Deploy TiDB Offline Using Ansible

This guide describes how to deploy a TiDB cluster offline using Ansible.

Prepare

Before you start, make sure that you have:

A download machine
- The machine must have access to the Internet in order to download TiDB-Ansible, TiDB and related packages.
- For Linux operating system, it is recommended to install CentOS 7.3 or later.
Several target machines and one Control Machine
- For system requirements and configuration, see Prepare the environment.
- It is acceptable without access to the Internet.

Step 1: Install system dependencies on the Control Machine

Take the following steps to install system dependencies on the Control Machine installed with the CentOS 7 system.

Download the pip offline installation package to the Control Machine.
```
# tar -xzvf ansible-system-rpms.el7.tar.gz
# cd ansible-system-rpms.el7
# chmod u+x install_ansible_system_rpms.sh
# ./install_ansible_system_rpms.sh
```
Note: This offline installation package includes pip and sshpass, and only supports the CentOS 7 system.
After the installation is finished, you can use pip -V to check whether it is successfully installed.
```
# pip -V
 pip 8.1.2 from /usr/lib/python2.7/site-packages (python 2.7)
```
Note: If pip is already installed to your system, make sure that the version is 8.1.2 or later. Otherwise, compatibility error occurs when you install Ansible and its dependencies offline.

Step 2: Create the `tidb` user on the Control Machine and generate the SSH key

See Create the tidb user on the Control Machine and generate the SSH key.

Step 3: Install Ansible and its dependencies offline on the Control Machine

Currently, the TiDB 2.0 GA version and the master version are compatible with Ansible 2.5. Ansible and the related dependencies are in the tidb-ansible/requirements.txt file.

Download Ansible 2.5 offline installation package.

Install Ansible and its dependencies offline.

# tar -xzvf ansible-2.5.0-pip.tar.gz
# cd ansible-2.5.0-pip/
# chmod u+x install_ansible.sh
# ./install_ansible.sh

View the version of Ansible.

After Ansible is installed, you can view the version using ansible --version.
```
# ansible --version
 ansible 2.5.0
```

Step 4: Download TiDB-Ansible and TiDB packages on the download machine

Install Ansible on the download machine.

Use the following method to install Ansible online on the download machine installed with the CentOS 7 system. After Ansible is installed, you can view the version using ansible --version.
```
# yum install epel-release
# yum install ansible curl
# ansible --version
  ansible 2.5.0
```
Note: Make sure that the version of Ansible is 2.5, otherwise a compatibility issue occurs.
Download TiDB-Ansible.

Use the following command to download the corresponding version of TiDB-Ansible from the GitHub TiDB-Ansible project. The default folder name is tidb-ansible. The following are examples of downloading various versions, and you can turn to the official team for advice on which version to choose.

Download the 2.0 version:
```
git clone -b release-2.0 https://github.com/pingcap/tidb-ansible.git
```
or

Download the master version:
```
git clone https://github.com/pingcap/tidb-ansible.git
```
Run the local_prepare.yml playbook, and download TiDB binary online to the download machine.
```
cd tidb-ansible
ansible-playbook local_prepare.yml
```
After running the above command, copy the tidb-ansible folder to the /home/tidb directory of the Control Machine. The ownership authority of the file must be the tidb user.

Step 5: Configure the SSH mutual trust and sudo rules on the Control Machine

See Configure the SSH mutual trust and sudo rules on the Control Machine.

Step 6: Install the NTP service on the target machines

See Install the NTP service on the target machines.

Note: If the time and time zone of all your target machines are same, the NTP service is on and is normally synchronizing time, you can ignore this step. See How to check whether the NTP service is normal.

Step 7: Configure the CPUfreq governor mode on the target machine

See Configure the CPUfreq governor mode on the target machine.

Step 8: Mount the data disk ext4 filesystem with options on the target machines

See Mount the data disk ext4 filesystem with options on the target machines.

Step 9: Edit the `inventory.ini` file to orchestrate the TiDB cluster

See Edit the inventory.ini file to orchestrate the TiDB cluster.

Step 10: Deploy the TiDB cluster

You do not need to run the playbook in ansible-playbook local_prepare.yml.
You can use the Report button on the Grafana Dashboard to generate the PDF file. This function depends on the fontconfig package and English fonts. To use this function, download the offline installation package, upload it to the grafana_servers machine, and install it. This package includes fontconfig and open-sans-fonts, and only supports the CentOS 7 system.
```
$ tar -xzvf grafana-font-rpms.el7.tar.gz
$ cd grafana-font-rpms.el7
$ chmod u+x install_grafana_font_rpms.sh
$ ./install_grafana_font_rpms.sh
```
See Deploy the TiDB cluster.

Test the TiDB cluster

See Test the TiDB cluster.