Chapter 17. Managing containers by using the RHEL web console
You can use the Red Hat Enterprise Linux web console to manage your containers and pods. With the web console, you can create containers as a non-root or root user.
- As a root user, you can create system containers with extra privileges and options.
As a non-root user, you have two options:
- To only create user containers, you can use the web console in its default mode - Limited access.
- To create both user and system containers, click Administrative access in the top panel of the web console page.
For details about differences between root and rootless containers, see Special considerations for rootless containers.
17.1. Creating containers in the web console
You can create a container and add port mappings, volumes, environment variables, health checks, and so on.
Prerequisites
You have installed the RHEL 8 web console.
For instructions, see Installing and enabling the web console.
The
cockpit-podman
add-on is installed:# yum install cockpit-podman
Procedure
Log in to the RHEL 8 web console.
For details, see Logging in to the web console.
- Click Podman containers in the main menu.
- Click .
- In the Name field, enter the name of your container.
Provide desired info in the Details tab.
- Available only with the administrative access: Select the Owner of the container: System or User.
In the Image drop down list select or search the container image in selected registries.
- Optional: Check the Pull latest image checkbox to pull the latest container image.
The Command field specifies the command. You can change the default command if you need.
- Optional: Check the With terminal checkbox to run your container with a terminal.
- The Memory limit field specifies the memory limit for the container. To change the default memory limit, check the checkbox and specify the limit.
- Available only for system containers: In the CPU shares field, specify the relative amount of CPU time. Default value is 1024. Check the checkbox to modify the default value.
Available only for system containers: In the Restart policy drop down menu, select one of the following options:
- No (default value): No action.
- On Failure: Restarts a container on failure.
- Always: Restarts a container when exits or after rebooting the system.
Provide the required information in the Integration tab.
Click
to add port mapping between the container and host system.- Enter the IP address, Host port, Container port and Protocol.
Click
to add volume.- Enter the host path, Container path. You can check the Writable option checkbox to create a writable volume. In the SELinux drop down list, select one of the following options: No Label, Shared or Private.
Click
to add environment variable.- Enter the Key and Value.
Provide the required information in the Health check tab.
- In the Command fields, enter the 'healthcheck' command.
Specify the healthcheck options:
- Interval (default is 30 seconds)
- Timeout (default is 30 seconds)
- Start period
- Retries (default is 3)
When unhealthy: Select one of the following options:
- No action (default): Take no action.
- Restart: Restart the container.
- Stop: Stop the container.
- Force stop: Force stops the container, it does not wait for the container to exit.
- Click to create and run the container.
You can click
to only create the container.Verification
- Click Podman containers in the main menu. You can see the newly created container in the Containers table.
17.2. Inspecting containers in the web console
You can display detailed information about a container in the web console.
Prerequisites
- The container was created.
You have installed the RHEL 8 web console.
For instructions, see Installing and enabling the web console.
The
cockpit-podman
add-on is installed:# yum install cockpit-podman
Procedure
include::common-content/snip_web-console-log-in-step.adoc[] . Click *Podman containers* in the main menu. . Click the btn:[>] arrow icon to see details of the container. * In the *Details* tab, you can see container ID, Image, Command, Created (timestamp when the container was created), and its State. ** _Available only for system containers_: You can also see IP address, MAC address, and Gateway address. * In the *Integration* tab, you can see environment variables, port mappings, and volumes. * In the *Log* tab, you can see container logs. * In the *Console* tab, you can interact with the container using the command line.
17.3. Changing the state of containers in the web console
In the Red Hat Enterprise Linux web console, you can start, stop, restart, pause, and rename containers on the system.
Prerequisites
- The container was created.
You have installed the RHEL 8 web console.
For instructions, see Installing and enabling the web console.
The
cockpit-podman
add-on is installed:# yum install cockpit-podman
Procedure
Log in to the RHEL 8 web console.
For details, see Logging in to the web console.
- Click Podman containers in the main menu.
In the Containers table, select the container you want to modify and click the overflow menu and select the action you want to perform:
- Start
- Stop
- Force stop
- Restart
- Force restart
- Pause
- Rename
17.4. Committing containers in the web console
You can create a new image based on the current state of the container.
