Docker CLI Cheatsheet - Run, Build & Compose Commands

A Docker command reference for app developers and SREs, covering image build, container lifecycle, networks & volumes, Compose orchestration, and resource cleanup. Unlike OS-level container tools, Docker layered images and isolation are what matter when you must debug startup failures, mapping mistakes, or image bloat. By the end you can bring a service up from an image and troubleshoot the three most frequent problems: startup, networking, and disk usage.

Containers & Orchestration·52 commands·Last updated 2026-09-10
dockercomposeImagesContainers

Typical Use Case

For app developers and SREs: run a local service from an image, build reproducible images, orchestrate multi-container stacks with Compose, and independently diagnose startup failures, port-mapping mistakes, image bloat, and disk-full conditions.

Image 8

docker images
List local images, add -a to include intermediate layers
docker pull nginx:alpine
Pull image with tag, defaults to latest if omitted
docker build -t app:1.0 .
Build and tag from Dockerfile in current dir
docker rmi <image>
Remove image, stop container first or use -f
docker tag app:1.0 reg/app:1.0
Tag image for registry push
docker save -o app.tar app:1.0
Export image as tar for offline transfer
docker load -i app.tar
Load image from tar file, useful in offline environments
docker pull alpine:3.20 --platform=linux/amd64
Pull image for a specific platform, e.g. amd64 on ARM Mac

Container 9

docker ps -a
List all containers including stopped
docker run -d -p 8080:80 --name web nginx
Run detached, map port, name container
docker exec -it web sh
Interactive shell into running container
docker logs -f --tail 100 web
Follow last 100 lines of container logs
docker stop web && docker rm web
Stop and remove container
docker inspect web
Full container config JSON for network/mount debugging
docker start web && docker restart web
Start or restart a stopped container
docker stats
Live CPU/memory/network I/O stats for all containers
docker top web
List running processes inside a container

Network & Volume 8

docker network ls
List networks, check here first for inter-container access
docker network create appnet
Create custom bridge network for name-based discovery
docker network connect appnet web
Connect a running container to a network
docker volume ls
List volumes
docker run -v data:/var/lib/app app
Mount named volume for persistence
docker run -v $(pwd):/app app
Bind mount current dir, common in dev
docker volume create appdata
Create a named volume for shared data
docker volume prune
Remove all unused volumes

Registry 6

docker login
Log in to Docker Hub, required before push
docker login registry.example.com
Log in to a private registry (Harbor/Registry)
docker push app:1.0
Push image to remote registry, must tag first
docker pull ubuntu:22.04
Pull Ubuntu 22.04 image from Docker Hub
docker search nginx
Search Docker Hub for official images
docker logout
Log out from the current registry

Build & Debug 7

docker build -t app:1.0 --no-cache .
Force rebuild without cache layers
docker build -t app:1.0 --target=dev .
Build only up to a specific multi-stage target
docker history app:1.0
View image build history, layer sizes and commands
docker diff <container>
Inspect filesystem changes in a container
docker cp app.conf web:/etc/nginx/conf.d/
Copy local config file into a container
docker cp web:/var/log/nginx/access.log ./
Copy a log file from a container to local
docker events --since 5m
Stream Docker daemon events in real time

Compose & Cleanup 9

docker compose up -d
Start Compose project in background
docker compose logs -f svc
Follow logs for a specific service
docker compose down
Stop and remove containers, networks; add -v for volumes
docker compose ps
List container status for all services in Compose project
docker compose restart
Restart all or specified services
docker system df
Check disk usage by images/containers/volumes
docker system prune -a
Clean all unused images and containers, use -a with caution
docker container prune
Remove all stopped containers
docker image prune -a
Remove all unused images to free disk space

FAQ 5

Q: How to clean up all unused Docker resources?
A: docker system prune -a removes all unused images, containers, networks, and build cache. Add --volumes to also remove volumes.
Q: How to view container logs?
A: docker logs <container> shows full logs, add -f to follow, --tail 50 for last 50 lines, --since 5m for last 5 minutes.
Q: How to enter a running container?
A: docker exec -it <container> /bin/bash (or /bin/sh). Exit with exit or Ctrl+D.
Q: How to copy files between host and container?
A: docker cp <src> <container>:<dest> to copy in, docker cp <container>:<src> <dest> to copy out.
Q: What restart policies are available?
A: --restart=no (default)/on-failure/always/unless-stopped. unless-stopped is common for production.

