Data Analysis & Reporting Flashcards

You want to filter `docker events` to only show events for a specific container image. Which flag do you use?

Answer: --filter image=

`docker events --filter image=` restricts output to events involving that specific image.

Which metric is NOT reported by `docker stats`?

Answer: Number of open file descriptors

`docker stats` reports CPU %, memory, network I/O, and block I/O but does not show open file descriptor counts.

When using the `gelf` log driver, logs are sent to which type of endpoint?

Answer: A Graylog Extended Log Format UDP/TCP endpoint

The `gelf` driver sends logs in Graylog Extended Log Format to a Graylog or compatible GELF endpoint.

A container's health check is reporting `unhealthy`. Which command gives you the detailed health check output history?

Answer: docker inspect

`docker inspect` includes a `Health` field with the last five health check results and their output.

What format does `docker inspect` use to output container metadata by default?

Answer: JSON

`docker inspect` outputs container metadata as a JSON array by default.

Which command would show how much reclaimable space can be freed by removing unused Docker objects?

Answer: docker system df

`docker system df` shows both total and reclaimable sizes for images, containers, and volumes.

To export Prometheus-compatible metrics from the Docker daemon, which configuration option must be enabled?

Answer: "experimental": true and "metrics-addr"

Enabling experimental mode and setting `metrics-addr` in `daemon.json` exposes a Prometheus metrics endpoint.