EX188 Container Operations And Lifecycle — Timed 10 Questions

Question 1

A container named api_gw is configured with a health check. An administrator needs to check the current health status (e.g., healthy, unhealthy, starting) using the command line without reading the full inspect JSON. Which command string achieves this?

10 minute time limit — choose an answer to begin.

Accepted Answer

podman inspect --format='{{json .State.Health.Status}}' api_gw. podman inspect with a Go-template --format flag extracts just the .State.Health.Status field from the container's JSON metadata, returning a single word like healthy, unhealthy, or starting. This is the canonical way to query health status without parsing the full inspect output, and it works identically for podman and docker.

Answer

podman health status api_gw

Answer

podman ps --filter health=unhealthy

Answer

podman status api_gw

Question 2

An administrator wants to generate a systemd unit file for an existing container named web_frontend so it can be managed by systemd. Which command should be run?

Accepted Answer

podman generate systemd --new --name web_frontend. The correct command is `podman generate systemd --new --name web_frontend`, which generates a systemd unit file for the named container. The `--new` flag tells Podman to create a unit that creates a new container each time the service starts, rather than managing an existing container instance.

Answer

systemctl enable --container web_frontend

Answer

podman export systemd web_frontend

Answer

podman systemd generate --name web_frontend

Question 3

An administrator wants to find out which host port is mapped to port 80/tcp inside a running container named proxy_svr, using format templating with podman inspect. Which command accomplishes this?

Accepted Answer

podman inspect --format='{{range $p, $conf := .NetworkSettings.Ports}} {{$p}} -> {{(index $conf 0).HostPort}} {{end}}' proxy_svr. The correct command uses podman inspect with Go template syntax to iterate over the .NetworkSettings.Ports map, extracting each container port and its corresponding host port. The range loop iterates over the map, and for each port binding, it accesses the first element of the slice (index 0) to get the HostPort. This precisely retrieves the host port mapped to container port 80/tcp.

Answer

podman ports proxy_svr

Answer

podman inspect --ports proxy_svr

Answer

podman ps --filter port=80

Question 4

An administrator wants to run a container with a custom health check command that disables health checking entirely for a container that inherited one from its base image. Which flag achieves this?

Accepted Answer

--health-cmd=none. Setting `--health-cmd=none` explicitly overrides any HEALTHCHECK inherited from the base image and disables health checking for the container. Podman interprets the literal string `none` as a directive to turn off the health check rather than to execute a command named 'none'.

Answer

--health-enabled=false

Answer

--disable-health

Answer

--no-healthcheck

Question 5

An administrator wants to forcefully kill a running container named runaway_job immediately by sending the SIGKILL signal. Which command should be used?

Accepted Answer

podman kill runaway_job. The `podman kill` command sends a signal to the main process of a container. By default, it sends SIGKILL, which forcefully terminates the container immediately. This is the correct command to forcefully kill a running container.

Answer

podman terminate runaway_job

Answer

podman halt runaway_job

Answer

podman stop --force runaway_job

Question 6

An administrator needs to manage container lifecycles in Podman. Which TWO of the following commands can be used to start an existing, stopped container? (Choose TWO)

Accepted Answer

podman start. Option C, podman start, is correct because it starts one or more existing, stopped containers by name or ID, resuming them from their stopped state without creating a new container. Option E, podman restart, is correct because it stops and then starts the specified container(s); when applied to an already stopped container, it effectively starts it, so it can be used to bring an existing stopped container back up. Option A, podman exec, is wrong because it runs a new command inside an already running container and fails on a stopped one. Option B, podman run, is wrong because it creates and starts a new container from an image rather than starting an existing stopped container. Option D, podman up, is wrong because it is not a valid Podman command (it belongs to Docker Compose-style tooling).

Answer

podman exec

Answer

podman run

Answer

podman up

Question 7

An administrator wants to examine the internal state, environment variables, or port mappings of a running container. Which TWO commands or techniques are appropriate? (Choose TWO)

Accepted Answer

podman port. Option A, `podman port`, is correct because it specifically queries and displays the port mappings of a running container, showing the mapping between container ports and host ports, which directly addresses the port-mapping part of the scenario. Option C, `podman inspect`, is correct because it returns detailed JSON metadata about a container, including its internal state (such as running status and configuration), environment variables, and port mappings, making it the most comprehensive tool for examining a container's internal details. The unmarked options do not belong: `podman list-ports` (B) is not a valid podman subcommand, `podman env` (D) is not a podman command for inspecting a container's environment, and `podman show-env` (E) is likewise not a real podman subcommand for this purpose.

Answer

podman list-ports

Answer

podman env

Answer

podman show-env

Question 8

An administrator needs to stop and remove a running container in a single workflow. Which TWO of the following approaches accomplish this? (Choose TWO)

Accepted Answer

podman rm -f container_name. podman rm -f forces removal of running containers (stopping them first), and stopping a container before running podman rm is also valid.

Answer

podman kill --remove container_name

Answer

podman delete --force container_name

Answer

podman stop --rm container_name

Question 9

An administrator is managing rootless containers and needs to understand how user namespaces and security isolation function. Which TWO of the following configuration files or tools are directly relevant to rootless user mapping and systemd user persistence? (Choose TWO)

Accepted Answer

/etc/subuid and /etc/subgid. Option D is correct because /etc/subuid and /etc/subgid are the canonical files that define the subordinate UID and GID ranges assigned to each user, which rootless container tools such as Podman and Buildah use to map container root to an unprivileged host UID/GID via user namespaces. Option E is correct because loginctl enable-linger <user> keeps the user's systemd instance (and thus the user manager and any rootless containers started as user services) running after logout, which is essential for persistent rootless container services. Option A is not a real systemctl command or unit target, so it has no role in user mapping or persistence. Option B is incorrect because the actual rootless configuration file is /etc/containers/containers.conf (and storage.conf), not /etc/containers/rootless.conf. Option C is incorrect because subuid/subgid mappings are not stored in /var/lib/podman/subuid.conf; that path is not the standard location for user namespace mapping data.

Answer

systemctl system-wide-users

Answer

/etc/containers/rootless.conf

Answer

/var/lib/podman/subuid.conf

Question 10

An administrator wants to generate a systemd unit file for an existing Podman container named 'app_server' so that it can be managed as a system service. Which command should be used to generate this unit file and write it directly to the user systemd directory?

Accepted Answer

podman generate systemd --new --files --name app_server. The podman generate systemd command creates a systemd unit file for a container. The --new flag generates a unit that creates a new container each time it starts (rather than managing an existing one), --files writes the unit file to disk, and --name app_server specifies the container. This is the correct syntax to generate a unit file for the named container.

Answer

podman export systemd app_server > /etc/systemd/system/app_server.service

Answer

podman service generate --container app_server --output ~/.config/systemd/user/

Answer

podman systemd create --name app_server > ~/.config/systemd/user/container-app_server.service