Parameter matrix

ParameterEffectExample
-dRun the container detached in the backgrounddocker run -d -p 8080:80 nginx
-pPublish a port, written hostPort:containerPortdocker run -d -p 8080:80 nginx
--nameGive the container a readable name for later commandsdocker run -d --name web nginx
-vMount a volume or bind directory so data outlives the containerdocker run -v /data:/app/data nginx
--rmDelete the container on exit so nothing is left behinddocker run --rm alpine echo hi
-eInject an environment variable into the containerdocker run -e NODE_ENV=prod app
--networkAttach to a named network so containers resolve each other by namedocker run --network appnet web
-itAllocate an interactive TTY, used when entering a container shelldocker exec -it web sh
--restartRestart policy applied after exit: no, on-failure or alwaysdocker run -d --restart unless-stopped web
--platformTarget a specific architecture, such as amd64 images on an ARM Macdocker pull --platform=linux/amd64 nginx
--no-cacheIgnore the layer cache at build time and rerun every layerdocker build --no-cache -t app .
-fPoint at a specific Dockerfiledocker build -f Dockerfile.prod -t app .

Common pitfalls

SymptomAfter publishing a port, nothing on the host or the network can reach the service.

CauseThe host:container order is reversed, or the process inside listens on 127.0.0.1 instead of 0.0.0.0.

FixRemember -p 8080:80 means host port first; the application inside the container must bind 0.0.0.0 to be reachable.

Symptomdocker exec fails with OCI runtime exec failed: exec: "bash": not found.

CauseThe image is built on alpine or scratch, neither of which ships bash.

FixFall back to sh with docker exec -it web sh, or install bash in the Dockerfile via apk add bash first.

SymptomEvery docker build re-pulls the base image and never hits the layer cache.

CauseThe base image uses the latest tag, or frequently changing files such as source are copied before stable ones.

FixPin the base version (node:20-alpine) and put dependency installation ahead of the source COPY.

SymptomBuild or run reports No space left on device and the host disk is full.

CauseStopped containers, dangling (<none>) images and unused volumes have piled up over time.

FixInspect usage with docker system df, reclaim space with docker system prune -a --volumes, and schedule that cleanup on production hosts.

SymptomA container is killed and docker inspect shows ExitCode 137.

CauseIt exceeded its memory limit and the OOM killer sent SIGKILL, which surfaces as 137.

FixWatch live usage with docker stats, then set a sensible --memory limit or reduce what the application allocates.

SymptomAn image pulled on an ARM Mac fails with exec format error on an x86 server.

CauseThe image architecture does not match the runtime: arm64 versus amd64.

FixState the target platform explicitly at build or pull time, for example docker build --platform=linux/amd64 -t app ., and push a matching image.

SymptomConfig edits made inside the container vanish as soon as the image is rebuilt.

CauseThe container filesystem is ephemeral and no persistent volume was mounted.

FixAttach a named volume or bind mount with -v /host/path:/container/path for anything that has to survive.

Troubleshooting

  1. 1Container will not start or exits immediately: read the logs

    docker logs --tail 50 web

    The tail usually holds the startup failure: bad config, missing dependency or a port already in use.

  2. 2Check the exit status and reason

    docker inspect -f '{{.State}}' web

    ExitCode 0 is a clean exit, 137 is OOM, 139 a segfault and so on; read the Reason field alongside it.

  3. 3List every container port when a mapping looks wrong

    docker ps --format '{{.Names}}\t{{.Ports}}'

    Confirm 0.0.0.0:8080->80/tcp is what you expected and that no other container already holds the port.

  4. 4See what is consuming disk when the volume fills up

    docker system df

    Break the figure down by Images, Containers and Volumes, then clean up the category that dominates.

