Executing the Post-installation Command During Node Creation

Background

When creating a node, use the post-installation commands to install tools or perform security hardening on the node. This section provides guidance for you to correctly use the post-installation scripts.

Precautions

Do not use the post-installation script that takes a long time to execute.
The time limit to create a node in the CCE clusters is 30 minutes. If the node is not available within 30 minutes, it will be reclaimed. Therefore, do not run the post-installation script that takes a long time.
Do not directly use the reboot command in the script.
CCE executes the post-installation commands after installing mandatory components on the node. The node will be available only after the post-installation commands are executed. If you run reboot directly, the node may be restarted before its status is reported. As a result, it cannot reach the running state within 30 minutes, and a rollback due to timeout will be triggered. Therefore, do not run the reboot command.

If you need to restart the node, perform the following operations:
- Run the shutdown -r <time > command in the script to delay the restart. For example, you can run shutdown -r 1 to delay the restart for 1 minute.
- After the node is available, manually restart it.

Procedure

Log in to the CCE console. In the navigation pane, choose Clusters. Click the target cluster name to access the cluster console.
Choose Nodes in the navigation pane, click the Nodes tab, click Create Node in the right corner, and configure the parameters.
In the Advanced Settings area, enter the post-installation command.

For example, you can create iptables rules by running a post-installation command to allow a maximum of 25 TCP data packets to be addressed to port 80 per minute and allow a maximum of 100 data packets to be addressed to the port when the limit is exceeded to prevent DDoS attacks.
```
iptables -A INPUT -p tcp --dport 80 -m limit --limit 25/minute --limit-burst 100 -j ACCEPT
```
The command example here is for reference only.
After the configuration, enter the number of nodes to be created and click Next: Confirm.
Click Submit.