Prerequisites
- The container was created.
You have installed the RHEL 8 web console.
For instructions, see Installing and enabling the web console.
The
cockpit-podman
add-on is installed:# yum install cockpit-podman
Procedure
Log in to the RHEL 8 web console.
For details, see Logging in to the web console.
- Click Podman containers in the main menu.
- In the Containers table, select the container you want to modify and click the overflow menu and select Commit.
In the Commit container form, add the following details:
- In the New image name field, enter the image name.
- Optional: In the Tag field, enter the tag.
- Optional: In the Author field, enter your name.
- Optional: In the Command field, change command if you need.
Optional: Check the Options you need:
- Pause container when creating image: The container and its processes are paused while the image is committed.
- Use legacy Docker format: if you do not use the Docker image format, the OCI format is used.
- Click .
Verification
- Click the Podman containers in the main menu. You can see the newly created image in the Images table.
17.5. Creating a container checkpoint in the web console
Using the web console, you can set a checkpoint on a running container or an individual application and store its state to disk.
Creating a checkpoint is available only for system containers.
Prerequisites
- The container is running.
You have installed the RHEL 8 web console.
For instructions, see Installing and enabling the web console.
The
cockpit-podman
add-on is installed:# yum install cockpit-podman
Procedure
Log in to the RHEL 8 web console.
For details, see Logging in to the web console.
- Click Podman containers in the main menu.
- In the Containers table, select the container you want to modify and click the overflow icon menu and select Checkpoint.
Optional: In the Checkpoint container form, check the options you need:
- Keep all temporary checkpoint files: keep all temporary log and statistics files created by CRIU during checkpointing. These files are not deleted if checkpointing fails for further debugging.
- Leave running after writing checkpoint to disk: leave the container running after checkpointing instead of stopping it.
- Support preserving established TCP connections
- Click .
Verification
- Click the Podman containers in the main menu. Select the container you checkpointed, click the overflow menu icon and verify that there is a Restore option.
17.6. Restoring a container checkpoint in the web console
You can use data saved to restore the container after a reboot at the same point in time it was checkpointed.
Creating a checkpoint is available only for system containers.
Prerequisites
- The container was checkpointed.
You have installed the RHEL 8 web console.
For instructions, see Installing and enabling the web console.
The
cockpit-podman
add-on is installed:# yum install cockpit-podman
Procedure
Log in to the RHEL 8 web console.
For details, see Logging in to the web console.
- Click Podman containers in the main menu.
- In the Containers table, select the container you want to modify and click the overflow menu and select Restore.
Optional: In the Restore container form, check the options you need:
- Keep all temporary checkpoint files: Keep all temporary log and statistics files created by CRIU during checkpointing. These files are not deleted if checkpointing fails for further debugging.
- Restore with established TCP connections
- Ignore IP address if set statically: If the container was started with IP address the restored container also tries to use that IP address and restore fails if that IP address is already in use. This option is applicable if you added port mapping in the Integration tab when you create the container.
- Ignore MAC address if set statically: If the container was started with MAC address the restored container also tries to use that MAC address and restore fails if that MAC address is already in use.
- Click .
Verification
- Click the Podman containers in the main menu. You can see that the restored container in the Containers table is running.
17.7. Deleting containers in the web console
You can delete an existing container using the web console.
Prerequisites
- The container exists on your system.
You have installed the RHEL 8 web console.
For instructions, see Installing and enabling the web console.
The
cockpit-podman
add-on is installed:# yum install cockpit-podman
Procedure
Log in to the RHEL 8 web console.
For details, see Logging in to the web console.
- Click Podman containers in the main menu.
- In the Containers table, select the container you want to delete and click the overflow menu and select Delete.
- The pop-up window appears. Click Delete to confirm your choice.
Verification
- Click the Podman containers in the main menu. The deleted container should not be listed in the Containers table.
17.8. Creating pods in the web console
You can create pods in the RHEL web console interface.
Prerequisites
You have installed the RHEL 8 web console.
For instructions, see Installing and enabling the web console.
