Objectives

After completing this section, you should be able to activate the Web Console management interface to remotely manage and monitor the performance of a Red Hat Enterprise Linux server.

Describing the Web Console

Web Console is a web-based management interface for Red Hat Enterprise Linux 8 designed for managing and monitoring your servers. It is based on the open source Cockpit service.

You can use Web Console to monitor system logs and view graphs of system performance. Additionally, you can use your web browser to change settings using graphical tools in the Web Console interface, including a fully-functional interactive terminal session.

Enabling the Web Console

Red Hat Enterprise Linux 8 installs Web Console by default in all installation variants except a minimal installation. Use the following command to install Web Console:

[user@host ~]$ sudo yum install cockpit

Enable and start the cockpit.socket service, which runs a web server. This step is necessary if you need to connect to the system through the web interface.

[user@host ~]$ sudo systemctl enable --now cockpit.socket
Created symlink /etc/systemd/system/sockets.target.wants/cockpit.socket -> /usr/lib/systemd/system/cockpit.socket.

If you are using a custom firewall profile, you need to add the cockpit service to firewalld to open port 9090 in the firewall:

[user@host ~]$ sudo firewall-cmd --add-service=cockpit --permanent
success
[user@host ~]$ sudo firewall-cmd --reload
success

Logging in to the Web Console

Web Console provides its own web server. Launch Firefox to log in to Web Console. You can log in with the user name and password of any local account on the system, including the root user.

Open https://servername:9090 in your web browser, where servername is the host name or IP address of your server. The connection will be protected by a TLS session. The system is installed with a self-signed TLS certificate by default, and when you initially connect your web browser will probably display a security warning. The cockpit-ws(8) man page provides instructions on how to replace the TLS certificate with one that is properly signed.

Enter your user name and password at the login screen.

Figure 16.1: The Web Console login screen

Optionally, click the Reuse my password for privileged tasks option. This permits you to execute commands with sudo privileges, allowing you to perform tasks such as modifying system information or configuring new accounts.

Click Log In.

Web Console displays the user name on the right side of the title bar. If you choose the Reuse my password for privileged tasks option, the Privileged icon displays to the left of the user name.

Figure 16.2: Privileged user's title bar

If you are logged in as a non-privileged user, the Privileged icon is not displayed.

Figure 16.3: Non-privileged user's title bar

Changing Passwords

Privileged and non-privileged users can change their own passwords while logged in to Web Console. Click Accounts on the navigation bar. Click your account label to open the account details page.

Figure 16.4: Displaying user accounts

As a non-privileged user, you are restricted to setting or resetting your password and managing public SSH keys. To set or reset your password, click Set Password.

Figure 16.5: User account details

Enter your information in the Old Password, New Password, and Confirm New Password fields. Click Set to activate the new password.

Figure 16.6: Setting and resetting passwords

Troubleshooting with the Web Console

Web Console is a powerful troubleshooting tool. You can monitor basic system statistics in real time, inspect system logs, and quickly switch to a terminal session within Web Console to gather additional information from the command-line interface.

Monitoring System Statistics in Real Time

Click Overview on the navigation bar to view information about the system, such as its type of hardware, operating system, host name, and more. Notice that if you are logged in as a non-privileged user, you see all the information but you are not permitted to modify values. The following image displays part of the Overview page.

Figure 16.7: Non-privileged user's Overview page

Click View graphs on the Overview page to view graphs of current system performance for CPU activity, memory use, disk I/O, and network utilization.

Figure 16.8: Non-privileged user's system performance metrics

Inspecting and Filtering Syslog Events

Logs in the navigation bar provides access to analysis tools for the system logs. You can use the menus on the page to filter log messages based on a logging date range, severity level, or both. Web Console uses the current date as the default, but you can click the date menu and specify any range of dates. Similarly, the Severity menu provides options ranging from Everything to more specific severity conditions such as Alert and above, Debug and above, and so on.

Figure 16.9: Log severity selections

Click a row to view details of the log report. In the example below, note the first row that reports on a sudo log message.

