/apache2/tests/test.yml
@@ -0,0 +1,5 @@
+---
+- hosts: localhost
+  remote_user: root
+  roles:
+    - apache2
diff --git a/ch4-role-huynm/roles/apache2/vars/main.yml b/ch4-role-huynm/roles/apache2/vars/main.yml
new file mode 100644
index 0000000..5d23ceb
--- /dev/null
+++ b/ch4-role-huynm/roles/apache2/vars/main.yml
@@ -0,0 +1,2 @@
+---
+# vars file for apache2
diff --git a/ch4-role-huynm/site.yaml b/ch4-role-huynm/site.yaml
new file mode 100644
index 0000000..fcec9df
--- /dev/null
+++ b/ch4-role-huynm/site.yaml
@@ -0,0 +1,27 @@
+- name: Apache web server Roles
+  hosts: all
+  gather_facts: yes
+  become: yes
+
+  tasks:
+    - name: Apache role
+      import_role:
+        name: apache2
+
+#  - name: test
+#      local_action: shell ip a
+#      register: ps
+#  - debug: var=ps.stdout_lines
+#
+
+#    - name: Check Web page
+#      local_action: shell curl http://{{ inventory_hostname }}
+#      register: ps
+#    - debug: var=ps.stdout_lines
+
+    - name: Check Web page
+      local_action:
+        module: shell
+        args: curl http://{{ inventory_hostname }}
+      register: ps
+    - debug: var=ps.stdout_lines
diff --git a/ch4-role/ansible.cfg b/ch4-role/ansible.cfg
new file mode 100644
index 0000000..7446a5e
--- /dev/null
+++ b/ch4-role/ansible.cfg
@@ -0,0 +1,4 @@
+[defaults]
+host_key_checking = False
+inventory = inventory
+command_warnings=False
\ No newline at end of file
diff --git a/ch4-role/instruction.md b/ch4-role/instruction.md
new file mode 100644
index 0000000..ccd1bcd
--- /dev/null
+++ b/ch4-role/instruction.md
@@ -0,0 +1,58 @@
+# Develop your own role
+
+## Create new empty role
+
+- Create a role called `apache2`
+
+```bash
+ansible-galaxy init apache2
+- Role apache2 was created successfully
+```
+
+- Quick glance at newly created role
+
+```bash
+tree apache2
+apache2
+├── README.md
+├── defaults
+│   └── main.yml
+├── files
+├── handlers
+│   └── main.yml
+├── meta
+│   └── main.yml
+├── tasks
+│   └── main.yml
+├── templates
+├── tests
+│   ├── inventory
+│   └── test.yml
+└── vars
+    └── main.yml
+```
+
+- Role metadata + README.md (sample)
+
+```yaml
+# meta/main.yml
+galaxy_info:
+  author: Hung Tran
+  description: install and configure apache server on Linux
+  company: Axon
+  license: license (GPL-2.0-or-later, MIT, etc)
+  min_ansible_version: "2.9"
+
+  platforms:
+  - name: EL
+    versions:
+    - "7"
+  - name: Ubuntu
+    versions:
+    - "bionic"  
+
+  galaxy_tags: []
+dependencies: []
+```
+
+- 
diff --git a/ch4-role/inventory/group_vars/centos.yaml b/ch4-role/inventory/group_vars/centos.yaml
new file mode 100644
index 0000000..d03d0e8
--- /dev/null
+++ b/ch4-role/inventory/group_vars/centos.yaml
@@ -0,0 +1,2 @@
+apache_service: httpd
+apache_default_site: /usr/share/httpd/noindex
\ No newline at end of file
diff --git a/ch4-role/inventory/group_vars/ubuntu.yaml b/ch4-role/inventory/group_vars/ubuntu.yaml
new file mode 100644
index 0000000..4f23fef
--- /dev/null
+++ b/ch4-role/inventory/group_vars/ubuntu.yaml
@@ -0,0 +1,2 @@
+ansible_python_interpreter: /usr/bin/python3
+apache_default_site: /var/www/html
\ No newline at end of file
diff --git a/ch4-role/inventory/hosts b/ch4-role/inventory/hosts
new file mode 100644
index 0000000..e02db0e
--- /dev/null
+++ b/ch4-role/inventory/hosts
@@ -0,0 +1,13 @@
+[ubuntu]
+ubuntu11 ansible_host=192.168.100.11
+ubuntu12 ansible_host=192.168.100.12
+
+[centos]
+centos21 ansible_host=192.168.100.21
+centos22 ansible_host=192.168.100.22
+
+
+[linux:children]
+ubuntu
+centos
+
diff --git a/ch4-role/roles/apache2/.travis.yml b/ch4-role/roles/apache2/.travis.yml
new file mode 100644
index 0000000..36bbf62
--- /dev/null
+++ b/ch4-role/roles/apache2/.travis.yml
@@ -0,0 +1,29 @@
+---
+language: python
+python: "2.7"
+
+# Use the new container infrastructure
+sudo: false
+
+# Install ansible
+addons:
+  apt:
+    packages:
+    - python-pip
+
+install:
+  # Install ansible
+  - pip install ansible
+
+  # Check ansible version
+  - ansible --version
+
+  # Create ansible.cfg with correct roles_path
+  - printf '[defaults]\nroles_path=../' >ansible.cfg
+
+script:
+  # Basic role syntax check
+  - ansible-playbook tests/test.yml -i tests/inventory --syntax-check
+
+notifications:
+  webhooks: https://galaxy.ansible.com/api/v1/notifications/
\ No newline at end of file
diff --git a/ch4-role/roles/apache2/README.md b/ch4-role/roles/apache2/README.md
new file mode 100644
index 0000000..8c2d4d1
--- /dev/null
+++ b/ch4-role/roles/apache2/README.md
@@ -0,0 +1,36 @@
+Role Name
+=========
+
+This role is designed to install and configure apache2 web server on Linux
+
+Requirements
+------------
+
+No dependancy required
+
+Role Variables
+--------------
+
+A description of the settable variables for this role should go here, including any variables that are in defaults/main.yml, vars/main.yml, and any variables that can/should be set via parameters to the role. Any variables that are read from other roles and/or the global scope (ie. hostvars, group vars, etc.) should be mentioned here as well.