  5. 5Enter the container to check network connectivity

    docker exec -it web sh -c "cat /etc/resolv.conf; ping -c1 8.8.8.8"

    Testing DNS and outbound reach separately tells you whether the problem is your network config or the image.

Command Examples

Run nginx in the background with a port mapping

docker run -d --name web -p 8080:80 nginx:alpine

-p 8080:80 表示宿主机 8080 转发到容器 80,访问 http://localhost:8080 即可看到 nginx 欢迎页;-d 让容器后台运行,--name 便于后续用名字管理。

Output

b3f2c1a9d8e4f5a6b7c8d9e0f1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b

Bind-mount the current directory and enter an interactive shell

docker run -it --rm -v "$(pwd)":/app -w /app node:18-alpine sh

-v 把当前目录挂载到容器 /app,-w 设为工作目录,--rm 退出时自动删除容器,-it 提供交互终端,适合本地调试 Node 应用而无需本地安装 Node。

Follow the last 100 lines of a container log

docker logs -f --tail 100 web

-f 实时跟踪后续日志,--tail 100 只从最后 100 行开始输出,排查启动崩溃或请求异常时第一命令。

Prune unused images to free disk space

docker system df

先 docker system df 看占用,再决定是否 docker image prune -a 清理所有未被容器引用的镜像;删镜像前务必确认没有需要保留的版本。

Output

TYPE            TOTAL     ACTIVE    SIZE      RECLAIMABLE
Images          12        5         1.4GB     621.5MB (43%)
Containers      8         3         5.6MB     5.6MB (100%)

Common Pitfalls

  • docker run -p is host_port:container_port — reversed means external access never works, and it fails silently, the hardest thing to debug.
  • prune -a removes every image no container is using, including freshly built but not-yet-run versions. Run docker images first on production.
  • An "executable file not found" error usually means the image lacks that shell; Alpine ships only sh, so use docker exec -it <c> sh.
  • Flags like -e env vars and port mappings cannot be changed after the container starts; you must stop, remove, and re-run.
  • A permission denied on bind mounts often comes from a mismatch between the host directory owner and the container user.

Tips

  • In docker run -p, it's host_port:container_port — reversing them blocks external access.
  • If exec says "executable file not found", switch to sh: Alpine images usually lack bash.
  • prune -a removes all images not used by any container — verify with docker images first on production.
  • docker system df quickly shows disk usage — run it periodically to avoid /var/lib/docker filling up.
  • docker compose restart is faster than down/up and does not rebuild networks or volumes — best for nginx config changes.

FAQ

What is the difference between docker run and docker start?

docker run creates and starts a new container from an image (first launch); docker start restarts an existing but stopped container without creating a new instance. Use start to debug existing state, run to deploy new services.

How do I free up disk space used by Docker?

Use docker system prune to remove stopped containers, dangling images, and build cache; add -a to also remove all images not referenced by any container. Use cautiously in production to avoid deleting valuable images.

What is the relationship between a container and an image?

An image is a read-only template containing the code, dependencies, and config needed to run an app; a container is a running instance of that image with a writable layer on top. One image can launch multiple isolated containers.

Why does my container exit immediately with status Exited (0)?

Check the exit code with docker ps -a: Exited (0) usually means the foreground process did not stay alive (the command finished and exited), so use -it or switch to a foreground command in the Dockerfile (e.g. CMD ["nginx","-g","daemon off;"]). For non-zero codes, run docker logs <id> to read the real error, usually a missing dependency, permission, or wrong config path.

Why can I not reach localhost from inside a container?

Inside a container, localhost refers to the container itself, not the host, so host services are unreachable via localhost. To reach a host service, use the default bridge gateway IP (host.docker.internal on macOS/Windows, --network host or the host LAN IP on Linux). To make containers talk to each other, join them to a custom network and address them by container name.

Official References

Each command links to its official documentation below, so you can verify the latest usage and read deeper.

Maintained by LaoHand

Publicly updated on Sep 10, 2026, continuously proofread against official docs.

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