Figure 16.10: Log entry selection

The example below shows the details displayed when you click the sudo row. Details of the report include the selected log entry (sudo), the date, time, priority, and syslog facility of the log entry, the host name of the system that reported the log message, and more.

Figure 16.11: Log entry details

Running Commands from a Terminal Session

Terminal in the navigation bar provides access to a fully-functional terminal session within the Web Console interface. This allows you to run arbitrary commands to manage and work with the system and to perform tasks not supported by the other tools provided by Web Console.

The following image displays examples of common commands used to gather additional information. Listing the contents of the /var/log directory provides reminders of log files that may have valuable information. The id command provides quick information such as group membership that may help troubleshoot file access restrictions. The ps au command provides a quick view of processes running in the terminal and the user associated with the process.

Figure 16.12: Non-privileged terminal session troubleshooting

Creating Diagnostic Reports

A diagnostic report is a collection of configuration details, system information, and diagnostic information from a Red Hat Enterprise Linux system. Data collected in the completed report includes system logs and debug information that can be used to troubleshoot issues.

Log in to Web Console as a privileged user. Click Diagnostic Reports on the navigation bar to open the page that creates these reports. Click Create Report to generate a new diagnostic report.

Figure 16.13: Creating a diagnostic report

The interface displays Done! when the report is complete. Click Download report to save the report.

Figure 16.14: Downloading a completed report

Click Save File to save the file and complete the process.

Figure 16.15: Saving a diagnostic report

The completed report is saved to the Downloads directory on the system hosting the web browser used to access Web Console. In this example, the host is workstation.

Figure 16.16: Accessing a completed report

Managing System Services with the Web Console

As a privileged user in Web Console, you can stop, start, enable, and restart system services. Additionally, you can configure network interfaces, configure firewall services, administer user accounts, and more. The following images display common examples for using the Web Console's management tools.

System Power Options

Web Console allows you to restart or shut down the system. Log in to Web Console as a privileged user. Click Overview on the navigation bar to access system power options.

Select the desired option from the menu on the upper right to either restart or shut down a system.

Figure 16.17: System power options

Controlling Running System Services

You can start, enable, disable, and stop services with graphical tools in Web Console. Click Services on the navigation bar to access the Web Console's services initial page. To manage services, click System Services at the top of the services initial page. Search in the search bar or scroll through the page to select the service you want to manage.

In the example below, select the chronyd.service row to open thee service management page.

Figure 16.18: Services: Initial view

Click Stop, Restart, or Disallow running (mask) as appropriate to manage the service. In this view the service is already running. Additional information related to the service is available by clicking on any of the highlighted links or by scrolling through the service logs displayed below the service management section.

Figure 16.19: Services: Service details and management interface

Configuring Network Interfaces and the Firewall

To manage firewall rules and network interfaces, click Networking on the navigation bar. The following example shows how to gather information about network interfaces and how to manage them.

Figure 16.20: Networking: Initial view

Click the desired interface name in the Interfaces section to access the management page. In this example, the eth0 interface is selected.

Figure 16.21: Networking: Interfaces

The top part of the management page displays network traffic activity for the selected device. Scroll down to view configuration settings and management options.

Figure 16.22: Networking: Interface details

To modify or add configuration options to an interface, click the highlighted links for the desired configuration. In this example, the IPv4 link shows a single IP address and netmask, 172.25.250.10/24 for the eth0 network interface. To add an additional IP address to the eth0 network interface, click the highlighted link.

Figure 16.23: Networking: eth0 configuration section

Click + on the right side of the Manual list selection to add an additional IP address. Enter an IP address and network mask in the appropriate fields. Click Apply to activate the new settings.

Figure 16.24: Adding an IP address to an existing interface

The display automatically switches back to the interface's management page where you can confirm the new IP address.

Figure 16.25: Confirming the new IP address

Administering User Accounts

As a privileged user you can create new user accounts in Web Console. Click Accounts on the navigation bar to view existing accounts. Click Create New Account to open the account management page.

Figure 16.26: Existing user accounts

Enter the information for the new account and then click Create.

Figure 16.27: Creating a new account

The display automatically switches back to the account management page where you can confirm the new user account.

Figure 16.28: Account management page