EX188 Red Hat Certified Specialist in Containers Exam Prep

Compare container concepts, Podman versus Docker engines, rootless operation, and outline container infrastructure from image registries docker.io and quay.io to runtime and docker image format.

learn to run containers with podman by logging into registries, pulling images, and running both system and application containers, using interactive shells and detach mode.

Compare rootless and root containers by showing that rootless containers lack an IP address, while root containers have one, using podman and docker examples.

Examine how rootless containers differ from root containers in port binding, showing that privileged ports like 80 cannot be exposed, and teach using non-privileged ports such as 8080 or 8090 instead.

Search for the BusyBox image with Podman, pull and inspect to identify the default shell, then run an interactive container, create directories, and generate a hostname-based info.txt.

Learn to create a custom container image with Podman commit from a running container, using an httpd example and tagging, while noting Dockerfile as the alternative method.

Generate container images with podman commit by pulling BusyBox from a docker registry, running in detach, editing /var/logs, and committing changes as logs in localhost BusyBox.

Pull and run a BusyBox image with Podman in detach mode, naming the container. Create a /var/logs directory inside the running container, then commit changes to a new image.

Learn how to save and load podman images to and from archive tar files, enabling backups, sharing, and migrations when remote registries are unavailable.

Learn to search for and download the alpine image, back it up with podman save, remove the local image, restore it with podman load, and verify the restored image.

Learn how to search, pull, save, remove, and load alpine images with Podman, create and restore from tar archives, and manage local images.

Learn the theory of dockerfiles, or container files, and master core instructions such as from, copy, add, run, entrypoint, cmd, env, workdir, user, and expose.

Explore building a Dockerfile using a UBI base image with podman, applying from, copy, and cmd instructions to create and run a text-based browser in a container.

This lecture demonstrates using cmd and entrypoint together in a Dockerfile, configuring a Python HTTP server, and clarifying the correct order: entrypoint is the main command and cmd supplies arguments.

Demonstrate using expose and label to document port 8080 and the container maintainer. Build and run a Python web server with podman, publish an index.html page, and verify via localhost:8080.

Explore env and build-arg instructions in docker files, pass a version from the command line, and print it at container startup using an environment variable and cmd.

Create the lab four directory, use a ubi base image for the container file, copy userinfo ssh to /usr/local/bin, chmod +x, and set an entrypoint for an interactive podman shell.

Explore Podman volumes and why they matter for multiple database instances sharing data; create, inspect, and mount a Podman volume named db data for a MySQL container.

Learn to set correct SELinux context labels and container file types for Podman, enabling secure binding of a local directory to a container through chown, restorecon, and manage f context.

Bind a local nginx data directory to a podman container using bitnami nginx image, manage ownership and SELinux labels, detach the container, expose port 8080, and curl localhost:8080 to verify.

Learn to pull and run a bitnami nginx image with Podman, set ownership to uid 1001 and container_file_t SELinux labels, mount nginx_data to the container and expose port 8080.

Set up a local private registry with Podman on port 5000, push and pull images using non-TLS methods by setting TLS verify to false, and manage alpine images on localhost.

Configure systemd unit files generated by podman to keep a httpd container running across reboots and enable it to start automatically on startup.

Configure a persistent MySQL service with a Bitnami image, running a container named Udemy DB on port 32000 with credentials, mounting a host directory, and enabling reboot persistence.

Pull, inspect, and run a MySQL podman container named Udemy DB on port 1000 with data mounted. Set ownership and labels, and enable systemd persistence to survive reboots.

Explore podman compose and its role in building microservice infrastructures. Install and verify Podman compose in a lab environment, and prepare to write a compose.yaml for synchronized multi-container deployments.

Learn to build a Podman compose microservice with nginx and redis, using networks, volumes, environment settings, and port mappings, by writing a correct YAML file.

Configure podman compose by creating a service network and data storage, then deploy a webapp with httpd on port 8082 and a PostgreSQL server with a mounted volume.

Define a microservice with podman compose via a yaml file, creating services, networks, and volumes, connecting a web app and data server to a shared network, then run detached.

Learn to troubleshoot podman containers by using podman logs and exec to inspect a running container, and use sudo nsenter to access a container's namespace when commands are unavailable.

Execute podman container troubleshooting in lab eight, completing tasks: pull a minimal image from a registry, run a detached container named minimal container, verify ping, and use nsenter for troubleshooting.

Run a container named minimal container with this image, verify it runs, and troubleshoot using nsenter to ping google.com from the container's process id.