The
cockpit-podman
add-on is installed:# yum install cockpit-podman
Procedure
Log in to the RHEL 8 web console.
For details, see Logging in to the web console.
- Click Podman containers in the main menu.
- Click .
Provide desired information in the Create pod form:
- Available only with the administrative access: Select the Owner of the container: System or User.
- In the Name field, enter the name of your container.
Click
to add port mapping between container and host system.- Enter the IP address, Host port, Container port and Protocol.
Click
to add volume.- Enter the host path, Container path. You can check the Writable checkbox to create a writable volume. In the SELinux drop down list, select one of the following options: No Label, Shared or Private.
- Click .
Verification
- Click Podman containers in the main menu. You can see the newly created pod in the Containers table.
17.9. Creating containers in the pod in the web console
You can create a container in a pod.
Prerequisites
You have installed the RHEL 8 web console.
For instructions, see Installing and enabling the web console.
The
cockpit-podman
add-on is installed:# yum install cockpit-podman
Procedure
Log in to the RHEL 8 web console.
For details, see Logging in to the web console.
- Click Podman containers in the main menu.
- Click .
- In the Name field, enter the name of your container.
Provide the required information in the Details tab.
- Available only with the administrative access: Select the Owner of the container: System or User.
In the Image drop down list select or search the container image in selected registries.
- Optional: Check the Pull latest image checkbox to pull the latest container image.
The Command field specifies the command. You can change the default command if you need.
- Optional: Check the With terminal checkbox to run your container with a terminal.
- The Memory limit field specifies the memory limit for the container. To change the default memory limit, check the checkbox and specify the limit.
- Available only for system containers: In the CPU shares field, specify the relative amount of CPU time. Default value is 1024. Check the checkbox to modify the default value.
Available only for system containers: In the Restart policy drop down menu, select one of the following options:
- No (default value): No action.
- On Failure: Restarts a container on failure.
- Always: Restarts container when exits or after system boot.
Provide the required information in the Integration tab.
Click
to add port mapping between the container and host system.- Enter the IP address, Host port, Container port and Protocol.
Click
to add volume.- Enter the host path, Container path. You can check the Writable option checkbox to create a writable volume. In the SELinux drop down list, select one of the following options: No Label, Shared, or Private.
Click
to add environment variable.- Enter the Key and Value.
Provide the required information in the Health check tab.
- In the Command fields, enter the healthcheck command.
Specify the healthcheck options:
- Interval (default is 30 seconds)
- Timeout (default is 30 seconds)
- Start period
- Retries (default is 3)
When unhealthy: Select one of the following options:
- No action (default): Take no action.
- Restart: Restart the container.
- Stop: Stop the container.
- Force stop: Force stops the container, it does not wait for the container to exit.
The owner of the container is the same as the owner of the pod.
In the pod, you can inspect containers, change the status of containers, commit containers, or delete containers.
Verification
- Click Podman containers in the main menu. You can see the newly created container in the pod under the Containers table.
17.10. Changing the state of pods in the web console
You can change the status of the pod.
Prerequisites
- The pod was created.
You have installed the RHEL 8 web console.
For instructions, see Installing and enabling the web console.
The
cockpit-podman
add-on is installed:# yum install cockpit-podman
Procedure
Log in to the RHEL 8 web console.
For details, see Logging in to the web console.
- Click Podman containers in the main menu.
In the Containers table, select the pod you want to modify and click the overflow menu and select the action you want to perform:
- Start
- Stop
- Force stop
- Restart
- Force restart
- Pause
17.11. Deleting pods in the web console
You can delete an existing pod using the web console.
Prerequisites
- The pod exists on your system.
You have installed the RHEL 8 web console.
For instructions, see Installing and enabling the web console.
The
cockpit-podman
add-on is installed:# yum install cockpit-podman
Procedure
Log in to the RHEL 8 web console.
For details, see Logging in to the web console.
- Click Podman containers in the main menu.
- In the Containers table, select the pod you want to delete and click the overflow menu and select Delete.
- In the following pop-up window, click Delete to confirm your choice.
You remove all containers in the pod.
Verification
- Click the Podman containers in the main menu. The deleted pod should not be listed in the Containers table.