An essential part of managing containers is working with container images. In this lab, we install and configure a Podman environment and use Podman and Skopeo to manage container images in our environment. Upon completion, you can install and configure a Podman environment and use it to manage container images.
Learning Objectives
Successfully complete this lab by achieving the following learning objectives:
- Install Podman Using yum or Application Streams
- Install
podmanon your RHEL server usingyum. Alternatively, you can use Application Streams to install thecontainer-toolspackage stream.Note: If you use Application Streams, make sure you use the default stream.
2.We need to add
'localhost'to the empty line for[registries.insecure]in the/etc/containers/registries.conffile to specify our local container registry as an insecure registry. You’ll need to do this usingsudo.- Install
- Start the Local Container Image Registry
- A local container image registry has been pre-configured on your server. Before we can use it, we need to start it.
- Run the script (
registry.sh), provided in thecloud_userhome directory. Run this script withsudo, as it requiresrootprivilages.
- Manage Container Images Using Podman
The
podmancommand comes with quite a bit of container management functionality included. Let’s try the following:- Check your installed version of
podman - Check out the help information on the
podmancommand - Check out the help information on the
podman imagecommand - Use
podmanto search for theubi:latestcontainer images - Use
podmanto pull a copy of theregistry.access.redhat.com/ubi8/ubi:latestcontainer image - Compare the
podman imagescommand to thepodman image listcommand - Compare the
podman inspect ubicommand to thepodman image inspect ubicommand - Add the
myubitag to theubi:latestimage - List our container images again
- Log in to the local container inage registry at
localhost:5000 - Push the
ubi:latestimage in our local container image storage to the registry running on our lab server- Tag the
ubi:latestimage with the target oflocalhost:5000/ubi8/ubi - Push the image to
localhost:5000/ubi8/ubi:latest- Use the
--remove-signaturesswitch
- Use the
- Tag the
- Check the local registry’s contents using
curl -u cloud_user https://localhost:5000/v2/_catalogand thecloud_userpassword - Remove the
myubitag - List our container images again
- Remove the image with no tags using the
imageID - List our container images again
- Use
podmanto search our local registry - Using
podman, log out of the local container registry
- Check your installed version of
- Manage Container Images Using Skopeo
Even though the
podmancommand can be used to perform container image management, taking things to the next level requiresskopeo. Let’s try the following withskopeo:- Check your installed version of
skopeo - Check out the help information on the
skopeocommand - Check out the help information on the
skopeo inspectcommand - Use
skopeoto log in to the local container image registry atlocalhost:5000 - Use
skopeoto copy a container image directly fromdocker://registry.access.redhat.com/ubi7/ubi:latestto our local registry (docker://localhost:5000/ubi7/ubi) - Check the local registry’s contents using
curl -u cloud_user https://localhost:5000/v2/_catalogand thecloud_userpassword - Use
skopeoto sync a container image fromdocker://registry.access.redhat.com/ubi7/ubi:latestto our local registry (docker://localhost:5000/ubi7/ubi) - Use
skopeoto inspect theubi7andubi8images on the local container registry - Use
skopeoto list the tags on theubi7andubi8images on the local container registry - Use
podmanto search our local registry (localhost:5000/ubi) - Use
skopeoto log out of the local container image registry atlocalhost:5000
- Check your installed version of
