Removing images in Docker - Step-by-Step Execution

Process Flow - Removing images

List images

↓

Choose image to remove

↓

Run docker rmi command

↓

Check if image removed

↓

Success or error message

The flow shows listing images, selecting one, removing it with a command, and verifying removal.

Execution Sample

Docker

docker images
# Lists all images

docker rmi alpine:latest
# Removes the alpine image

docker images
# Lists images again to confirm removal

This sequence lists images, removes the alpine image, then lists images again to confirm it is gone.

Process Table

Step	Command	Action	Result	Output
1	docker images	List all images	Images listed	REPOSITORY TAG IMAGE ID CREATED SIZE alpine latest abc123def456 2 weeks ago 5MB ubuntu 20.04 def456abc123 3 weeks ago 72MB
2	docker rmi alpine:latest	Remove alpine image	Image removed	Untagged: alpine:latest Deleted: sha256:abc123def456
3	docker images	List images again	Alpine image gone	REPOSITORY TAG IMAGE ID CREATED SIZE ubuntu 20.04 def456abc123 3 weeks ago 72MB

💡 Alpine image removed successfully, no longer listed.

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3
Images List	[]	[alpine:latest, ubuntu:20.04]	[ubuntu:20.04]	[ubuntu:20.04]

Key Moments - 2 Insights

Why does the image still appear if I try to remove it but get an error?

If the image is used by a running container, removal fails. See step 2 output for errors. You must stop containers first.

What happens if I remove an image tag but the image has multiple tags?

Only the specified tag is removed (untagged). The image stays if other tags exist. Step 2 shows 'Untagged' message.

Visual Quiz - 3 Questions

Look at the execution table, what images are listed after step 1?

A Only ubuntu:20.04

B alpine:latest and ubuntu:20.04

C No images listed

D Only alpine:latest

💡 Hint

Check the Output column in step 1 of the execution_table.

At which step is the alpine image removed from the list?

A Step 1

B Step 3

C Step 2

D It is never removed

💡 Hint

Look at the Action and Result columns in step 2.

If you tried to remove an image used by a running container, what would happen?

A Command fails with error

B Image is removed anyway

C Image is renamed

D Image is paused

💡 Hint

Refer to key_moments about removal errors when containers use the image.

Concept Snapshot

docker images - lists all images

docker rmi <image> - removes specified image

Removal fails if image is used by containers

Check images again to confirm removal

Use docker ps to stop containers before removal

Full Transcript

This visual execution shows how to remove Docker images step-by-step. First, you list all images with 'docker images'. Then you remove a chosen image using 'docker rmi <image>'. Finally, you list images again to confirm the removal. The execution table tracks commands, actions, and outputs. The variable tracker shows how the images list changes after each step. Key moments explain common confusions like removal errors if containers use the image. The quiz tests understanding of image listing, removal step, and error cases. The snapshot summarizes the commands and rules for removing images.