+
+Dependencies
+------------
+
+n/a
+
+Example Playbook
+----------------
+
+- hosts: servers
+  roles:
+      - apache2
+
+License
+-------
+
+BSD
+
+Author Information
+------------------
+
+hungtran177@gmail.com
diff --git a/ch4-role/roles/apache2/defaults/main.yml b/ch4-role/roles/apache2/defaults/main.yml
new file mode 100644
index 0000000..7e67d1c
--- /dev/null
+++ b/ch4-role/roles/apache2/defaults/main.yml
@@ -0,0 +1,4 @@
+---
+# defaults file for apache2
+app_user: student
+apache_service: apache2 # default platform is Ubuntu/Debian
\ No newline at end of file
diff --git a/ch4-role/roles/apache2/handlers/main.yml b/ch4-role/roles/apache2/handlers/main.yml
new file mode 100644
index 0000000..cb29215
--- /dev/null
+++ b/ch4-role/roles/apache2/handlers/main.yml
@@ -0,0 +1,6 @@
+---
+# handlers file for apache2
+- name: Restart apache2
+  service: 
+    name: "{{ apache_service }}"
+    state: restarted
\ No newline at end of file
diff --git a/ch4-role/roles/apache2/meta/main.yml b/ch4-role/roles/apache2/meta/main.yml
new file mode 100644
index 0000000..b770437
--- /dev/null
+++ b/ch4-role/roles/apache2/meta/main.yml
@@ -0,0 +1,37 @@
+galaxy_info:
+  author: Hung Tran
+  description: install and configure apache server on Linux
+  company: Axon
+
+  license: license (GPL-2.0-or-later, MIT, etc)
+
+  min_ansible_version: "2.9"
+
+  # If this a Container Enabled role, provide the minimum Ansible Container version.
+  # min_ansible_container_version:
+
+  #
+  # Provide a list of supported platforms, and for each platform a list of versions.
+  # If you don't wish to enumerate all versions for a particular platform, use 'all'.
+  # To view available platforms and versions (or releases), visit:
+  # https://galaxy.ansible.com/api/v1/platforms/
+  #
+  platforms:
+  - name: EL
+    versions:
+    - "7"
+  - name: Ubuntu
+    versions:
+    - "bionic"
+
+  galaxy_tags: []
+    # List tags for your role here, one per line. A tag is a keyword that describes
+    # and categorizes the role. Users find roles by searching for tags. Be sure to
+    # remove the '[]' above, if you add tags to this list.
+    #
+    # NOTE: A tag is limited to a single word comprised of alphanumeric characters.
+    #       Maximum 20 tags per role.
+
+dependencies: []
+  # List your role dependencies here, one per line. Be sure to remove the '[]' above,
+  # if you add dependencies to this list.
diff --git a/ch4-role/roles/apache2/tasks/main.yml b/ch4-role/roles/apache2/tasks/main.yml
new file mode 100644
index 0000000..47ba5ac
--- /dev/null
+++ b/ch4-role/roles/apache2/tasks/main.yml
@@ -0,0 +1,18 @@
+---
+# tasks file for apache2
+- name: Install Apache2 on Ubuntu
+  package:
+    name: "{{ apache_service }}" 
+    state: present
+
+- name: Configuring service 
+  service:
+    name: "{{ apache_service }}"
+    state: started
+    enabled: yes
+
+- name: Copy index test page
+  template:
+    src: "templates/index.html.j2"
+    dest: "{{ apache_default_site }}/index.html"
+  notify: Restart apache2
diff --git a/ch4-role/roles/apache2/templates/index.html.j2 b/ch4-role/roles/apache2/templates/index.html.j2
new file mode 100644
index 0000000..48d5458
--- /dev/null
+++ b/ch4-role/roles/apache2/templates/index.html.j2
@@ -0,0 +1 @@
+Hello {{ app_user }}
\ No newline at end of file
diff --git a/ch4-role/roles/apache2/tests/inventory b/ch4-role/roles/apache2/tests/inventory
new file mode 100644
index 0000000..878877b
--- /dev/null
+++ b/ch4-role/roles/apache2/tests/inventory
@@ -0,0 +1,2 @@
+localhost
+
diff --git a/ch4-role/roles/apache2/tests/test.yml b/ch4-role/roles/apache2/tests/test.yml
new file mode 100644
index 0000000..7d2d6da
--- /dev/null
+++ b/ch4-role/roles/apache2/tests/test.yml
@@ -0,0 +1,5 @@
+---
+- hosts: localhost
+  remote_user: root
+  roles:
+    - apache2
diff --git a/ch4-role/site.yml b/ch4-role/site.yml
new file mode 100644
index 0000000..98a7d83
--- /dev/null
+++ b/ch4-role/site.yml
@@ -0,0 +1,16 @@
+- name: Setup Apache web server
+  hosts: all
+  gather_facts: yes
+  become: yes
+  roles: 
+    - apache2
+  tasks:
+    - meta: flush_handlers
+    
+    - name: Check the welcome page
+      shell: curl {{ inventory_hostname }}
+      register: welcome_page
+
+    - name: Display welcome page
+      debug:
+        msg: "{{ welcome_page.stdout }}"
\ No newline at end of file