Docker images

Here’s a comprehensive list of Docker commands related to images, broken down by category, with explanations and examples:

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1. Pulling and Searching Images

Command	Purpose	Example
docker pull <image>	Download an image from a registry (e.g., Docker Hub)	docker pull nginx:latest
docker search <image>	Search for an image in Docker Hub	docker search postgres

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2. Listing Images

Command	Purpose	Example
docker images or docker image ls	List all local images	docker images
docker image ls -a	List all images including intermediate layers	docker image ls -a
docker image ls --filter "dangling=true"	List dangling (untagged) images	docker image ls --filter "dangling=true"

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3. Building Images

Command	Purpose	Example
docker build -t <name>:<tag> <path>	Build an image from a Dockerfile	docker build -t myapp:1.0 .
docker build --file <Dockerfile>	Specify a Dockerfile with a different name	docker build -t myapp:1.0 -f Dockerfile.dev .
docker build --no-cache	Build an image without using cache	docker build --no-cache -t myapp:1.0 .
docker build --pull	Always attempt to pull a newer version of the base image	docker build --pull -t myapp:1.0 .

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4. Tagging Images

Command	Purpose	Example
docker tag <source> <target>	Add a tag to an existing image	docker tag myapp:1.0 myrepo/myapp:1.0

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5. Pushing Images

Command	Purpose	Example
docker push <repository>:<tag>	Push an image to a registry	docker push myrepo/myapp:1.0

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6. Inspecting Images

Command	Purpose	Example
docker inspect <image>	Show detailed info about an image	docker inspect nginx:latest
docker history <image>	Show image layer history	docker history myapp:1.0
docker image inspect <image>	Same as docker inspect but specifically for images	docker image inspect myapp:1.0

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7. Removing Images

Command	Purpose	Example
docker rmi <image>	Remove a specific image	docker rmi myapp:1.0
docker image prune	Remove dangling images (untagged)	docker image prune
docker image prune -a	Remove all unused images	docker image prune -a

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8. Saving & Loading Images

Command	Purpose	Example
docker save -o <file.tar> <image>	Save an image to a tar file	docker save -o myapp.tar myapp:1.0
docker load -i <file.tar>	Load an image from a tar file	docker load -i myapp.tar

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9. Other Useful Image Commands

Command	Purpose	Example
docker image ls --format "{{.Repository}}:{{.Tag}}"	List images in a custom format	docker image ls --format "{{.Repository}}:{{.Tag}}"
docker image prune --filter "label=<key>=<value>"	Remove images based on labels	docker image prune --filter "label=stage=dev"

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✅ Tips for Working with Docker Images

1. Use tags to version your images clearly (:latest is not always best for production).
2. Clean up unused images regularly to save disk space (docker image prune -a).
3. Use small base images like Alpine to reduce image size.
4. Inspect layers (docker history) to understand how each instruction affects size.
5. Multi-stage builds help reduce final image size while keeping Dockerfile maintainable.